ASTEROID LIGHTCURVE DATA BASE (LCDB) Revised 2019 September 8 ******************************************************************************* SPECIAL NOTICES ******************************************************************************* See Section 5 "SPARSE DATA AND WIDE-FIELD SURVEYS" See Section 6, "NUMBERS OF INTEREST" New: Section 7, "REFERENCES". This list the citations for the references mentioned in this file. The Min/Max Amplitude values in the Summary table are based only on detail lines that have a U >= 2- ratings. If the U code is empty or U <= 1+, the detail line min/max amplitudes are not considered. Floating point numbers are stored as strings in the LCDB. This preserves the original precision of the data. It is up to the end user to maintain the original precision if/when converting string representations to real values. N.B. All lightcurve amplitudes are peak-to-peak, not average-to-peak. ******************************************************************************* 1.0.0 INTRODUCTION -------------------------------------------------------------------------------- The Asteroid Lightcurve Data Base (LCDB) is a set of tables generated from a MySQL database that includes information directly and indirectly obtained from observations made to determine the period and/or amplitude of asteroid lightcurves. The information is taken from numerous journals and other sources. It's main purpose is to provide a central location for basic information about asteroid rotation rates and related information that can be used in statistical studies involving a few or many parameters. Some of the data are obtained directly from the observations while other data are inferred or calculated based on orbital characteristics, assumed class, etc. Sections below explain in detail which data are direct and indirectly obtained and, for the latter, their derivation. N.B. Even direct data should be confirmed by reference to the original works whenever possible. Indirect data are provided for information purposes only. They should not be used in critical studies. 1.1.0 AUTHOR INFORMATION ------------------------- These data tables are maintained by Brian D. Warner (Center for Solar System Studies/MoreData!, Alan Harris (MoreData!), and Petr Pravec (Astronomical Institute, Prague, Czech Republic). For basic information on the database or updated versions of the tables, contact: Brian D. Warner Center for Solar System Studies / MoreData! 446 Sycamore Ave. Eaton, CO 80615 brian@MinorPlanetObserver.com For more theoretical details and discussions, contact Alan Harris MoreData! 4603 Orange Knoll Ave. La Canada, CA 91011 USA harrisaw@att.net 1.2.0 DISCLAIMER ----------------- We have made every attempt to keep the data up to date and correct. However, we know that there is the possibility for omissions or errors. Please let us know of any corrections or additions by sending email to one of the below. Brian D. Warner brian@MinorPlanetObserver.com Alan Harris harrisaw@att.net 2.0.0 DATA FILES -------------------------------------------------------------------------------- The LCDB release consists of 10 primary files (tables) and this file, pds_readme.txt, which provides detailed information about the LCDB and the 10 tables. 2.0.1 AVAILABILITY OF RAW DATA FILES ------------------------------------- The raw databases files are MySQL tables. These are used on the alcdef.org and minorplanet.info web sites for user-defined searches. Starting sometime in 2018, the alcdef.org site will be part of the Small Bodies Node hosted by the University of Maryland. The MySQL tables are not generally available. However, we can - on a limited basis - provide CSV (actually, semi-colon) files generated from the database files that can used with the SQL CLOAD command to populate local MySQL files. Contact the authors detailing the reasons for needing the files. 2.1.0 DISTRIBUTION FILES ------------------------- pds_readme.txt This file of introductory information. lc_ambiguous Lists asteroids with ambiguous periods. lc_binary Lists suspected/confirmed binary/multiple asteroids lc_colorindex Lists color indexes of asteroids (B-V, V-R, V-I, g-r, r-i, B-R). lc_details Lists basic summary table information and the detailed information from individual references. One or more lines per asteroid. lc_diameters Lists summary H, p_V, D values and the same values plus errors from detail records that reported a diameter. lc_notesex Lists extended notes associated with summary and/or details records. lc_npa Lists suspected/confirmed asteroids in non-principal axis rotation (NPAR, or "tumbling"). lc_references Lists all publications referenced in the LCDB. lc_spinaxis Lists asteroids with reported spin axis (poles) and/or shape models. lc_summary Lists summary data, one line per asteroid, no references. 2.1.1 SPIN AXIS CATALOGS ------------------------- As noted above, the lc_spinaxis table stores information about the spin axis properties (ecliptic coordinates and sidereal periods). A more complete and thorough catalog is maintained by Kryszczynska et al. at the Poznan Observatory in Poland. That catalog can be accessed via http://vesta.astro.amu.edu.pl/Science/Asteroids/ Josef Durech (Durech et al., 2010) also maintains a list of spin axis solutions, with shape models and data files. His site is at http://astro.troja.mff.cuni.cz/projects/asteroids3D/ It should be noted that the favored DAMIT pole may differ from the one in the original reference. This is usually because Durech and associates did a new analysis with the original, updated, and/or new data. Their revised result replaced the original instead of indicating a new result under a different reference. Because of the complexities of cross-checking the LCDB vs. DAMIT vs. original result, the LCDB does not directly include any DAMIT results, i.e., there are no entries with DAMIT being the author reference. When and if revised results are published in one of the journals, those results will included in the LCDB. 2.2.0 BINARY ASTEROID FILES ---------------------------- In addition to the lc_binary table, Petr Pravec (Astronomical Institute, Prague, Czech Republic) maintains a considerably more detailed set of files: BINARY_README.TXT Separate README pertaining the binary asteroid BINASTD_PUB.TXT The best estimates of compiled parameters BINASTE_PUB.TXT Uncertainties of the estimates in BINASTD_PUB.TXT BINASTM_PUB.TXT References and notes for the compiled estimates BINASTR_PUB.TXT Information on each of the estimates, e.g., their derivation These files are not included in the PDS release but are are available at http://www.asu.cas.cz/~asteroid/binastdata.htm 2.2.1 ABOUT BINARY DATA ------------------------ The data in the lc_binary table are by no means exhaustive. They are meant to provide a quick overview of the primary period and amplitude as well as a secondary period and/or orbital period and, if available, amplitude. Also included, if available, are the depth (magnitude drop) of mutual events, the Ds/Dp (effective diameter) ratio of satellite to primary, and ADp (semi-major axis to primary diameter ratio). The reader is urged to consult the original journal articles for more complete details. A good summary page with links to those journal references is the web site run by Wm. Robert Johnston http://www.johnstonsarchive.net/astro/asteroidmoons.html 3.0.0 LCDB DATA ------------------------------------------------------------------------------- The original lightcurve database was a simple text file with a structure that tried to minimize disk space requirements. That served well for many years. However, the rapidly growing number of lightcurves being reported as well as the file's format not being able to accommodate some data prompted a change starting in mid-2006. The foremost change was converting to a relational database that included numerous tables and had SQL search capabilities. This allowed for not only easier maintenance of the database but for generating reports in a way that are more informative, complete, and consistent in formatting. The sections below provide the formatting for each field in each table. Of particular importance is to note the -maximum- precision of floating point numbers is not always the actual precision of the reported value. In critical studies, it is important for end-users to keep the original precision of the values. 3.1.0 DIRECT DATA ------------------ Data that are obtained directly from photometric observations includes 1. Rotation period (usually synodic). 2. Amplitude. 3. Absolute magnitude, H, and phase slope parameter, G, when determined by using reduced magnitude versus phase angle data. 4. Binarity due to mutual events, i.e., occultations and eclipses. In such cases, the rotation period of the primary and orbital period of the satellite and the amplitude of the primary lightcurve are the usual direct results. The size ratio can be computed from the depth of the events. For more details on binary lightcurve analysis, see Pravec et al. (2006). 5. Color indices. 6. Diameter if based on stellar occultation or adaptive optics/radar. Radar diameters can also be considered indirect depending on how the diameter was determined. 7. Taxonomic class. 