1204.0899 (András Pál et al.)

"TNOs are Cool": A survey of the trans-Neptunian region -- VII. Size and surface characteristics of (90377) Sedna and 2010 EK139    [PDF]

András Pál, Csaba Kiss, Thomas G. Müller, Pablo Santos-Sanz, Esa Vilenius, Nikolett Szalai, Michael Mommert, Emmanuel Lellouch, Miriam Rengel, Paul Hartogh, Silvia Protopapa, John Stansberry, Jose-Luis Ortiz, René Duffard, Audrey Thirouin, Florence Henry, Audrey Delsanti

We present estimates of the basic physical properties (size and albedo) of (90377) Sedna, a prominent member of the detached trans-Neptunian object population and the recently discovered scattered disk object 2010 EK139, based on the recent observations acquired with the Herschel Space Observatory, within the "TNOs are Cool!" key programme. Our modeling of the thermal measurements shows that both objects have larger albedos and smaller sizes than the previous expectations, thus their surfaces might be covered by ices in a significantly larger fraction. The derived diameter of Sedna and 2010 EK139 are 995 +/- 80 km and 470 +35/-10 km, while the respective geometric albedos are pV 0.32 +/- 0.06 and 0.25 +0.02/-0.05. These estimates are based on thermophysical model techniques.

View original: http://arxiv.org/abs/1204.0899