New Constraint on the Atmosphere of (50000) Quaoar from a Stellar Occultation
Abstract
We report observations of a stellar occultation by the classical Kuiper Belt object (50000) Quaoar that occurred on 2019 June 28. A single-chord high-cadence (2 Hz) photometry data set was obtained with the Tomo-e Gozen CMOS camera mounted on the 1.05 m Schmidt telescope at Kiso Observatory. The obtained ingress and egress data do not show any indication of atmospheric refraction and allow new 1σ and 3σ upper limits of 6 and 16 nbar, respectively, to be set for the surface pressure of a pure methane atmosphere. These upper limits are lower than the saturation vapor pressure of methane at Quaoar’s expected mean surface temperature (T ∼ 44 K) and imply the absence of a ∼10 nbar-level global atmosphere formed by methane ice on Quaoar’s surface.
- Publication:
-
The Astronomical Journal
- Pub Date:
- December 2019
- DOI:
- 10.3847/1538-3881/ab5058
- arXiv:
- arXiv:1910.09988
- Bibcode:
- 2019AJ....158..236A
- Keywords:
-
- Kuiper Belt;
- Solar system astronomy;
- Solar system;
- Trans-Neptunian objects;
- Quaoar;
- Classical Kuiper Belt objects;
- 893;
- 1529;
- 1528;
- 1705;
- 1315;
- 250;
- Astrophysics - Earth and Planetary Astrophysics
- E-Print:
- 12 pages, 3 figures, accepted for publication in the Astronomical Journal