3.1.1 SYNODIC VERSUS SIDEREAL PERIOD ------------------------------------- The synodic period depends on viewing aspect and the rate of motion of the asteroid across the sky. An expression for the magnitude of the expected difference between the sidereal period and synodic period based on the phase angle bisector (PAB; see Harris et al., 1984) is DeltaP = [d(PAB)/dt] * P^2 Where DeltaP difference between synodic and sidereal periods, in units of the rotation period (usually hours). [d(PAB)/dt] angular rate of change in the Phase Angle Bisector in inverse units of the rotation period, e.g., in units of cycles/hour P the synodic rotation period of the asteroid in the same units of time e.g., hours/cycle For example, assume an asteroid with a rotation period of 8 hours observed when the PAB is changing by 0.05 deg/day (typical for a main-belt asteroid at opposition). The sidereal-synodic difference is DeltaP = [0.05 / 360.0 / 24.0] * (8 ^ 2) = 0.00037 hr. cycles / hour hours^2/cycles^2 hours / cycle The synodic-sidereal difference can be either positive or negative, and can exceed the value given by this expression for near-polar aspects, but the expression gives a reasonable estimate of the magnitude of the expected difference. In most cases, the period given in the summary and details lines are synodic and not sidereal. An 'S' flag (see notes below) indicates that the period is sidereal. There are many entries in both tables that do not carry the 'S' flag when they should. This is part of the legacy nature of the data after converting the files to the new data base, i.e., the old format did not allow for indicating the period was one type or another. We hope to update these and other legacy values that now have qualifying flags in future versions. For most studies, the difference between sidereal and synodic period is not significant. 3.1.2 INDIRECT DATA -------------------- Indirect data are those obtained by calculation and/or assumption. 1. Diameter, H, and albedo (p_V, p_R, etc.). The relationship between H, diameter, and albedo is: D = (1329km) * 10.0^(-0.2*H) / sqrt(albedo) or logD (km) = 3.1235 - 0.2H - (0.5 * log(albedo)). (See Pravec and Harris, 2007). The value of H is usually known, though not always accurately, based on photometric observations. If direct data are available for D and/or p_V, then the above relationships can be used to derive a missing quantity. Data from the SIMPS study (Tedesco et al., 2004). NASA Planetary Data System) are used when available and no overriding data are available. If a newer value of H than that used by SIMPS is available, the diameter and albedo are re-computed based on Harris and Harris (1997). If the diameter was based on an assumed albedo and H is revised, the albedo is held constant and the diameter re-computed using the above formulae. If the diameter was determined by radar, resolved imagery, etc. and a new H is available, the diameter is held constant and the albedo is re-computed. As of 2018 March, only 23 summary records used the SIMPS diameter. We acknowledge that several, newer IR surveys (e.g., WISE, AKARI, and Spitzer) have reported diameters. It was an impossible task to weigh the individual results and adopt one for the summary record. Therefore, the SIMPS diameters are still used. However, the lc_details and lc_diameters tables both list all included reported diameters. These allow the user to make his own decision about which diameter is the "true" value. 2. Taxonomic Class, orbital class, and albedo These three values can have a complex relationship when the class and albedo are not directly obtained. When spectroscopic or other data are available that can determine the taxonomic class exactly but no direct albedo data are available, the albedo can be assumed. This albedo can, in turn, be used to find the estimated diameter and/or H if those quantities are not directly known. Flags in the lc_summary table indicate the source of these fields, including if they are assumed based on a combination of available data. The table below shows the assumed values used barring any direct data. The family/group is based on orbital parameters. These are mostly for informational purposes only since the definition for some groups or families is "fuzzy" at best. Note the distinction between a family and group. A family is a set of asteroids with a common parent body. A group is a set of asteroids with common orbital characteristics. Members of a family will almost always be in the same group, but members of a group may not necessarily be of the same family. Here, again, progress has been dramatic since the start of the LCDB, with numerous new families and those within larger families have been identified. The list below, therefore, is only a basic one, listing the more significant families and groups. Group/Family Orbit parameters Class p_V NOTES -------------------------------------------------------------------------------------------------- Baptistina Bottke el al C 0.057 Centaur 5.5 < a <= 30 C 0.057 Centaur Comet Centaur w/comet behavior C 0.057 9 Comet-like orbit Q > 5.0 C 0.057 4 Comet exhibits coma and/or tail C 0.057 Eos 2.99 < a < 3.03, 0.01 < e < 0.13, 8 < i < 12 S 0.14 Erigone 2.32 < a < 2.40, 0.15 < e < 0.22, 4 < i < 6 C 0.057 Eunomia 2.53 < a < 2.72, 0.08 < e < 0.22, 11 < i < 16 S 0.21 Flora 2.15 < a < 2.35, 0.03 < e < 0.23, 1.5 < i < 8 S 0.24 Hungaria 1.78 < a < 2.0, e < 0.18, 16 < i < 34 ES 0.3 1 Karin Nesvorny, private communications S 0.26 Koronis 2.83 < 2.91, e < 0.11, i <= 3.5 S 0.24 Main belt - inner a < 2.6 S 0.20 5 Main belt - inner comet a < 2.6 C 0.057 9 Main belt - middle 2.6 < a < 2.7 SC 0.10 Main belt - middle comet 2.6 < a < 2.7 SC 0.10 9 Main belt - outer 2.7 < a < 5.0 C 0.057 Main belt - outer comet 2.7 < a < 5.0 C 0.057 9 Mars crosser 1.3 < q < 1.668, Q < 5.0 S 0.20 5 NEA (Apollo/Aten/Amor) q < 1.3 S 0.20 5 NEA (comet) q < 1.3 C 0.057 9 Nysa 2.4 < a < 2.5, 0.12 < e < 0.21, 1.3 < i < 4.3 S 0.20 6 Phocaea 2.25 < a < 2.5, e >= 0.1, 18 < i < 32 S 0.23 Planet Satellite 7 Themis 3.08 < a < 3.24, 0.09 < e < 0.25, i <= 3 S 0.08 TNO/KBO a > 30 C 0.1 Trojan - Jupiter 5.05 < a < 5.4 C 0.057 Trojan - Mars similar to Mars S 0.20 5 Trojan - Neptune similar to Neptune C 0.057 Trojan - Saturn similar to Saturn C 0.057 2 Trojan - Uranus similar to Uranus C 0.057 2 Vestoid 2.26 < a < 2.48, 0.03 < e < 0.16, 5 < i < 8.3 S 0.20 3 NOTES ----- 1 p_V = 0.3 is a compromise value when no taxonomic information is available since the Hungarias are both a family (common parent, E/X class, p_V = 0.4) and group (similar orbits, S class, p_V = 0.20). 2 None known and not likely due to perturbations by giant planets, interior and/or exterior. 3 Higher albedo (p_V = 0.4) assigned only if determined to be in V class (SMASS, etc.). Otherwise, class is 'S' and p_V = 0.20 on the presumption that the object shares orbital characteristics but not parent body. 4 Barring any other classification that meets Q > 5, the orbit is classified as "comet-like." 5 The default p_V = 0.20 ± 0.07 for S-type objects was derived from the geometric mean of all S-type objects in the LCDB with known albedos. 6 The Nysa orbital space is polluted by a large portion of objects that are not true members of the Nysa-Hertha family and, even then, the true members are heterogeneous in nature. For this reason, we elected to treat the Nysa space the same as other unassociated inner main belt objects by using a default of S class and p_V = 0.20. 7 The planet satellite group includes small and distant natural satellites of the major planets, e.g., Himalia Jupiter VI. They are included since a number of these smaller bodies resemble asteroids in size and rotational properties. 9 Several orbital groups have been given a "comet" subclass. This is for objects within the given orbital class that have shown cometary activity, e.g., so-called "main belt comets." The Comet class is reserved for "true" comets, e.g., P/Encke and the Comet-like orbit class is still reserved for objects that have very elongated orbits but have shown no signs of cometary activity. These "comet" subclasses are given default taxonomic class of 'C' and albedo of p_V = 0.057. 3. Color Index applied to H Color index is not generally assumed or entered into the LCDB. However, sometimes the value of H was found in a photometric band other than V, e.g., Cousins R. In that case, and if the value is used to override the H given by SIMPS or the MPCORB table (Minor Planet Center) in the summary record, H is transformed to the V band. When the color index is not directly available, these values are used to transform the measured H value: V-R 0.45 B-V 0.80 V-r' 0.23 When such a transform is used in the summary record, whether or not based on an assumed value, the H value has the 'T' (transformed) flag. 3.2.0 ORPHAN RECORDS --------------------- The full summary (MySQL) table contains almost 300,000 "orphaned" records. These are where no lightcurve observations have been reported but other data stored in the details and/or other tables in the LCDB have, e.g., diameters, color index, taxonomic class, etc. These records, and any details records associated with the object, are -not- considered when creating the lc_summary and lc_details tables. However, the orphan flag ('O') -is ignored- when generating the other tables so that the non-lightcurve data can still be made available. See also section 6.0.1 4.0.0 LCDB FILE DESCRIPTIONS -------------------------------------------------------------------------------- The following sections describe the specific tables that are part of the LCDB release. A column map is provided for each table that shows the type and format of each field. N.B. Again, the format indicates the -maximum- precision allowed in data entry but -not- necessarily the original precision. The latter which is retained during LCDB data entry. Sub-sections describe the meaning of the flags that qualify various fields in each table. The use of these maps will allow creating custom tables that are more user- friendly than CSV files. 