Description of the Small Bodies Occultations bundle V3.0 ======================================================== Bundle Generation Date: 2020-10-07 Peer Review: 2019 Asteroid Review Discipline node: Small Bodies Node Content description for the Small Bodies Occultations bundle ============================================================ ======================================================== Content description for the Asteroid Occultations bundle ======================================================== This data set is intended to include all reported timings of observed asteroid, planet, and planetary satellite occultation events, as well as dimensions and other data derived from those timings. The dataset includes observations made over a period of more than 40 years, and has grown rapidly in recent years. Most of these timings are otherwise unpublished. This version is complete through to May 2019, with some observations through to Sept 2019. (The planet data are located along with the satellite data in the occsatlist and occsattime files.) In relatively recent years light curve inversion 3D models (Shape Models) have become available for a large number of asteroids via the DAMIT and ISAM web services. Wherever possible, the occultation observations are matched to available Shape Models. The dataset has been comprehensively reviewed in its entirety since the last version (PDS4 V2.0) to remove errors, ensure consistency of data over the duration of the observations, incorporate current observing techniques, include Shape Model identifications, and include volume-equivalent diameters derived from fits to Shape Models. ================ Acknowledgments ================ This dataset contains over 15,000 observations by more than 3,300 individuals from around the world, made over a period of more than 40 years. Observers have generally made these observations at their own expense, including occasions when they have traveled significant distances. Users of this database are requested to acknowledge their contributions with a statement like: We acknowledge the contributions of the over 3000 observers who have provided the observations in the dataset. Most of those observers are affiliated with one or more of: * European Asteroid Occultation Network (EAON) * International Occultation Timing Association (IOTA) * Japanese Occultation Information Network (JOIN) * RASNZ Occultations (The Occultation section of the Royal Astronomical Society of New Zealand) The occultation observations would not have been possible without the efforts of those who make, or have facilitated the making of (by way of software), predictions of occultation events over the duration of the observations in this dataset. Special mention must be made to the coordination software Occult Watcher which facilitates coordination of observers wherever they are located around the world. Final mention is made to the various software packages specifically designed to measure occultation events on video or CCD recordings. ============================= Occultations Analysis Program ============================= The observations are reduced using the software package Occult that is freely available for download at: http://www.lunar-occultations.com/iota/occult4.htm Processes for reporting observations have evolved over the duration of the dataset. For many years now observers submit an observation report that provides disappearance and reappearance timings (in UTC), observing location coordinates (WGS84) and elevation (Mean Sea Level), observing conditions and circumstances. The observations are reduced using the Besselian fundamental plane. The methodology is as follows. - The apparent position of the asteroid is computed at four 1-hour steps, with the time of the 2nd step nominally being the mean time of the observed occultation events (rounded to 0.1 hrs exactly). These positions are combined with the apparent positions of the star computed for the same times (corrected for stellar parallax, proper motion, and differential relativistic bending of the star and asteroid) to derive coordinates of the asteroid's shadow on the fundamental plane. Those coordinates are used to