Bibcode
Pinilla-Alonso, Noemi; Licandro, J.; Gil-Hutton, R.
Bibliographical reference
American Astronomical Society, DPS meeting #38, #40.03; Bulletin of the American Astronomical Society, Vol. 38, p.556
Advertised on:
9
2006
Citations
0
Refereed citations
0
Description
In this presentation we report visible and near infrared spectra
covering the 0.35-2.5 μm range of two big TNOs recently discovered,
2005 FY9 and 2003 EL61, and visible spectrum of
2003UB313 obtained with the 4.2 m William Herschel Telescope
and the 3.58 m Telescopio Nazionale Galileo sited at El Roque de Los
Muchachos Observatory (La Palma, Spain). In the case of 2005 FY9
and 2003UB313 the spectra of these large TNOs are
similar to that of Pluto, with an infrared region dominated by very
prominent absorption bands formed in solid CH4. The
icy-CH4 bands in these new giants are significantly stronger
than those of Pluto, implying that methane could be even more abundant
on its surface. At wavelengths sorter than 0.6 microns, the spectra are
almost featureless and red which most likely indicates the presence of
complex organics on the surface as being hypothesized for Pluto and many
other TNOs. The composition of the surface layers, in particular, the
presence of N2 ice is discussed based in the central
wavelength of methane-ice bands. In the case of 2003 El 61 we
compare our spectrum with Charon's one and find that they have very
similar characteristics, with a neutral featureless visible spectrum and
strong water ice features at 1.5 and 2.2 μm. The presence of such
deep water ice bands is not new among TNOs, it has been already refereed
in the spectrum 1996 TO66, 2002 TX300 , and the
brightest satellite of 2003 EL61. We complete our analysis of
the surface of 2003 EL61 with a comparative study of these
spectra.