4.1.0 LC_SUMMMARY AND LC_DETAILS TABLES ---------------------------------------- These are the primary tables in the LCDB release. They show both direct and indirect data, the most important being the direct data of lightcurve period and amplitude, along with our assessment of the quality of the period solution. The latter is expressed by the U code, which is described in detail below. The lc_summary table uses one line per object, which includes the full summary listing for the asteroid. This line represents our best determination of the primary information for the given object based on the data in the details table. For example, where several periods are available, the summary line gives the one that we consider the most likely to be correct. Sometimes that value may be an average of the available values. In the lc_details table, each line includes core summary information followed by the details record data. There can be multiple lines per asteroid. Each line includes, when available, not only the reported value but the reported error. Also included is the "Short Reference" that can be used to find the full citation for the original publication in the lc_references table. 4.1.1 MULTIPLE DETAILS TABLE ENTRIES ------------------------------------- In some cases, there is more than one detail line under a given asteroid with the same publication reference. This is deliberate in order to allow statistical studies of lightcurve amplitude versus phase versus class (albedo). For example, if a single publication reports the lightcurve behavior for an asteroid where the synodic period and/or amplitude of the curve changed significantly during the course of the observations, the lc_details table will include an appropriate number of entries. Those entries will "split out" the results so that the period and/or amplitude can be tied to a specific (though maybe only approximate) set of PAB or Phase values. A good example would be a paper reporting observations of an NEA asteroid over several weeks where the amplitude of the curve when from 1.1 to 0.3 magnitudes over the range of observations. In most cases, splitting the results into distinct sets was not difficult, e.g., the asteroid was observed on one night at one-week intervals. In some cases, the split was not so distinct. In this case, compromises were made in order to avoid having an excess of multiple entries while still retaining sufficient resolution of the variations versus time. A variation on the above is if the author(s) forced the data from several blocks of dates to fit a fixed period solution. Here, the period will be the same for all entries, though the amplitude may change. In this case, the period is left blank for the second and subsequent lines. The U code is assigned for each lightcurve based on the presumption that the fixed period is correct, i.e., it is based on the quality of the fit of the data to the presumed period. The main point of interest is the amplitude for the reasons given above. Other information that was derived based on the given block of data, e.g., a value for H, G, or a color index, will be included within that details record as well so that it's clear which block of data was used to derive the given values. 4.1.2 U (QUALITY) CODE ----------------------- The U code provides our assessment of the quality of the period solution, not necessarily of the data per se. The uniqueness of the solution, while an important factor, is not the sole consideration in making an assessment. The quality of the data is sometimes used as a tie-breaker when deciding between two half-steps, e.g., between 2+ and 3-. Depending on the specifics for a given asteroid, a good period solution can be obtained by using a large amount of lesser quality data about as well as using less data that is of higher quality. Many factors come into play making the assessment. The table below gives the general outline of the criteria used, going from highest to lowest rating. 3 The lightcurve is completely unambiguous in terms of period, i.e., there are no cycle ambiguities or possible solutions with single, triple, or other number of extrema. The coverage of the entire rotation phase is to the degree than any remaining small gaps can be confidently interpolated. 3- A unique period determination, but possibly some moderate gaps in coverage, enough so that interpolation of the entire curve is not certain, but not enough to allow any other solution. 2+ It is unlikely but not impossible that the period is in error due to cycle counts or alternate numbers of extrema per cycle, and no more than moderate gaps in coverage (as in U = 3-). Another case is if there are indications that a second period (e.g., due to a satellite) might have been overlooked. These can manifest themselves as one or two nights where the data showed an unexpected attenuation compared to the rest of the lightcurve. 2 Result based on less than full coverage, so that the period may be wrong by 30 percent or so OR to note results where an ambiguity exists as to the number of extrema per cycle or the number of elapsed cycles between lightcurves. Hence the result may be wrong by an integer ratio. 2- Period and total amplitude not firmly established. For example, a single night coverage of about half a cycle including a maximum and minimum, but not enough to actually derive an accurate period. This is the minimum reliability code that we accept for statistical analysis. 1+ Similar to U = 2-, but with less amplitude so that it is not absolutely certain that the variations are true rotational variation and not due to noise, etc. 1 May be completely wrong. What is interpreted as rotational variation may be just noise, calibration error, etc. 1- Probably wrong. A lightcurve that may be completely wrong (as in U = 1) but, in addition, the claimed period is very unlikely, e.g., a large object with a claim of P < 2h. 0 Result later proven incorrect. This appears only in detail table entries, not the summary table. It is important to keep in mind that U = 0 does not necessarily mean that the data for a given lightcurve are of low quality. The only interpretation that should be inferred is that the -reported solution- has been determined, perhaps from subsequent data, to be incorrect so that not even the loose constraints of U = 1 or U = 2 can be used. For the most part, U = 0 will be used very sparingly and the previous U rating (unless 3) will be retained to avoid the false impression that the data are of limited or no use. N.B. Until the intermediate release in 2008 November, the LCDB also used a value of '4' for the U code, which indicated that a pole solution had been reported. This is no longer the case since, in the past, there have been cases where a 4 was assigned because there was a pole solution given but the best available period solution was no better than 2. The period solution quality is now independent of any pole solution. A separate "Pole" flag in the summary and details tables is used to indicate that a pole solution has been reported. The lc_spinaxis table includes more details and its own quality code assignment. Assignment of the refined ratings using a + or - is a work in progress as we catch up with almost 30 years of data entry. Therefore, not all U code ratings will match what we would give under current rules and are subject to change. Some details lines, and even some summary, may not contain a U code rating. this is deliberate and can be for several reasons. 1. The available data do not include a lightcurve, therefore, it is not possible to give a rating to the curve. In some cases, where the results are reported by observers whose standard of work is known to be of sufficient quality, we may assign an interim U code, usually 2, until a lightcurve or the data are available. 2. In the case where several results are published for a given object in the same reference, we will assign a U code rating for the "best" available data and include only new information for that given Details record, e.g., see section 4.1.1, "Multiple Details Table Entries." 3. When the available data do not reasonably define a period or even constrain a range in which the period lies. In addition, the data may not provide any reasonable indication of the amplitude. The details table entry will have only the reference to the work; the period, amplitude, and U code rating will use the default "no data" entries. The summary line may also have no period and/or amplitude as well as no U code. This occurs when none of the detail records, even if they have some or all of the information, is deemed insufficiently reliable to put in the summary line. This is done to show that there are data available for the object but that they may be of limited use. 4.1.3 LC_SUMMARY COLUMN MAP ---------------------------- LC_SUMMARY ---------- The column positions assume a 1-space delimiter between columns. See the notes after the lc_details column map regarding the flags used to indicate the source/method used for certain values Field Format Pos Notes ------------------------------------------------------------------------------------- Number I7 1-7 MPC-assigned number; empty if no number assigned Name A30 9-38 MPC-assigned name, or designation if not named Desig A20 40-59 MPC primary designation, if assigned Family A5 61-65 The orbital group or collisional family CSource A1 67 Flag indicating source for taxonomic classification Class A5 69-73 The taxonomic class DiamSource A1 75 Flag indicating the source for the diameter DiamFlag A1 77 Flag (e.g., < or >) that qualifies the diameter Diam F8.3 78-85 Adopted Diameter (km) HSource A1 87 Flag indicating the source of the H value H F6.3 89-94 Adopted absolute magnitude H HBand A2 96-97 The photometric band of H GSource A1 99 Flag indicating the source of the G value G F6.3 101-106 Adopted phase slope parameter (G or G12; see notes) AlbSource A1 108 Flag indicating the source of the albedo value AlbFlag A1 110 Flag (e.g., < or >) qualifying the albedo value Albedo F6.4 112-117 Adopted Albedo (same band as H) PFlag A1 119 Period qualifier Period F13.8 121-133 Rotation period, in hours; usually synodic PDescrip A15 135-149 Description of period if PFlag = 'D'; e.g., "long" AmpFlag A1 151 Amplitude flag, e.g., > or < AmpMin F4.2 153-156 Minimum reported amplitude AmpMax F4.2 158-161 Maximum reported amplitude U A2 163-164 Lightcurve Quality Notes A5 166-170 Qualifying flags for record Pole A1 172 Y/N Y = Pole position reported in spin axis table IsBinary A1 174 ? = Suspected; B = Binary; M = Multiple; blank if none WideField A1 176 Y/N Y = Results based on wide-field survey SparseData A1 178 Y/N Y = Results based on sparse data survey NotesEx A1 180 Y/N Y = Entry in lc_notesex table Private A1 182 Y/N Y = Private record. The results have been supplied for the LCDB authors' use only; the only entries will be the number/name/desig and U code, if there is one. The Min/Max Amplitude values are based only on detail lines that have a U >= 2- ratings. If the U code is empty or U <= 1+, the detail line min/max amplitudes are not considered. LC_DETAILS ---------- Field Format Pos Notes ------------------------------------------------------------------------------------- Number I7 1-7 MPC-assigned number; empty if no number assigned Name A30 9-38 MPC-assigned name, or designation if not named SumPer F13.8 61-73 Period from summary table, hours SumAmp F4.2 75-79 AmpMax from summary table ShortRef A30 81-110 Short Reference from lc_references table WorkedAs A20 112-131 The name or designation at the time of the observations DateObs A10 133-142 Approximate date (yyyy-mm-dd, 0h UT) of mid-observations PABL F5.1 144-148 Phase angle bisector longitude at DateObs PABB F5.1 150-154 Phase angle bisector latitude at DateObs Phase F5.1 156-160 Solar phase angle at DateObs (always positive) Family A5 162-166 Orbital group/collisional family, if reported Class A5 168-172 Taxonomic class, if reported DiamMeth A1 174 Method used to find reported diameter, if any Diam F8.3 176-183 Diameter (km), if reported DiamErr F8.3 185-192 Error in Diam (km), if reported HMeth A1 194 Method used to find H, if reported H F6.3 196-201 Absolute magnitude (H), if reported HErr F6.3 203-208 Error in H, if reported HBand A2 210-211 Color band for H (see notes) GSource A1 213 Method used to find reported G, if any G F6.3 215-220 Phase slope parameter (G or G12), if reported GErr F6.3 222-227 Error in G, if reported AlbSource A1 229 Method to find albedo, if reported AlbFlag A1 231 Flag qualifying albedo value, e.g., < or > Albedo F6.4 233-238 Albedo, if reported (same band as H, if reported) AlbErr F6.4 240-245 Error in albedo, if reported PFlag A1 247 Period qualifier Period F13.8 249-261 Rotation period, hours; usually synodic PerErr F10.8 263-272 Error in period, hours PDescrip A15 274-288 Description of period if PFlag = 'D'; e.g., "long" AmpFlag A1 290 Amplitude qualifier, e.g., > or < AmpMin F4.2 292-295 Minimum amplitude, if reported AmpMax F4.2 296-299 Maximum amplitude, if reported AmpErr F4.2 301-304 Error in AmpMax, if reported U A2 306-307 Lightcurve Quality Notes A5 309-313 Qualifying flags for record Pole A1 315 Y/N Y = Pole position reported in spin axis table IsBinary A1 317 ? = Suspected; B = Binary; M = Multiple; blank if none WideField A1 319 Y/N Y = Results based on wide-field survey SparseData A1 321 Y/N Y = Results based on sparse data survey NotesEx A1 323 Y/N Y = Entry in lc_notesex table Private A1 325 Y/N Y = Private record. The results have been supplied for the LCDB authors' use only; the only entry will be the number/name/desig and U code, if there is one. NOTES: ------------------------------------------------------------------------------- The values for H, G, Diameter, and albedo may have been measured, calculated (e.g., Diameter from H and albedo), or assumed. For IR surveys, e.g., WISE, the H value was often assumed based on the value from the MPCORB table or some other source. Another possible case is a value for H determined using an assumed value for G. See Warner et al. (2009) for a more detailed explanation of the source/method flags. Taxonomic Class Source/Method Flags ----------------------------------- A Assumed based on orbital group L Taken from a details table entry S SMASS (Bus and Binzel, 2002a; 2002b) T Tholen (1984) H Method/Source Flags --------------------- A From Lowell ASTORB table D Derived from diameter and albedo E Estimated L Taken from a details table entry M From MPCORB table S From SIMPS (Tedesco et al., 2004) T Transformed (Usually a details entry converted from H_R to H_V) W From WISE (Mainzer et al., 2011) H Color Band ------------ This indicates the color band in which the value for H was found Blank Johnson V B Johnson B V Johnson V R Cousins R I Cousins I SU Sloan u' SG Sloan g' SR Sloan r' SI Sloan i' SZ Sloan z' G Method/Source Flags --------------------- A From Lowell ASTORB table D Default for taxonomic class (see Warner et al., 2009) G Based on H-G12 system L From an entry in the details table M From the MPCORB table P From Pan-STARRS (Veres et al., 2015) W From WISE (Mainzer et al., 2011) Diameter Qualifier Flags ------------------------ < Diameter is a maximum > Diameter is a minimum Diameter Method/Source Flags ---------------------------- C Calculated from albedo and H D Derived from albedo and H (after using Harris and Harris, 1997) K From AKARI (Usui et al., 2011) L Taken from a details table entry S From SIMPS (Tedesco et al., 2004) T Thermal (determined from IR observations) W From WISE (Mainzer et al., 2011) Albedo Method/Source Flags -------------------------- A Assumed (based on orbital group or taxonomic type) D Derived from H and diameter K From Akari (Usui et al., 2011) L From a details table entry S From SIMPS (Tedesco et al., 2004) W From WISE (Mainzer et al., 2011) Period Flags ------------ < Period is a maximum value > Period is a minimum value D Indeterminate period described in the PDescrip field S Period is sidereal (default is synodic) 4.1.4 FIELD (FLAG) CODES USED IN SUMMARY AND DETAIL LINES ---------------------------------------------------------- The flags appear in the data field immediately before the value they qualify. In most cases, they are a single character. AMPFLAG (Amplitude Flag) ------------------------ Blank NONE < Less than > Greater than PFLAG (Period Flag) ------------------- Blank NONE < Less than > Greater than D No numerical value, see P DESC field description S Sidereal period, default is no flag and synodic period U Uncertain, not the same as ambiguous where one or additional periods are reported. For example, the data did not allow finding a definite period and so the author(s) reported a "best guess." NOTES (single letter flag(s)) ----------------------------- Blank NONE ? Usually tied with 'T' or 'A' flags to indicate uncertainty - Tied with T flag. See notes below. X is an integer, e.g., 3 for a trimodal curve (three min/max per rotation) or 4 quadramodal curve (four min/max per rotation), etc. A Ambiguous period (see lc_ambiguous table for details) D Period determined by us that differs from that given in the original publication E Occultation observation (usually when reporting a diameter) H Space telescope observations (optical) I IR/Thermal observations (e.g., Spitzer) M Polarimetric observation N No lightcurve published O Adaptive optics observation P Photographic photometry R Radar observation S Spectroscopic T Tumbling (NPA rotation - see lc_npa table for details and notes below) V Visual photometry The 'A' and 'T' notes flags are used to call the reader's attention to the lc_ambiguous or lc_npa tables, respectively. They should not be taken as stand-alone information. Instead, consider them footnote numbers in the body of a main text. The other reports (and original references) are the actual footnotes. The A flag does not appear in the summary line unless the summary line value itself represents an ambiguous solution, i.e., just because a details line may report an ambiguous period does not mean that the summary period is also ambiguous. The T flag currently has four possible qualifiers: Blank The asteroid has a PAR < -1, i.e., it is definitely tumbling. Example: T ? Possible tumbler. There is some evidence that the asteroid might be a tumbler. It may carry a PAR = 0 to -1. See the discussion for the lc_npa table for the meaning of the PAR codes. Example: T? 0 The tumbling damping time scale (see Pravec et al, 2005) is long enough that tumbling might be expected, but observations are not sufficient to substantiate either tumbling or not tumbling, PAR = 0. Example: T0 - The tumbling damping time scale is long enough that tumbling might be expected, but observations indicate that the object is NOT tumbling, i.e., PAR >= 1. Example: T- + The tumbling damping time scale is short enough that tumbling would not seem likely, however observations indicate that it may be tumbling or actually is tumbling. PAR = < 0. Example: T+ We include the expanded tumbling notes to call attention to what we consider to be an important aspect in the study of YORP spin up/down theories. This is done by making known any asteroids that are or are strongly believed to be tumbling as well as those that should be and aren't or are and shouldn't be. The W flag is included so that those doing statistical studies can include or exclude the results from these surveys. Such surveys can introduce significant biases by "cherry picking" the best results from a large pool and so skew overall rotational statistics. See the paper by Warner and Harris (2011, Icarus). 