derive a cubic expression for the motion of the asteroid's shadow on the fundamental plane. - For each reported time, the (x,y) coordinate of the observer on the fundamental plane is computed. - The reported time of the first Disappearance or Reappearance event is used as a reference time. All observer positions on the fundamental plane are transposed to their position as at the reference time, using the motion of the asteroid's shadow. This creates a set of (x,y) observer coordinates on a reference frame that is fixed relative to the moving asteroid's shadow. - For fitting purposes, the origin of the (x,y) coordinates on the moving reference frame is set at the mean location of the (x,y) observer coordinates. Most commonly, the events used to define the origin of the reference frame are all Disappearance and Reappearance observations. However: * Events given a zero weight, and Miss events, are excluded; * If the star is a double star, only events involving the primary component are used to define the origin of the reference frame. * If a satellite is involved, the relative motion may be unknown. To this end, the reference frame (including the reference time) is defined using only events involving the satellite. This results in the position of the main body being transposed in that reference frame in accordance with its (presumably) dominant motion, to the mean time of the satellite events - thereby ensuring correct evaluation of the separation and position angle at the reference time. For a small number of satellites an ephemeris is available from the IMCCE Miriade system, and the 'known' relative motion of the satellite is incorporated. - Fitting a shape model, ellipse, double star solution, and satellite solution, occurs on this reference frame. - The astrometric position of the asteroid is derived from the location of the center of the fitted shape model or ellipse as transposed to the fundamental plane. The event time is the reference time. The location is converted to the asteroid's apparent geocentric offset in Right Ascension and Declination from the star using the asteroid's apparent geocentric parallax as at the event time. This is converted to an offset in the J2000 reference frame using standard expressions, and corrected for differential aberration. - If the event involves a double star, there may be a single solution, two solutions, or four solutions (depending upon the number of observed chords). The solution provides a Separation and Position Angle on the Apparent reference frame. For reporting purposes the Position Angle is converted to the BCRS reference frame. - For Miss events, the listed time is generally set to be the time when the miss chord passes closest to the ellipse fitted to the event. ============ Deriving data from the observations ============ For each event in the dataset a quality code is provided. That code has the following definitions: 0 = 'No reliable position or size'. Such events have been assessed as being unreliable. 1 = 'Astrometry only. No reliable size'. Such events typically involve only a small number of observed chords. The event can be used to report astrometry, but nothing meaningful about the asteroid's size. 2 = 'Limits on size, but no shape'. The chords provide a poor coverage around the profile, but a diameter of the asteroid is determinable (often with a fit to a shape model) 3 = 'Reliable size. Can fit to shape models'. There is good coverage around much of the profile enabling a reliable determination of the asteroid's size - even without a shape model 4 = 'Resolution better than shape models'. The profile of the asteroid well covered with highly consistent results. ============================== Star identifiers and positions; gravitational deflection ============================== The star identifiers used in this dataset are HIP (for Hipparcos2), Tycho2, UCAC4, USNO-B1, and NOMAD (in order of priority). These identifiers are merely for identification purposes; for 99.8% of the events the source of the star position is Gaia DR2. The listed BCRS position of the star for the date of the event (used as the reference point for reporting astrometry) incorporates stellar