Astronomy and Astrophysics – Astrophysics – Earth and Planetary Astrophysics
Scientific paper
2012-04-17
Astronomy and Astrophysics
Astrophysics
Earth and Planetary Astrophysics
In press in Icarus
Scientific paper
Hubble Space Telescope observations between 2001 and 2010 resolved the binary components of the Cold Classical transneptunian object (79360) Sila-Nunam (provisionally designated 1997 CS29). From these observations we have determined the circular, retrograde mutual orbit of Nunam relative to Sila with a period of 12.50995 \pm 0.00036 days and a semimajor axis of 2777 \pm 19 km. A multi-year season of mutual events, in which the two near-equal brightness bodies alternate in passing in front of one another as seen from Earth, is in progress right now, and on 2011 Feb. 1 UT, one such event was observed from two different telescopes. The mutual event season offers a rich opportunity to learn much more about this barely-resolvable binary system, potentially including component sizes, colors, shapes, and albedo patterns. The low eccentricity of the orbit and a photometric lightcurve that appears to coincide with the orbital period are consistent with a system that is tidally locked and synchronized, like the Pluto-Charon system. The orbital period and semimajor axis imply a system mass of (10.84 \pm 0.22) \times 10^18 kg, which can be combined with a size estimate based on Spitzer and Herschel thermal infrared observations to infer an average bulk density of 0.72 +0.37 -0.23 g cm^-3, comparable to the very low bulk densities estimated for small transneptunian binaries of other dynamical classes.
Benecchi Susan D.
Buie Marc William
Grundy Will M.
Levison Harold F.
Noll Keith S.
No associations
LandOfFree
Mutual Events in the Cold Classical Transneptunian Binary System Sila and Nunam does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Mutual Events in the Cold Classical Transneptunian Binary System Sila and Nunam, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Mutual Events in the Cold Classical Transneptunian Binary System Sila and Nunam will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-410757