4.1.5 DATA SUITABLE FOR ROTATION RATE STUDIES ---------------------------------------------- As noted in Warner et al. (2009), only those objects with a U code of 2- or greater in the lc_summary table, i.e., U = 2-, 2, 2+, 3-, or 3, should be used for rotational rate studies and, unless there is a specific reason otherwise, the summary line period should be used instead of one of the periods in the details table. 4.2.0 LC_AMBIGUOUS (AMBIGUOUS PERIODS) -------------------------------------------------------------------------------- This table includes any record where the notes flag in a summary and/or detail record indicates an ambiguous period. There is not always a direct cross-connection between the summary and details entries. For example, it's possible to have a summary line without the ambiguous period flag but one or more of the Details lines to have the flag. In this case, we judge that the ambiguity has been resolved by subsequent observations, but retain the ambiguous flag in the detail line for historical accuracy. In turn, if the summary line is flagged as ambiguous, this does not mean that any of the details lines are also flagged as such. In that case, it means that no one solution sufficiently stands out and so the one that is reported on the summary line is considered to be only the most probable solution. The first line for a given object is the Summary line, which contains the number and name of the object and the adopted period and amplitude. As noted above, the details lines(s) may not agree with the summary line. 4.2.1 LC_AMBIGUOUS COLUMN MAPPING -------------------------------------- Field Format Pos Notes -------------------------------------------------------------------------------- Number I7 1-7 MPC-assigned number; empty if no number assigned Name A30 9-38 MPC-assigned name, or designation if not named SumPer F13.8 61-73 Period from summary table, hours SumAmp F4.2 75-79 AmpMax from summary table SumNotes A5 81-85 Qualifying flags for the summary record DetNotes A5 87-91 Qualifying flags for the details record ShortRef A30 93-122 Short Reference from lc_references table DateObs A10 124-133 Approximate date (yyyy-mm-dd, 0h UT) of mid-observations Period1 F13.8 135-147 Preferred period, hours, from details record Period1Err F13.8 149-161 Error in preferred period, if reported Amp1 F4.2 163-166 Preferred amplitude from details record Amp1Err F4.2 168-171 Error in amplitude, if reported Period2 F13.8 173-185 First alternate period, hours Period2Err F13.8 187-199 Error in period, if reported Amp2 F4.2 201-204 First alternate amplitude Amp2Err F4.2 206-209 Error in amplitude, if reported Period3 F13.8 211-223 Second alternate period, hours Period3Err F13.8 225-237 Error in period, if reported Amp3 F4.2 239-242 Second alternate amplitude Amp3Err F4.2 244-247 Error in amplitude, if reported Period4 F13.8 249-261 Third alternate period, hours Period4Err F13.8 263-275 Error in period, if reported Amp4 F4.2 277-280 Third alternate amplitude Amp4Err F4.2 282-285 Error in amplitude, if reported 4.3.0 LC_BINARY (BINARY/MULTIPLE ASTEROIDS) -------------------------------------------------------------------------------- This table includes those asteroids that are known or suspected binaries. This is not meant to be a comprehensive compilation of data for binary asteroids. Visit the URL given in section 2.2.0 for a page that provides more details as well as links to the original journal articles. Each line indicates the type of binary. There are four broad categories: Fully-asynchronous (Binary Type Flag: A) Example: 1509 Esclangona The satellite's rotation period is different from its orbital period. In this case, the orbital period is given along with the independent rotation period and lightcurve amplitude of the satellite, if available. Singly-asynchronous (Binary Type Flag: S) Example: 5905 Johnson The satellite's rotation period and orbital period are the same, i.e., they are tidally-locked, but different from the primary's spin period. In this case, only an orbital period is given. The lightcurve may be flat or bowed between events. If flat, the presumption is that the satellite is nearly spheroidal and the rotation is still tidally-locked to the orbit. If the lightcurve shows an overall "bowed" shaped, this is presumed to indicate a significantly elongated satellite. Fully-synchronous (Binary Type Flag: F) Example: Pluto/Charon, 90 Antiope The rotation period of the primary and satellite are the same and is the same as the orbital period of the satellite. In this case, the primary rotation period and lightcurve amplitude is given and matches the orbital period of the two bodies. No secondary period is given. Undetermined (Binary Type Flag: U) Usually reserved for binaries discovered by imaging with Hubble or very large ground-based telescopes. In most cases, the orbital parameters are not or very poorly known and there are no lightcurves to determine the actual type of binary, e.g., if the satellite is tidally locked to its orbital period. In some asynchronous systems, it is not always possible to determine with certainty which of the two periods is due to the primary and which is due to secondary. In these cases, we are forced to give the period and amplitude of one body as that of the "primary" and the other period and amplitude as that of the "secondary" when, in fact, the roles may be reversed from our selection. For multiple systems and in _most_ cases, the satellite information is for the first one discovered. In some cases, e.g., 3749 Balam, the first discovery was for a satellite with a long orbital period of 1920 hours. It is assumed that the satellite's rotation is not equal to the orbital period. A second satellite was found that has a rotation period that is tidally-locked to its orbital period of about 33.4 hours. Each line also gives the primary rotation period and amplitude and secondary/orbital periods/amplitudes as appropriate. If available the estimated effective diameter ratio (Ds/Dp) is given, as are the ratio of the semi-major axis of the satellite orbit to the diameter of the primary (A/Dp). The Ds/Dp ratio is a minimum in most cases since total eclipses were not seen in the satellite's lightcurve. The DsDpFlag qualifies this value, e.g., < or >. If there is no flag and there is a Ds/Dp value, assume '='. 4.3.1 SECONDARY VS. ORBITAL PERIOD ----------------------------------- In some cases, there is only a secondary period ("SecPer") given; in others, only an orbital period ("OrbPer"); and in others, both periods are given. The case when "PerOrb" is given is usually the result of timing of mutual events (occultations and/or eclipses) and so there will be at least an "EventMax" value given. When only "SecPer" is reported, then the lightcurve was defined by two periods, with the second period attributed to the rotation of a satellite but the viewing geometry did not allow mutual events. The second period might also be due to low-level tumbling. Regardless, without mutual events or other definitive confirmation, the asteroid will likely be classified as "suspected" and not confirmed. When both periods are reported, then the secondary period is likely due to the presence of a third body in the system. Unless separate mutual events or other definitive evidence is provided, they system will be classified as "binary" and not "multiple." 4.3.2 LC_BINARY COLUMN MAPPING ----------------------------------- Field Format Pos Notes --------------------------------------------------------------------------------- Number I7 1-7 MPC-assigned number; empty if no number assigned Name A30 9-38 MPC-assigned name, or designation if not named SumBin A1 40 ? = suspected; B = binary; M = multiple SumPer F13.8 42-54 Period from summary table, hours SumAmp F4.2 56-59 AmpMax from summary table ShortRef A30 61-90 Short reference from lc_references table DateObs A10 92-101 Approximate mid-date (yyyy-mm-dd, 0h UT) of the observations DetBin A1 103 ? = suspected; B = binary; M = multiple BinType A1 105 A = fully-asynchronous; S = singly-asynchronous; F = fully-synchronous PrimPer F13.8 107-119 Rotation period of the primary, hours PrimPerErr F13.8 121-133 Error in period, if reported PrimAmp F4.2 135-138 Maximum amplitude of the primary lightcurve PrimAmpErr F4.2 140-143 Error in primary amplitude, if reported SecPer F13.8 145-157 Secondary period (see section above) SecPerErr F13.8 159-171 Error in secondary period, if reported SecAmp F4.2 173-176 Amplitude of secondary period lightcurve SecAmpErr F4.2 178-181 Error in amplitude, if reported OrbPer F13.8 183-195 Orbital period of the first satellite, hours OrbPerErr F13.8 197-209 Error in period, if reported EventMin F4.2 211-214 Shallowest amplitude of the mutual events EventMax F4.2 216-219 Deepest amplitude of the mutual events DsDpFlag A1 221 Qualifier for Ds/Dp, e.g., < or > DsDp F4.2 223-226 Ratio of first satellite/primary effective diameters DsDpErr F4.2 228-231 Error in Ds/Dp value ADp F5.2 233-237 Ratio of first satellite orbital semi-major axis to primary diameter ADpErr F5.2 239-243 Error in Ds/Dp ratio 4.4.0 LC_COLORINDEX COLUMN MAPPING ----------------------------------- Unless the lc_notesex table indicates otherwise, the bands are on the Johnson- Cousins BVRI and Sloan griz systems. 