parallax, proper motion and foreshortening. The star position is not corrected for gravitational light deflection. The gravitational light deflection for the asteroid is always less than that for the star occulted. The dataset provides the 'observed' distance of the asteroid from the star (that is, a distance that includes the differing deflections of the star and asteroid), and the correction to be added to that distance to give the distance from the BCRS star position that is free of gravitational deflection. There are only 10 events where the star position has not come from Gaia DR2. They are: Eight events involving four stars too bright for Gaia DR2, where the positions have been taken from Hipparcos2: * HIP 31681 = gamma Gem: 1991 Jan 13 [Myrrha] * HIP 49669 = Regulus: 1959 July 7 [Venus], 2005 Oct 19 [Rhodope], 2015 May 24 [Dagmar] and 2016 Oct 13 [Adorea] * HIP 72217: 1970 Sep 25 [Venus] * HIP 84012 = eta Oph: 2004 Sep 6 [Nephthys], 2018 Feb 18 [Aeria] Two events (with Tycho2 identifiers) where the positions have been taken from the UCAC4 catalog: * Tycho2 1299-00981-1: 2012 Oct 5 [Thia] * Tycho2 1318-00830-1: 2009 Dec 15 [Russia] ============ Shape Models ============ The dataset includes Shape model fits wherever possible. Two sources of Shape Models have been used: * DAMIT [Database of Asteroid Models from Inversion Techniques] https://astro.troja.mff.cuni.cz/projects/asteroids3D/. [See also Durech et al. (2010), DAMIT: a database of asteroid models https://ui.adsabs.harvard.edu/abs/2010A%26A...513A..46D/abstract] * ISAM [Interactive Service for Asteroid Models] http://isam.astro.amu.edu.pl/ These sources have a very high degree of overlap in available models. However there are significant differences in the nature of support information that is available. A shape model quality setting is provided, with the following definitions: 0 = Not fitted. Too few chords to make a fit to the shape model. 1 = Bad occn data. The occultation observations are either inconsistent or unreliable, with no ready way of distinguishing between reliable and unreliable observations 2 = Model wrong. The shape model is clearly inconsistent with the observed chords 3 = Minimum Dia. Usually associated with a single chord observation, with that chord being matched to the largest dimension of the shape model to give its minimum diameter 4 = Diameter but no fit. The chords do not sensibly match the shape model, yet it is possible to derive minimum and maximum possible diameters. [NOTE: flag 1 - Model wrong - should be used unless there is a degree of confidence that the derived diameters are 'in the right ball-park'] 5 = Poor fit. The shape model is generally consistent with the observed chords - but has some broad deviations 6 = Good fit.The shape model has a high degree of correspondence with the observed chords. The Shape model fit does not involve a redetermination of the shape of the shape model. It is simply a matching of the shape model (with possible rotational variation) to obtain the best fit of the chords to the shape model. The diameter of the asteroid is obtained by deriving the length of the the absolute scale of the shape model on the projection of the occultation chords. ============== Data ============== The asteroid occultation timing data are contained in two files. The occlist file lists one occultation per line, along with the identification of the asteroid and star, and additional information about the star including RA and Dec. These files also include the major and minor axes derived from the timings for that occultation, the fit with up to 10 shape models, and information about the analysis. The list is chronological, with an occultation ID assigned to each event. The occtimings file lists the individual timings for each occultation event (with one disappearance and reappearance per line) as well as information about the observing site location and observational circumstances. Two analogous files, occsatlist and occsattime, contain data for occultations by planets and planetary satellites. Kepler2 star cross-reference: The Kepler2 mission is looking at fields around the ecliptic. An asteroidal occultation light curve provides