Constraints on the Surface Composition of Comet 28P/Neujmin 1

Campins, H.; Licandro, J.; Chamberlain, M.; Brown, R. H.
Bibliographical reference

American Astronomical Society, DPS Meeting #33, #31.08; Bulletin of the American Astronomical Society, Vol. 33, p.1094

Advertised on:
11
2001
Number of authors
4
IAC number of authors
0
Citations
2
Refereed citations
1
Description
Jupiter family comets, Centaurs and Transneptunian Objects (TNOs) are three populations of minor solar system objects that are believed to be closely related. Information about the surface composition of these objects is scarce yet essential to understanding the links between them. Comet 28P/Neujmin 1 is among the largest and least active of the Jupiter family comets (Campins et al. 1987, Astrophys. J. vol. 316, p. 847). We observed this comet with the NICS instrument on the 3.6-m Telescopio Nazionale Galileo (TNG). This instrumentation has already generated spectra diagnostic of the composition of TNOs (Licandro et al. 2001 Astron. and Astrophys. vol. 373, p. L29). We obtained a low resolution spectrum (R = 50) from 0.9 to 2.4 microns on June 1, 2001 UT. The comet's heliocentric and geocentric distances were 5.4 and 4.8 AU, respectively, and the phase angle was 9 degrees. A preliminary analysis indicates that the spectral structure observed is not consistent with that expected from water ice. Modeling of our spectrum is underway, but no specific mineral has been identified yet. The absence of a clear water ice signature in our spectrum is consistent with the results of Campins et al. (1987), who estimated that only 0.1% - 0.3% of this comet's surface is exposed water ice. This work was supported by NASA and NSF.