4.4.1 LC_COLORINDEX COLUMN MAPPING ----------------------------------- Field Format Pos Notes --------------------------------------------------------------------------------- Number I7 1-7 MPC-assigned number; empty if no number assigned Name A30 9-38 MPC-assigned name, or designation if not named SumPer F13.8 40-52 Rotation period from summary table, hours SumAmp F4.2 54-57 AmpMax from summary table ShortRef A30 59-88 Short reference from the lc_references table DateObs A10 90-99 Approximate mid-date (yyyy-mm-dd, 0h UT) of the observations DetPer F13.8 101-113 Rotation period from details record, if reported; hours DetPerErr F13.8 115-127 Error in rotation period, hours DetAmp F4.2 129-132 Lightcurve amplitude, if reported DetAmpErr F4.2 134-137 Error in amplitude BV F6.3 139-144 B-V color index BVErr F6.3 146-151 B-V error BR F6.3 153-158 B-R color index BRErr F6.3 160-165 B-R error VR F6.3 167-172 V-R color index VRErr F6.3 174-179 V-R error VI F6.3 181-186 V-I color index VIErr F6.3 188-193 V-I error SGR F6.3 195-200 g-r color index SGRErr F6.3 202-207 g-r error SRI F6.3 209-214 r-i color index SRIErr F6.3 216-221 r-i error SIZ F6.3 223-228 i-z color index SIZErr F6.3 230-235 i-z error 4.5.0 LC_DIAMETERS ------------------- This table is provided for those wanting to quickly dissect and compare diameters reported in the summary and details tables. It includes "orphaned" summary records (see Section 3.2.0/6.0.1, "ORPHAN RECORDS"). 4.5.1 LC_DIAMETERS COLUMN MAPPING ---------------------------------- Field Format Pos Notes --------------------------------------------------------------------------------- Number I7 1-7 MPC-assigned number; empty if no number assigned Name A30 9-38 MPC-assigned name, or designation if not named SumPer F13.8 40-52 Rotation period from summary table, hours SHBand A2 54-55 Photometric band for H from the summary record SumH F6.3 57-62 Absolute magnitude (H) from summary record SumG F6.3 64-69 Phase slope parameter (G) from summary record SumPv F6.4 71-76 Albedo from summary record SumDiam F8.3 78-85 Diameter (km) from the summary record SumNotes A5 87-91 Qualifying flags for the summary record (See Notes section after lc_details) ShortRef A30 93-122 Short reference from lc_references table DateObs A10 124-133 Approximate mid-date (yyyy-mm-dd, 0h UT) of observations DetPer F13.8 135-147 Rotation period from details record, hours DetPerErr F13.8 149-161 Error in rotation period DetHSource A1 163 Flag indicate method used to find reported diameter DHBand A2 165-166 Photometric band of H DetH F6.3 168-173 Absolute magnitude (H) from details record DetHErr F6.3 175-180 Error in H DetGSource A1 182 Flag indicating method use to find reported G DetG F6.3 184-189 Phase slope parameter (G or G12) from details record GetGErr F6.3 191-196 Error in G DetPv F6.4 198-203 Albedo from details record, same band as H DetPvErr F6.4 205-210 Error in albedo DetDiam F8.3 212-219 Diameter (km) from details record DetDiamErr F8.3 221-228 Error in diameter DetNotes A5 230-234 Qualifying flags for the details record (See Notes section after lc_details) 4.6.0 LC_NOTESEX ----------------- The lc_notesex table contains extended "free-form" notes for summary and/or details records. These entries allow expanded information that cannot be given by a simple, single-character flag. In some cases, only the summary record has an extended note for an object. In this case, the output line will include the summary information given in the column mapping but the rest of the fields will have the default entry. If there is no summary extended note for a given asteroid but one or more details records with notes, then - for each detail record - the summary number and name are included, the summary notes field uses the default , and the data for the given detail record are given. If there are both summary and details extended notes, then the first line includes only the summary extended note and uses the default for the rest of the line. Subsequent lines for the asteroid do not include the summary note but do include the detail record note. In short, no line will contain BOTH a summary and detail extended note. The summary and details table NotesEx fields are defined as varchar(1024) in their MySQL tables. In practice, however, the longest entries is < 128 characters. Even so, keep in mind that a full-length line could exceed 1100 characters. 4.6.1 LC_NOTESEX COLUMN MAPPING -------------------------------- The column mapping below allows for the maximum length of each field. In practice, a delimited (e.g., comma or semi-colon) file with one record per line will be much shorter than the maximum length. The maps below do not account for the flags, usually '-' for a string value and -99 for the Number field if the asteroid is not numbered. For a summary note only record, the fields after "SumNotesEx" would use the value. For details note only record, the "Number" and "Name" fields would have values but the "SumNotesEx" field would use the value. WITH SUMMARY EXTENDED NOTE -------------------------- Field Format Pos Notes --------------------------------------------------------------------------------- Number I7 1-7 MPC-assigned number; empty if no number assigned Name A30 9-38 MPC-assigned name, or designation if not named SumNotesEx A1024 40-1063 Extended note for summary record WITH DETAIL EXTENDED NOTE ------------------------- Field Format Pos Notes --------------------------------------------------------------------------------- Number I7 1-7 MPC-assigned number; empty if no number assigned Name A30 9-38 MPC-assigned name, or designation if not named WorkedAs A20 40-59 The name or designation used by the original authors. This may or may not be the same as the current MPC- assigned name and/or designation ShortRef A30 61-90 The short reference in the publications table DetNotesEx A1024 92-1115 Extended note for detail record 4.7.0 LC_NPA (NON-PRINCIPAL AXIS ROTATION - TUMBLING) --------------------------------------------------------------- This table not just confirmed tumbling asteroids but those that are suspected, those that "should be" tumbling but apparently are not, and those that are tumbling that "should not be" tumbling. In the table, the first period (DetPeriod) is usually the dominant one. Whether or not it is the period of rotation or precession cannot often be established. 4.7.1 PAR RATING ---------------- The PAR rating is adopted from Pravec et al. (2005). See also Pravec et al. (2010), in which a revised set of damping times is developed. These so-called "short" damping times are several times shorter than in the original paper and are preferred. Following is a brief description of the PAR codes. See the Pravec paper for a more detailed explanation. -4 Physical model of the NPA rotation constructed -3 NPA rotation reliably detected with the two periods resolved. There may be some ambiguities in one or both periods. -2 NPA rotation detected based on deviations from a single period but the second period is not resolved. -1 NPA rotation possible, i.e., deviations from a single period are seen, but not conclusively. 0 Insufficient data to determine if rotation is PA or NPA +1 PA rotation is consistent with the data but coverage is insufficient. +2 PA rotation likely, or deviations from PA are small with some overlapping data fitting a PA rotation period. +3 PA rotation quite likely +4 PA spin vector obtained. Entries with a positive number are rare and used when the asteroid was thought to be tumbling but further examination showed it was likely in PA rotation, or when the damping time to PA rotation is sufficiently long that the given asteroid would more likely be in NPA than PA rotation. 4.7.2 LC_NPA COLUMN MAPPING -------------------------------- Field Format Pos Notes -------------------------------------------------------------------------------- Number I7 1-7 MPC-assigned number; empty if no number assigned Name A30 9-38 MPC-assigned name, or designation if not named SumPer F13.8 40-52 Rotation period from summary record, hours SumAmp F4.2 54-57 Maximum lightcurve amplitude from the summary record SumNotes A5 59-63 Qualifying flags for the summary record (See Notes section after lc_details) ShortRef A30 65-94 Short reference from the lc_references table DateObs A10 96-105 Approximate mid-date (yyyy-mm-dd, 0h UT) of observations DetPeriod F13.8 107-119 First (dominant) period from the details record, hours DetPerErr F13.8 121-133 Error in period DetAmp F4.2 135-138 Amplitude associated with first period DetAmpErr F4.2 140-143 Error in amplitude DetPer2 F13.8 145-157 Second period, either precession or rotation, hours DetPer2Err F13.8 159-171 Error in second period DetAmp2 F4.2 173-176 Amplitude associated with second period, rarely reported DetAmp2Err F4.2 178-181 Error in amplitude PAR A2 183-184 PAR rating under Pravec et al. system DetNotes A5 186-190 Qualifying flags for the details record (See Notes section after lc_details) 4.8.0 LC_REFERENCES (REFERENCES/PUBLICATIONS) ----------------------------------------------- The LC_REFERENCES table contains the Bibcode, short reference, and literature citation for each reference in the other data tables. The literature citation limits the number of authors to five. If there are more than five, the fifth "author" is "et al." In recent years, some journals stopped using page numbers but article ids. These are shown as "Axx" with xx being the article id. Where page numbers are given, both starting and ending numbers are given. As is customary, if there is only one publication for a given author in a given year, the short reference does not include a letter after the year, e.g., Warner (2018). If there is more than one publication, then the entries are appended with 'a' through 'z'. So far, it has not been necessary to devise a method for someone having more than 26 publications in a single year. Some short references are appended with 'web', e.g., Warner (2018web). This indicates the results were posted on a web site, hopefully in anticipation of publication in a permanent journal. This also prevents a conflict should an author publish at least 23 papers ('w') -and- also posted pending results on a web site. Current Bibcodes are 19 characters long. The field allows one more character should expansion be required in the future. For the time being, the current table does -not- pad the Bibcode to 20 characters. The Citation field allows up to 255 characters. However, since the LCDB limits the list to five authors, the likelihood of this field exceeding 80 characters is very small. 