a relatively high resolution light curve of the star - better than can be obtained by most (if not all) other ground-based techniques (including speckle) - thereby providing information that may be of use in the analysis of K2 data. A link/flag between stars observed in an asteroidal occultation with stars that have been selected as target stars in the Kepler2 mission is included in the files occlist and occsatlist. With the cessation of the Kepler2 mission in October 2018, the identification of Kepler2 stars is complete for observations contained in this dataset. Events in the future will be linked to Kepler2 stars when appropriate. ============== Ancillary Data ============== Summary files, occsummary.tab and occsatsummary.tab, contain the major and minor axes and position angles from the elliptical or circular fits. occsummary.tab also contains up to 8 volume-equivalent diameters derived from fits to shape models. The occsummary.tab provides convenient access to all determined asteroid diameters. Asteroids, and planets/satellites, are included in these files if the fit quality is 2 or greater. Additionally, asteroids are included in occsummary.tab if at least one of the shape model fits has a shape model quality setting of 3 or greater; even though the chord(s) are insufficient to determine a diameter of the asteroid, the chord(s) may be sufficient to set a minimum size of the asteroid. An image file occultations.pdf is located in the document directory. It contains images of the 'best' occultation observations. That is, events with fit quality code 3 or 4. There are 385 images, which is almost 9% of all events. The scale of the images varies according to the object. If a satellite is involved, the scale is reduced so as to show both the primary object and the satellite. ===================== Modification History ==================== The first version of this data set, introduced in 2003, included occultations only through to 1998. The update of 2004 not only added occultations through to March 1, 2004, but also provided a more systematic arrangement of the data. The data set has been updated annually since then. From late 2018 to mid-2019 the dataset was reviewed and modernized to cater for more recent observational techniques, and to incorporate the results of shape model fitting. The number of asteroid occultations included in each successive version is as follows: Year: Version: Number of occultations: 2003 V1.0 183 2004 V2.0 524 2005 V3.0 680 2006 V4.0 865 2007 V5.0 1055 2008 V6.0 1203 2009 V7.0 1417 2010 V8.0 1662 2011 V9.0 1935 2012 V10.0 2102 2013 V11.0 2275 2014 V12.0 2469 2015 V13.0 2717 2016 V14.0 2933 2017 PDS4 V1.0 3224 2018 PDS4 V2.0 3598 2019 PDS4 V3.0 4455 Caveats to the data user ======================== ============ Data set revision ============ The dataset underlying this archive has been revised from previous versions to identify and correct errors, review the reliability of observations, incorporate modern observing techniques, and to include information about fits to asteroid shape models. The revision involved the individual review of each of the more than 4300 events. The revision updated a number of data fields, and added an extra data item. Two fields have transitional issues: * Signal-to-Noise. This is a new data element, with no data being available for most events before 2019 and a continuing non-availability for many new observations. The value of SNR is 0 [zero] whenever data is not available. * Method of observation. Prior to the revision there were several categories relating to visual observations - reflective of typical observation techniques prior to 2000. Those have been replaced by a single 'Visual' category. In the revision the majority of old visual flags did not get translated into the new Visual category; it may validly be assumed that any observation where the observing method is 'Unspecified' was made visually; this is especially the case if there is a value for Personal Equation. ============ Site coordinates ============ The majority of observations have been made in Europe, Japan, North America, Australia and New Zealand. The dataset includes a field for the geodetic datum. The