Bibcode
Ziffer, Julie; Campins, H.; Licandro, J.; Walker, M.; Deshpande, R.
Bibliographical reference
American Astronomical Society, DPS meeting #41, #34.01
Advertised on:
9
2009
Citations
0
Refereed citations
0
Description
We present rotationally resolved spectra of asteroid 490 Veritas in the
near-infrared (NIR) that show interesting differences.
Dynamical arguments indicate that 490 Veritas is the main fragment of a
recent (8.3 My) asteroidal break-up. We obtained NIR spectra
(0.8-2.4 microns) on UT May 11, 2008, using the SpeX instrument on
NASA's Infrared Telescope Facility (IRTF) on Mauna Kea, Hawaii.
Since published visible spectra of 490 Veritas show some variability, we
decided to observe its NIR spectrum at four distinct rotational phases.
Veritas's rotational light curve has a period of 7.93 hours with
amplitudes ranging from 0.3 to 0.5 magnitudes in the visible. We define
the time of our first observation as zero rotational phase and our
subsequent observations are at 0.29, 0.52, and 0.70. Our reflectance
spectra show a range of slopes. To characterize these slope differences,
we normalized each spectrum to 1.0 reflectance at 1.25 microns and
measured the reflectance at 2.2 microns. The values obtained are
reflectances of 0.99, 1.02, 0.98, and 0.93 at rotational phase 0.00,
0.29, 0.52, and 0.70, respectively. The uncertainty in each reflectance
value is ± 3%. In this work, we consider possible causes of this
variability, including heterogeneity of the parent body
and/or space weathering i.e., from different surfaces having
experienced various exposure ages.