4.8.1 LC_REF COLUMN MAPPING ---------------------------- Field Format Pos Notes -------------------------------------------------------------------------------- BibCode A20 1-19 19-character BibCode ShortRef A30 21-50 Primary author and year, e.g., Warner (2018a) Citation A255 52-306 Literature citation N.B. Initials for names are packed, e.g., Warner, B.D. and not Warner, B. D. 4.9.0 LC_SPINAXIS (POLE SOLUTIONS) -------------------------------------------- This table includes any asteroid for which spin axis information has been reported. See section 2.1.1, "Spin Axis Catalogs" for additional resources and references. The table lists up to four pole solutions. This allows for the known issues with lightcurve inversion, especially when the object has a low orbital inclination. Generally, it's not uncommon to have two solutions that differ by 180° in longitude but have nearly the same latitude. However, there are other cases where the latitudes are mirrored about the equator and the longitudes are similar. There is also the possibility that both longitude and latitude are mirrored, thus having four possible solutions. 4.9.1 Q (QUALITY) RATING ------------------------- The Q value gives our assessment of the quality of the pole solution. It is adopted from the rating system used in Kryszczynska et al. (2007, Icarus 192, 223-237). 0 Either wrong or very uncertain determination 1 Possible but not certain pole determination. This will most often appear when a limited number of data sets is used, especially if methods other than lightcurve inversion are involved. 2 Good determination, based on large dataset. The solution consists of one or two solutions (and possibly their 180° mirrors). If two solutions, they may differ in both longitude and latitude but not by the simple 180° mirror. 3 Very good determination, based on large dataset, an ambiguity of about 180° in pole longitude might appear. 4 Excellent determination, pole position confirmed by methods based on independent datasets (for example, lightcurves and radar data, lightcurves and spacecraft fly-by). P A prograde rotation has been determined but no specific pole position has been determined. This will be followed by a 0 or 1, indicating the quality of the determination. R A retrograde rotation has been determined by no specific pole position has been determined. This will be followed by a 0 or 1, indicating the quality of the determination. If the Q value is blank, the given pole solution has not yet been reviewed under the new rating system. 4.9.2 SPECIAL ENTRIES ---------------------- Sometimes an entry will have a value of L1 = -1. This indicates no longitude was reported. The value of B1 has two interpretations If the latitude is -99.9, then no latitude was reported. This entry must have a Q value of P or R, meaning prograde or retrograde rotation was determined. This is usually by seeing how the synodic rotation period changed before, at, and after opposition. Other techniques than lightcurve inversion can also produce a sense of rotation but no longitude/latitude pair. If the latitude is |b| <= 90.0, then a latitude only solution was found, although it is usually more a "best guess" and can have substatial errors. Again, the Q rating must be P or R, which is assigned on the basis that positive latitudes imply prograde rotation and negative latitudes imply retrograde rotation. A negative longitude will not appear for Long2-Long4. 4.9.3 LC_SPINAXIS COLUMN MAPPING ------------------------------------- Field Format Pos Notes -------------------------------------------------------------------------------- Number I7 1-7 MPC-assigned number; empty if no number assigned Name A30 9-38 MPC-assigned name, or designation if not named SumPer F13.8 40-52 Rotation period from summary record, hours SumAmp F4.2 54-57 Maximum lightcurve amplitude from the summary record ShortRef A30 59-88 Short reference from lc_references table DateObs A10 90-99 Approximate mid-date (yyyy-mm-dd, 0h UT) of observations Long1 F5.1 101-105 Ecliptic longitude of the preferred pole Long1Err F5.1 107-111 Error in Long1 Lat1 F5.1 113-117 Ecliptic latitude of the preferred pole (always includes + or -) Lat1Err F5.1 119-123 Error in Lat1 Long2 F5.1 101-105 Ecliptic longitude of the first alternate pole Long2Err F5.1 107-111 Error in Long2 Lat2 F5.1 113-117 Ecliptic latitude of the first alternate pole (always includes + or -) Lat2Err F5.1 119-123 Error in Lat2 Long3 F5.1 101-105 Ecliptic longitude of the second alternate pole Long3Err F5.1 107-111 Error in Long3 Lat3 F5.1 113-117 Ecliptic latitude of the second alternate pole (always includes + or -) Lat3Err F5.1 119-123 Error in Lat3 Long4 F5.1 101-105 Ecliptic longitude of the third alternate pole Long4Err F5.1 107-111 Error in Long4 Lat4 F5.1 113-117 Ecliptic latitude of the third alternate pole (always includes + or -) Lat4Err F5.1 119-123 Error in Lat4 SidPer F13.8 125-137 Sidereal period of spin axis solution (for long/lat1) Model A1 139 Y/N; Y = Shape model reported. Q A4 141-144 Quality of pole solution (see section 4.8.1) 5.0.0 WIDE-FIELD SURVEYS AND SPARSE DATA SETS -------------------------------------------------------------------------------- 5.1.0 WIDE-FIELD SURVEYS ------------------------- Since about 2012, several papers have been published that made use of the Palomar Transit Factory survey. The combined papers have added more than 10,000 new asteroids to the LCDB. The first two papers, Polishook et al. (2012) and Chang et al. (2014), produced a manageable number of lightcurves, meaning that each one was reviewed by the LCDB authors and a U code assigned. More recent papers, e.g., Waszczak et al. (2015) and Chang et al. (2015), produced thousands of "reliable" lightcurves. For these two papers, and those likely to follow, it is not possible to review each lightcurve. As a result, the LCDB authors adopted the policy of assigning U = 2 to any lightcurve from the two later papers above where the original authors claimed to have found a reliable period. The Waszczak paper found a number of periods that were not considered reliable. These were assigned U = 1 in the LCDB. Where no period was reported, what information that was available, e.g., amplitude, was entered and no U code was assigned. Over time, at least some individual entries will be reviewed and, if necessary, the summary line will be updated. It should be noted that the Waszczak et al. (2015) paper reported observations on more than 50,000 asteroids but found less than 10,000 "reliable" periods, or about a 16% success rate. The Chang 2015 paper had about a 27% success rate. As a result, statistical studies should use the wide-field data with some caution since they have likely introduced substantial biases, e.g., against super-fast or super-slow rotators, tumblers, binary objects, and, probably most significantly, against objects with low amplitudes, i.e., A < ~0.10-0.12 mag. For a detailed look at these issues, the reader is referred to Warner, B.D., Harris, A.W. (2011) "Using sparse photometric data sets for asteroid lightcurve studies." Icarus 216, 610-624. Harris, A.W., Pravec, P., Warner, B.D. (2012) "Looking a gift horse in the mouth: Evaluation of wide-field asteroid photometric surveys." Icarus 221, 226-235. The LCDB authors anticipate having to handle the results based on similar large surveys in the future. These will be handled on a case-by-case basis. 5.2.0 SPARSE DATA SETS ----------------------- Sparse data sets differ from their wide-field counterparts in that they are generally the result of surveys such as the Catalina Sky Survey, i.e., 2-5 data points a night on a few nights each lunation over several years. A more extensive example is the Lowell Lightcurve Database (Bowell et al., 2014) that includes hundreds of observations for some asteroid over 10-15 years. These sparse data sets can be used exclusively in shape modeling and spin axis studies (e.g., Hanus et al., 2016). If a period and/or spin axis is generated by the use of sparse data _only_, the SPARSEDATA field will be set to TRUE in the details and/or summary record. Depending on the number of data points involved, the result may be given a U rating of 2 even though the NOTES flag will include 'N' for no published lightcurve. If the sole period result, the value is included on the summary line, which will also have the SPARSEDATA field set along with the U rating field. In those cases where sparse data are combined with dense lightcurves, the sparse data field will NOT be set but, as above, the result may be given a U rating and 'N' in the in NOTES field and, if the only period result, migrated to the summary line. 6.0.0 NUMBERS OF INTEREST ---------------------------------------------------------------------------- The numbers presented here are as of 2019 August 14. 