field includes tags for WGS84, ED1950, NAD1927, Tokyo and GB1936 - but not AGD1966 nor NZ1949. The transition from national coordinates to WGS84 coordinates occurred over quite a few years. For many events - but especially the older events - this field is not set. The approximate maximum offsets between various national geodetic datums and WGS84 are: * Europe (ED1950) 150m * Japan (Tokyo) 500m * North America (NAD1927) 150m * Great Britain (GB1936) 200m * Australia (AGD1966) 200m * New Zealand (NZ1949) 200m The effect of these offsets is two-fold: a. when fitting chords derived using different datums, relative chord displacements up to the datum offset might occur. However (apart from very rare trans-continental observations) this can only occur during a transitional period when coordinates from a region were being reported against differing datums. Additionally, in practice (especially having regard to observational uncertainties at those times) any such 'error' in the chord placements is generally too small to be noticeable. b. the derived astrometric position of the asteroid is potentially affected. For all but the Tokyo datum, reductions based on the WGS84 datum are fully adequate at the 0.1mas level; for the Tokyo datum 'errors' of up to about 0.3mas might arise. For this reason special effort has been made to ensure all site coordinates based on the Tokyo datum have that datum set in the dataset (all instances are before 2003). The dataset includes an event observed from the Kuiper Airborne Observatory [KAO](1978 May 29), an event observed from an F18 fighter jet (2000 Oct 10), and an event observed from the Stratospheric Observatory for Infrared Astronomy [SOFIA] (2015 June 29). For these separate entries exist for the D and R events, as the site coordinates differ as a result of the aircraft movement. The datum of the site coordinates for these observations is unknown (presumably NAD1927). The position of the KAO was uncertain by about 1km [THE DIAMETER OF PALLAS FROM ITS OCCULTATION OF SAO 85009 (1979) AJ 84 at pg.262]. For the SOFIA observation, the times and aircraft location were deduced from a conference presentation. An issue that has caused problems in the past is ensuring the sign of Longitude is correct. Current processing regimes are good at ensuring the sign is correct. The greatest risk of having the wrong sign occurs when the longitude is within about 10 degrees of the Greenwich meridian. While every effort has been made to validate past observations, it remains possible that a very small number of observations before about 2005 might have an undetected incorrect sign for an observer's longitude. ============ Observer names and locations ============ The data set allows for the names of up to two observers, and a flag if there were more than two observers. There is a lack of overall consistency in observer names. The majority of names include a first name (or initial) together with a family name, whereas many old observations contain just the family name. Additionally there are typographical errors of various kinds. Efforts have been made to identify and correct name errors, but undoubtedly some errors remain. Additionally there are issues of whether a person has reported using their 'true' first name or a 'familiar' version [for example, Robert vs Bob, William vs Bill], as well as some cultural differences in how family names are constructed; no effort has been made to try and regularize such issues. For a number of events the name of the actual observer is not known - just the name of the observatory or observing group. The field for the Observer location is frequently empty, as a result of variable data collection regimes over time and across the observing regions. Its prime purpose is to provide a low-level means of confirming the validity of the specified site coordinates. Similarly for the field giving a two- or three-letter country code (or potentially state codes for Australia, Canada, and the USA). ============ Shape Model fits ============ Where a diameter is derived by fitting to a shape model, we have provided a 'volume-equivalent diameter'. That is, the diameter of a sphere having the same