Description of the IANNINI ASTEROID FAMILY SPECTRA bundle V1.0 ============================================================== Bundle Generation Date: 2020-02-28 Peer Review: 2009 Asteroid Review, 2009-06-03 Discipline node: Small Bodies Node Content description based on the data set catalog file description for the PDS3 version, EAR-A-I0039-4-IANNINISPEC-V1.0 ======================================================================================================================= Note: for PDS3 data sets migrated to PDS4, the following text is taken verbatim from the data set description and confidence level note of the PDS3 data set catalog file. In these cases, some details may not be correct as a description of the PDS4 bundle. Observations of 11 Iannini asteroid family members were obtained between November 2004 and March 2007 with the goal of obtaining a representative sample of Iannini family members over the visual wavelength region. Observations were made using the 10 m Keck II telescope, located on Mauna Kea, Hawaii. The ESI spectrograph (Sheinis et al. 2002) [SHENISETAL2002], equipped with a Lincoln Labs 2K x 4K CCD, was used in low dispersion mode with a prism to cover a wavelength range of approximately 0.39 to 1.0 microns. The resolution of ESI with a 6 arc second slit increases with wavelength from approximately 1150 at 0.39 microns to 2900 at 1.0 microns. Effects resulting from the asteroid's rotational lightcurve can be neglected when imaging the entire spectral range simultaneously. While the typical seeing at Keck gives images with a FWHM of less than or equal to 0.8 arcsec, a 1.0 arcsec wide slit was used through 2005, was increased to 1.25 arcsec for 2006, and finally increased to 6.0 arcsec for all subsequent nights. The slit width was increased because it allowed easier centering and alignment of the target onto the slit, and resulted in greater consistency amongst reduced spectra. The slit was aligned with the parallactic angle at the midpoint of each observation. Observations were conducted at the rate of motion of the targets and at airmass below 1.3. A total of 11 asteroids were successfully observed. The data have been published in Willman, et al. (2008Icar...195...663W) [WILLMANETAL2008]. The spectra show a familial similarity and are believed to be representative of young S class surfaces aged by space weathering over a few million years, the dynamically estimated collisional age of the family. During the data reduction process, spectra of solar analogs were divided into the raw asteroid spectra to produce values of relative reflectance. The standard procedure was to combine all analogs from the night into a master analog. This single hybrid analog was then used to calibrate each asteroid spectrum. The following is a list of the analogs that were used for each of the nights: 2004-11-10: BS448, BS582, BS660, BS720, BS2643, BS8041, BS9107 2006-01-04: BS4030, Hya64, SA98-978, SA102-1081 2006-01-05: BS4030, BS9107, Hya64, SA98-978 2007-03-10: SA98-978, SA102-1081, SA107-684 2006-10-01: SA110-361, SA113-276, SA93-101 Known issues or problems with the data ====================================== The user is referred to the paper in which these data were published: Willman, et al. (2008Icar...195...663W) [WILLMANETAL2008] for information about the confidence level of the data. The time intervals for each object in Table 1 of Willman, et al. (2008Icar...195...663W) [WILLMANETAL2008] correspond to the midpoints of the first and last observations. The START_TIME and STOP_TIME for the data presented here correspond to the start of the first exposure and the end of the last exposure respectively. The date of observation for asteroids (81550) 2000 HU23 and (150781) 2001 QO282 is incorrectly listed as 2007 March 09 in Table 1 of Willman, et al. (2008Icar...195...663W) [WILLMANETAL2008]. The correct date should read 2007 March 10. This correction has been made for the data presented here. PDS3 Source =========== Version 1.0 of this bundle was migrated from version 1.0 of the PDS3 data set EAR-A-I0039-4-IANNINISPEC-V1.0.