Bibcode
Hargrove, K.; Campins, H.; Kelley, M.; Fernandez, Y.; Ziffer, J.; Licandro, J.; Emery, J.; Cruikshank, D.; Hergenrother, C.; Pinilla-Alonso, N.; Clautice, D.
Referencia bibliográfica
American Geophysical Union, Spring Meeting 2008, abstract #P34A-06
Advertised on:
5
2008
Número de citas
0
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Descripción
Asteroid 944 Hidalgo is suspected of being an extinct comet.
Understanding the origin of this enigmatic object is relevant to several
areas of planetary astronomy, and the study of its surface composition
may be diagnostic of its origin. Silicates have been detected in active
comets, and on Jupiter Trojans. Our team investigated Hidalgo in the
8-30 micron range to determine the mineral composition and presence of
surface silicates. We chose this wavelength region because it is most
diagnostic for the detection of silicates. We applied to use NASA's
Spitzer Space Telescope as Hidalgo is too faint at these wavelengths for
ground- based telescopes. Once the data were collected, the continuum
was modeled and subtracted from the raw spectra. The result is a plot of
emissivity versus wavelength that shows clear emission features from
8-13 microns, and around 20 microns; both of which have been identified
with silicates. Our spectrum is compared with those of Jupiter Trojans,
which are believed to be related to comets, and comet Hale-Bopp. With
the project complete, we have demonstrated the presence of silicate
emissions in Hidalgo and strong similarity with spectra of Jupiter
Trojans and of active comets. These results argue in favor of Hidalgo
having formed further from the Sun than main belt asteroids. We conclude
that our findings are consistent, but not definitive, with Hidalgo being
of cometary origin. Understanding the composition of this body and
others like it is important for determining the origin of Earth's water.