volume as the shape model. Also listed is the Surface-Diameter/Volume-Diameter ratio - the ratio of the Surface-equivalent diameter to the Volume-equivalent diameter of the shape model. The Surface Equivalent diameter is apparently always greater than the volume-equivalent diameter. The fit to shape models is readily available in the occsummary list. All fits have been made by way of a visual comparison of the occultation chords to the shape model. Shape models have been associated with all relevant events, irrespective of whether the occultation data was sufficient to derive a fit to the shape model. One category of shape model fit is 'Minimum diameter'. This typically involves an occultation with only one (or a small number of closely-spaced) chords - such that the correct location of the chord on the shape model is indeterminate. We have fitted the chord to the maximum extension of the asteroid to derive a minimum diameter of the asteroid consistent with that chord - provided the chord length is greater than about 80% of the expected diameter; otherwise the shape model is flagged as 'Unfitted'. The fit for each event has been made solely on the basis of that event. A definitive fit of an asteroid to shape models requires fitting all events of a particular asteroid to a shape model, at the same time allowing for a change in the asteroid's rotational period. This is a task for the future - it has not been undertaken with this dataset. Differences between observed chords and a shape model can be caused by any of: * inaccuracies in the occultation data * inadequacies in the shape model * the shape model being incorrect. This issue has two aspects: 1. When a shape model is determined there are generally two different solutions for the axis of rotation, with corresponding different shapes. Occultation observations potentially/frequently identify the 'correct' model; 2. It may be that all available shape models are incorrect. Where the observation was sufficient to center the shape model on the observed chords, the uncertainty in the astrometric position is set to 0.02 of the asteroid's diameter - to reflect the accuracy provided by the shape model, the uncertainty in the detail of the shape model, and the uncertainty in fitting the shape model to the observed chords. Ultimately occultations and shape models have an iterative relationship, with occultation chords providing a basis for improving shape models, and the subsequent fit of the occultation chords to improved shape models providing an improved diameter determination. ============ Asteroid satellites ============ The dataset includes a number of observations involving satellites of asteroids. In the reduction process the primary solution for such events is the Separation and Position Angle of the satellite from the primary body. However in one instance (2010 June 14) the observed occultation was of the satellite only - (617) 1 Menoetius. In such cases the dataset includes a nominal entry (based on prediction) for the main body of the asteroid, with the Separation and Position Angle of the satellite being referenced to that nominal entry. Importantly, any derivation of the astrometric position of the satellite with regard to the star needs to be a combination of the offset of the nominal main body from the star plus the offset of the satellite from the nominal main body. ============ Accuracy/Reliability ============ Early occultation observations were hampered by low prediction accuracies associated with the accuracy limitations inherent in star catalogues and asteroid ephemerides prior to the Hipparcos mission, compounded by the consequential effect of visual observers needing to monitor the relevant star for perhaps 10's of minutes (with associated problems of reliability). These issues have improved over time with: * Hipparcos {including Tycho2) - providing accurate positions for brighter stars, free of zonal errors * UCAC catalogues (2, 3 and 4) - providing accurate star positions on the Hipparcos reference frame, for stars down to magnitude 16 * Astrometry of asteroids being reduced against the Hipparcos reference frame (typically via UCAC), removing zonal error