NOAO > Observing Info > Approved Programs > 2013A-0435
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NOAO > Observing Info > Approved Programs > 2013A-0435 |
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PI: Anne Verbiscer, University of Virginia, verbiscer@virginia.edu
Address: Department of Astronomy, PO Box 400325, Charlottesville, VA, 22904-4325, USA
CoI: Will Grundy, Lowell Observatory
CoI: Susan Benecchi, Carnegie Institution of Washington (Terrestrial Magn.)
CoI: David Rabinowitz, Yale University
Title: Mutual Event of Transneptunian Binary (79360) Sila-Nunam
Abstract:
The transneptunian binary (79360) Sila-Nunam (provisionally designated 1997
CS29) is currently undergoing mutual events in which the two nearly-equal
brightness components alternate in eclipsing and occulting each other as seen
from Earth (Grundy et al. 2012, Verbiscer et al. 2012a). The low eccentricity
of the orbit, determined from Hubble Space Telescope observations of the
resolved components (Grundy et al. 2012), and the coincidence of the system's
photometric lightcurve and orbital period are consistent with a system that
is tidally locked and synchronized, like that of Pluto-Charon. Mutual events
provide a rich opportunity to learn about size, shape, color, and albedo
patterns on the system components. Mutual events of Pluto-Charon observed
between 1985-1990 provided the first characterization of their albedo
distributions. The duration of the mutual event season depends on the size
and separation of the system components. Using sizes determined from thermal
observations, the mutual event season for Sila-Nunam should last about a
decade; however, the deepest, most central (and thus most informative) events
are predicted to be observable in the 2013 apparition, with progressively
shallower events observable thereafter for the next 4-5 years. Gemini-North
is ideally located to observe a complete mutual event of Sila-Nunam which
begins at 5:59 UT on 14 February 2013 and ends at 14:17. Since Sila-Nunam
will be near opposition, the target is visible to GMOS for the entire night.
This event is a rare opportunity to determine the size, density, and
albedo/color patterns on a primitive body which has likely been unaltered
since the time of Solar System formation.
National Optical Astronomy Observatory, 950 North Cherry Avenue, P.O. Box 26732, Tucson, Arizona 85726, Phone: (520) 318-8000, Fax: (520) 318-8360
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NOAO > Observing Info > Approved Programs > 2013A-0435 |
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