6.0.1 OPRHAN RECORDS --------------------- No "orphan" records are in the lc_summary table. These are from publications that did not report any observations towards finding a lightcurve period and/or amplitude. Some examples are most of the IR survey papers (WISE, AKARI, SPITZER) that reported diameter and diameter. Others include those reporting only color indices or taxonomic classification. Likewise, if a summary record is orphaned, none of its detail lines are reported in the lc_details table. However, the subtables, e.g., lc_binary and lc_colorindex, DO include the details lines for orphaned summary records. In those tables, the number and name of the asteroid from the summary line are included in each record. 6.1.0 SUMMARY TABLE - OVERVIEW -------------------------------- Total Records: 325184 Non-Orphan: 24611 WideField: 17887 (orphan, detail source is from a WF survey) WideField: 15985 (non-orphan) SparseData: 0 (detail source is from a SD survey) SparseData: 0 (non-orphan) U >= 1-: 21294* (non-orphan) U >= 2-: 19564 (non-orphan) * This is the number of entries in the lc_summary table and so excludes summary lines where no period, amplitude, or U code was given. These "no data" lines are included to show that some lightcurve data are available but they were insufficient to make even an approximate guess of the period and/or amplitude. Pole: 2701 (could be just "retrograde vs. prograde" Tumblers: 504 Binaries: 504 (includes suspected) Binaries: 304 ('B' or 'M', i.e., considered confirmed) 6.1.0 SUMMARY TABLE: U >= 2- ONLY ------------------------------------ NEA: 1534 Binary: 95 (6.2%, includes 'B', 'M', and '?') Pole: 65 (4.2%) Hungaria: 463 Binary: 50 (10.8%, includes 'B', 'M', and '?') Pole: 34 (7.3%) Hilda: 159 Binary: 2 (1.3%, includes 'B', 'M', and '?') Pole: 21 (13.2%) Jupiter Trojans: 346 Binary: 4 (1.1%) Pole: 18 (5.2%) 6.1.1 SUMMARY TABLE: U >= 2- ONLY; MIN/MAX VALUES --------------------------------------------------- Shortest Period: 0.003298 h (11.87 s); 2017 QG18 Longest Period: 1880 h (78.33 days); (162058) 1997 AE12 Smallest Diameter: 0.003 km; 2006 RH120, 2010 WA, 2915 TC25 Largest Diameter: 2700 km; (136199) Eris Based on AmpMax value -------------------------- Largest Amplitude: 2.79 mag; 2014 KH39 Average Amp: 0.47 mag Total: 19655 Set All Amp 0.01-0.10: 526 ( 94 Wide/Sparse, 18% 2.7%) Amp 0.11-0.20: 2554 (1028 Wide/Sparse, 40% 5.2%) Amp 0.21-0.30: 2937 (1541 Wide/Sparse, 60% 7.8%) Amp 0.31-0.40: 2727 (1559 Wide/Sparse, 57% 13.9%) Amp 0.41-0.50: 2366 (1598 Wide/Sparse, 68% 12.0%) Amp 0.51-0.75: 4698 (3510 Wide/Sparse, 75% 23.9%) Amp 0.76-1.00: 2082 (1443 Wide/Sparse, 69% 10.6%) Amp 1.01-1.50: 562 ( 240 Wide/Sparse, 43% 2.9%) Amp > 1.50: 57 ( 5 Wide/Sparse, 9% 0.2%) 6.2.0 DETAILS TABLE - OVERVIEW ------------------------------- The numbers for the tumbler and binary subsets are going to be higher than reflected in the Summary table totals. This just indicates that not every suspected binary or tumbler was "good enough" to make it to the summary line. All numbers in each subset include multiple entries for a given asteroid. Total Records: 619159 (includes those w/o any LC data) With Period: 38919 (includes those w/o U rating) U >= 1-: 34982 (89.9% Wide/Sparse: 16911, 43.5%) U >= 2-: 32104 (82.5% Wide/Sparse: 15554, 40.0%) Pole: 3808/3495/3021 The first number is the records with a spin axis solution The second number is those with a period The third number is those with a period and U >= 2- Tumblers: 639/638/432 (307/174) The first number is the records that include 'T' in the notes field The second number is those with a period (precession and/or rotation) The third number is those with a period and U >= 2- Binaries: Total: 844 (includes 'B', 'M', and '?') Confirmed: 603 (includes 'B', 'M') 7.0 REFERENCES ----------------------------------------------------------------------- Bottke, W.F., Vokrouhlicky, D., Nesvorny, D. (2007). Nature 449, 48-53; personal communications. Bowell, E., Oszkiewicz, D.A., Wasserman, L.H., Muinonen, K., Penttila, A., Trilling, D.E. (2014). "Asteroid spin axis longitudes from the Lowell Observatory database." Meteoritics & Planetary Sci. 49, 95-102. Bus, S.J., Binzel, R.P. (2002a). "Phase II of the Small Main-Belt Asteroid Spectroscopic Survey. The Observations." Icarus 158, 106-145. Bus, S.J., Binzel, R.P. (2002b). "Phase II of the Small Main-Belt Asteroid Spectroscopic Survey. A Feature-Based Taxonomy." Icarus 158, 146-177. Chang, C.-K., Ip, W.-H., Lin, H.-W., Cheng, Y.-C., Ngeow, C.-C., Yang, T.-C., Waszczak, A., Kulkarni, S.R., Levitan, D., Sesar, B., Laher, R., Surace, J., Prince, T.A. (2014). "313 New Asteroid Rotation Periods from Palomar Transient Factory Observations." Ap. J. 788, A17. Chang, C.-K., Ip, W.-H., Lin, H.-W., Cheng, Y.-C., Ngeow, C.-C., Yang, T.-C., Waszczak, A., Kulkarni, S.R., Levitan, D., Sesar, B., Laher, R., Surace, J., Prince, T.A. (2015). “Asteroid Spin-rate Study Using the Intermediate Palomar Transient Factory.” Ap. J. Suppl. Ser. 219, A27. Durech, J., Sidorin, V., Kaasalainen, M. (2010). "DAMIT: a database of asteroid models." Astron. Astrophys. 513, A46. Hanus, J., Durech, J., Oszkiewicz, D.A., Behrend, R., Carry, B., Delbo, M., Adam, O., Afonina, V., Anquetin, R., Antonini, P., and 159 coauthors. (2016). "New and updated convex shape models of asteroids based on optical data from a large collaboration network." Astron. Astrophys. 586, A108. Harris, A.W., Young, J.W., Scaltriti, F., Zappala, V. (1984). "Lightcurves and phase relations of the asteroids 82 Alkmene and 444 Gyptis." Icarus 57, 251-258. Harris, A.W.; Harris, A.W. (1997). "On the Revision of Radiometric Albedos and Diameters of Asteroids." Icarus 126, 450-454. Harris, A.W., Pravec, P., Warner, B.D. (2012) "Looking a gift horse in the mouth: Evaluation of wide-field asteroid photometric surveys." Icarus 221, 226-235. Kryszczynska A., La Spina A., Paolicchi P., Harris A.W., Breiter S., Pravec P. (2007). "New findings on asteroid spin-vector distributions." Icarus 192, 223-237. Mainzer, A., Grav, T., Bauer, J., Masiero, J., McMillan, R.S., Cutri, R.M., Walker, R., Wright, E., Eisenhardt, P., Tholen, D.J., Spahr, T., Jedicke, R., Denneau, L., DeBaun, E., Elsbury, D., Gautier, T., Gomillion, S., Hand, E., Mo, W., Watikins, J., Wilkins, A., Bryngelson, G.L., Del Pino Molia, A., Desai, S., Gomez Camus, M., Hidalgo, S.L., Konstantopoulos, I., Larsen, J.A., Maleszewski, C., Malkan, M.A., Mauduit, J.-C., Mullan, B.L., Olszewski, E.W., Pforr, J., Saro, A., Scotti, J.V., Wasserman, L.H. (2011). "NEOWISE observations of near-Earth objects: Preliminary results." Ap. J. 743, A156. Polishook, D., Ofek, E. O., Waszczak, A., Kulkarni, S. R., Gal-Yam, A., Aharonson, O., Laher, R., Surace, J., Klein, C., Bloom, J., Brosch, N., Prialnik, D., Grillmair, C., Cenko, S. B., Kasliwal, M., Law, N., Levitan, D., Nugent, P., Poznanski, D., Quimby, R. (2012). "Asteroid rotation periods from the Palomar Transient Factory survey." Mon. Not. Royal Ast. Soc. 421, 2091-2108. Pravec, P., Harris, A.W., Scheirich, P., Kušnirák, P., Šarounová, L., Hergenrother, C.W., Mottola, S., Hicks, M.D., Masi, G., Krugly, Yu.N., Shevchenko, V.G., Nolan, M.C., Howell, E.S., Kaasalainen, M., Galád, A., Brown, P., Degraff, D.R., Lambert, J. V., Cooney, W.R., Foglia, S. (2005). "Tumbling asteroids." Icarus 173, 108-131. Pravec, P., Scheirich, P., Kusnirák, P., Sarounová, L., Mottola, S., Hahn, G., Brown, P., Esquerdo, G., Kaiser, N., Krzeminski, Z., and 47 coauthors (2006). "Photometric survey of binary near-Earth asteroids." Icarus 181, 63-93. Pravec, P., Vokrouhlicky, D., Polishook, D., Scheeres, D.J., Harris, A.W., Galad, A., Vaduvescu, O., Pozo, F., Barr, A., Longa, P., and 16 coauthors. (2010). "Formation of asteroid pairs by rotational fission," Nature 466, 1085-1088. Tedesco, E.F., Noah, P.V., Price, S.D. (2004). "IRAS Minor Planet Survey." IRAS-A-FPA-3-RDR-IMPS-V6.0. NASA Planetary Data System. Tholen, D.J. (1984). "Asteroid taxonomy from cluster analysis of Photometry." Doctoral Thesis. Univ. Arizona, Tucson. Usui, F., Kuroda, D., Müller, T.G., Hasegawa, S., Ishiguro, M., Ootsubo, T., Ishihara, D., Kataza, H., Takita, S., Oyabu, S., Ueno, M., Matsuhara, H., Onaka, T. (2011). "Asteroid Catalog Using Akari: AKARI/IRC Mid-Infrared Asteroid Survey." Pub. Ast. Soc. of Japan 63, 1117-1138. Veres, P., Jedicke, R., Fitzsimmons, A., Denneau, L., Granvik, M., Bolin, B., Chastel, S., Wainscoat, R.J., Burgett, W.S., Chambers, K.C., Flewelling, H., Kaiser, N., Magnier, E.A., Morgan, J.S., Price, P.A., Tonry, J.L., Waters, C. (2015). "Absolute magnitudes and slope parameters for 250,000 asteroids observed by Pan-STARRS PS1 - Preliminary results." Icarus 241, 34-47. Warner, B.D., Harris, A.W., Pravec, P. (2009). "The Asteroid Lightcurve Database." Icarus 202, 134-146. Updated 2018 Feb. http://www.minorplanet.info/lightcurvedatabase.html Warner, B.D., Harris, A.W. (2011) "Using sparse photometric data sets for asteroid lightcurve studies." Icarus 216, 610-624. Waszczak, A., Chang, C.-K., Ofek, E.O., Laher, R., Masci, F., Levitan, D., Surace, J., Cheng, Y.-C., Ip, W.-H., Kinoshita, D., Helou, G., Prince, T.A., Kulkarni, S. (2015). "Asteroid Light Curves from the Palomar Transient Factory Survey: Rotation Periods and Phase Functions from Sparse Photometry." Astron. J. 150, A75.