problems from asteroid astrometry * the move from visual to video observing techniques, which commenced in the late 1990's. * improving time reliability by way of video time insertion based on GPS time signals, which commenced in the early 2000's * Gaia astrometry, which essentially reduced prediction uncertainty to uncertainty in the asteroid's ephemeris This history is apparent in the dataset by way of the increase in the number of successfully observed events each year. To validate observations, the dataset generally includes a 'prediction' line with each event. This prediction line is not a basis for computation of O-C values; indeed, the location of the prediction line depends on the ephemeris used to generate that prediction - and this is variable throughout the dataset. Rather its purpose is merely to identify erroneous observations, through the level of (in)consistency with that prediction. In reviewing events prior 2008, prediction lines were generated using asteroid elements generated using the JPL Horizons system; comments in the records may refer to such prediction lines as a 'postdiction'. In later years prediction lines are generally derived from the actual prediction for that event. The confidence level in the results of each event is indicated by way of the 'Quality Code for fit'. The lowest level is: ' 0 = 'No reliable position or size' The quality of the observations is insufficient to allow a reliable fit to either the asteroid's diameter or position ' The dataset contains 241 events (6% of the dataset) having this Quality code. Reasons include: * the observation is 'wrong' in the sense that it is greatly inconsistent with the prediction line. [Probable causes include long observing periods for visual observers, poor observing conditions, the difficulties with distinguishing between short events and atmospheric effects, and difficulties in detecting small magnitude changes (especially for visual observations).] * inconsistent observations for an event * single-chord events, where the observer only obtained a (reliable) time for one or other the D and R events. In the years prior to 2001 'false' observations ran between 10% and 50% of events, with the major causative factor being the combination of low prediction accuracy and visual observing for a long duration. Since 2008 the rate has been less than 4%, with the major causative factor being a partial observation (eg one event obscured by cloud) rather than an erroneous observation. Data for these events should usually be disregarded. Nevertheless these events are retained in the dataset. The following are those 241 events. 1958 2 19 (3) Juno 1970 9 25 (P2M00) Venus 1978 10 25 (12) Victoria 1979 4 6 (39) Laetitia 1982 12 13 (14) Irene 1983 3 11 (19) Fortuna 1983 8 8 (10) Hygiea 1984 1 30 (194) Prokne 1984 8 8 (87) Sylvia 1985 2 27 (53) Kalypso 1985 3 28 (42) Isis 1985 4 21 (12) Victoria 1985 5 1 (746) Marlu 1985 8 22 (1036) Ganymed 1985 9 1 (230) Athamantis 1986 1 15 (510) Mabella 1986 5 12 (336) Lacadiera 1986 10 4 (38) Leda 1986 12 2 (125) Liberatrix 1987 2 18 (320) Katharina 1988 3 8 (10) Hygiea 1988 8 13 (1206) Numerowia 1989 1 24 (275) Sapientia 1989 4 9 (313) Chaldaea 1989 4 23 (342) Endymion 1989 8 19 (4) Vesta 1989 12 2 (895) Helio 1990 3 11 (444) Gyptis 1990 9 24 (19) Fortuna 1990 12 9 (704) Interamnia 1991 4 2 (217) Eudora 1991 6 13 (423) Diotima 1991 6 15 (356) Liguria 1991 12 31 (50) Virginia 1992 1 8 (13) Egeria 1992 3 20 (48) Doris 1993 12 17 (30) Urania 1994 1 26 (45) Eugenia 1994 2 16 (712) Boliviana 1994 3 11 (152) Atala 1994 3 14 (56) Melete 1994 8 22 (1) Ceres 1995 2 13 (654) Zelinda 1995 4 5 (105) Artemis 1996 11 9 (892) Seeligeria 1997 1 6 (363) Padua 1997 1 22 (50) Virginia 1997 2 18 (445) Edna 1997 2 26 (386) Siegena 1997 6 30 (87) Sylvia 1997 11 3 (524) Fidelio 1998 1 20 (914) Palisana 1998 1 23 (39) Laetitia 1998 2 4 (569) Misa 1998 2 14 (449) Hamburga 1998 2 15 (417) Suevia 1998 2 27 (220) Stephania 1998 4 19 (924) Toni 1998 5 23 (353) Ruperto-Carola 1998 6 24 (242) Kriemhild 1998 9 29 (47) Aglaja 1998 10 2 (250) Bettina 1999 1 6 (250) Bettina 1999 1 6 (510) Mabella 1999 2 6 (674) Rachele 1999 2 18 (77) Frigga 1999 5 16 (492) Gismonda 1999 5 19 (17) Thetis 1999 8 17 (346) Hermentaria 1999 9 6 (194) Prokne 2000 2 29 (1357) Khama 2000 3 10 (314) Rosalia 2000 5 1 (146) Lucina 2000 5 28 (14) Irene 2000 6 17 (164) Eva 2000 10 4 (135) Hertha 2000 12 2 (300) Geraldina 2001 4 25 (2920) Automedon 2001 7 20 (1242) Zambesia 2001 7 27 (45) Eugenia 2001 9 28 (654) Zelinda 2001 11 21 (14) Irene 2001 12 9 (914) Palisana 2002 1 17 (1031) Arctica 2002 2 24 (364) Isara 2002 4 9 (36) Atalante 2002 4 15 (79) Eurynome 2002 8 25 (119) Althaea 2002 11 13 (1049) Gotho 2002 11 18 (1049) Gotho 2002 12 2 (1300) Marcelle 2003 1 16 (371) Bohemia 2003 4 9 (693) Zerbinetta 2003 6 3 (287) Nephthys 2003 6 8 (390) Alma 2003 7 9 (1432) Ethiopia 2003 7 25 (2105) Gudy 2003 8 3 (96) Aegle 2003 9 11 (357) Ninina 2003 10 20 (99) Dike 2004 3 17 (1765) Wrubel 2004 3 19 (250) Bettina 2004 4 18 (667) Denise 2004 4 22 (2060) Chiron 2004 5 3 (275) Sapientia 2004 5 16 (98) Ianthe 2004 7 9 (55) Pandora 2004 8 8 (344) Desiderata 2004 8 10 (1685) Toro 2004 8 23 (1491) Balduinus 2004 8 24 (1243) Pamela 2004 9 29 (223) Rosa 2004 10 6 (856) Backlunda 2004 11 2 (1191) Alfaterna 2004 11 28 (80) Sappho 2004 12 10 (238) Hypatia 2004 12 24 (779) Nina 2005 1 16 (41948) 2000 XX7 2005 4 17 (3714) Kenrussell 2005 5 28 (1977) Shura 2005 7 12 (1015) Christa 2005 7 17 (8126) Chanwainam 2005 8 17 (24) Themis 2005 9 3 (222) Lucia 2005 9 6 (680) Genoveva 2005 9 8 (814) Tauris 2005 9 30 (243) Ida 2005 10 20 (1235) Schorria 2005 12 11 (628) Christine 2005 12 11 (524) Fidelio 2005 12 18 (3311) Podobed 2006 1 5 (748) Simeisa 2006 2 28 (328) Gudrun 2006 5 14 (1736) Floirac 2006 5 26 (1143) Odysseus 2006 7 2 (1330) Spiridonia 2006 7 10 (1847) Stobbe 2006 8 6 (2291) Kevo 2006 8 16 (601) Nerthus 2006 11 21 (302) Clarissa 2006 11 26 (422) Berolina 2006 12 3 (326) Tamara 2006 12 10 (4790) Petrpravec 2007 1 14 (916) America 2007 1 18 (1502) Arenda 2007 1 21 (72) Feronia 2007 2 5 (921) Jovita 2007 3 24 (22068) 2000 AG103 2007 4 26 (519) Sylvania 2007 5 17 (225) Henrietta 2007 5 27 (640) Brambilla 2007 6 19 (334) Chicago 2007 8 13 (2352) Kurchatov 2007 10 7 (1881) Shao 2007 10 19 (1214) Richilde 2007 10 22 (239) Adrastea 2007 10 26 (203) Pompeja 2007 10 29 (663) Gerlinde 2007 10 30 (4614) Masamura 2007 11 23 (47877) 2000 FE23 2008 2 11 (285536) 2000 GP73 2008 3 7 (7) Iris 2008 4 17 (5508) Gomyou 2008 7 4 (449) Hamburga 2008 11 9 (209) Dido 2008 11 20 (129) Antigone 2008 12 20 (312) Pierretta 2009 3 20 (1329) Eliane 2009 6 5 (P9M03) Hydra 2009 7 19 (221) Eos 2009 9 15 (42) Isis 2009 9 25 (63195) 2000 YN120 2010 8 5 (662) Newtonia 2010 8 21 (1746) Brouwer 2010 8 27 (24) Themis 2010 10 3 (1570) Brunonia 2010 10 10 (347) Pariana 2010 12 28 (375) Ursula 2010 12 31 (565) Marbachia 2011 1 14 (619) Triberga 2011 3 10 (P9M00) Pluto 2011 4 17 (1583) Antilochus 2011 12 28 (407) Arachne 2012 1 4 (203) Pompeja 2012 3 13 (426) Hippo 2012 4 28 (179) Klytaemnestra 2012 6 25 (60558) Echeclus 2012 8 16 (2415) Ganesa 2012 9 5 (6959) Mikkelkocha 2012 9 22 (267) Tirza 2013 3 14 (269) Justitia 2013 3 17 (25) Phocaea 2013 3 26 (2106) Hugo 2013 5 7 (107) Camilla 2013 6 6 (6) Hebe 2013 7 28 (237) Coelestina 2014 1 6 (87) Sylvia 2014 4 16 (P2M00) Venus 2014 9 3 (16) Psyche 2014 9 7 (806) Gyldenia 2014 12 22 (52003) 2001 VB77 2015 2 3 (959) Arne 2015 4 30 (306) Unitas 2015 6 26 (448) Natalie 2015 7 31 (36) Atalante 2015 8 27 (657) Gunlod 2015 8 27 (351) Yrsa 2015 12 7 (334) Chicago 2016 1 24 (250) Bettina 2016 4 5 (47644) 2000 CO36 2016 5 20 (50) Virginia 2016 6 12 (10199) Chariklo 2016 7 9 (P6M06) Titan 2016 7 14 (P9M00) Pluto 2016 7 24 (1125) China 2016 8 1 (51) Nemausa 2017 4 9 (79) Eurynome 2017 11 14 (1211) Bressole 2017 12 19 (20) Massalia 2018 2 13 (1940) Whipple 2018 4 17 (852) Wladilena 2018 6 19 (940) Kordula 2018 6 20 (676) Melitta 2018 7 16 (2277) Moreau 2018 9 4 (52) Europa 2018 9 20 (6) Hebe 2018 9 23 (2875) Lagerkvist 2018 10 23 (1467) Mashona 2018 11 9 (63104) 2000 WR151 2018 11 14 (1258) Sicilia 2018 11 16 (839) Valborg 2019 1 22 (2) Pallas 2019 2 16 (10812) Grotlingbo 2019 2 16 (22) Kalliope 2019 2 25 (120143) 2003 GG42 2019 2 27 (1796) Riga 2019 3 3 (6) Hebe 2019 3 7 (433) Eros 2019 3 17 (201) Penelope 2019 4 15 (4716) Urey 2019 5 2 (551) Ortrud