New Constraint on the Atmosphere of (50000) Quaoar from a Stellar Occultation
The Astronomical Journal, vol. 158, no. 6, pp. 236
Authors:
- Ko Arimatsu
- Ryou Ohsawa
- George L. Hashimoto
- Seitaro Urakawa
- Jun Takahashi
- Miyako Tozuka
- Yoichi Itoh
- Misato Yamashita
- Fumihiko Usui
- Tsutomu Aoki
- Noriaki Arima
- Mamoru Doi
- Makoto Ichiki
- Shiro Ikeda
- Yoshifusa Ita
- Toshihiro Kasuga
- Naoto Kobayashi
- Mitsuru Kokubo
- Masahiro Konishi
- Hiroyuki Maehara
- Noriyuki Matsunaga
- Takashi Miyata
- Mikio Morii
- Tomoki Morokuma
- Kentaro Motohara
- Yoshikazu Nakada
- Shin-ichiro Okumura
- Shigeyuki Sako
- Yuki Sarugaku
- Mikiya Sato
- Toshikazu Shigeyama
- Takao Soyano
- Hidenori Takahashi
- Ken’ichi Tarusawa
- Nozomu Tominaga
- Jun-ichi Watanabe
- Takuya Yamashita
- Makoto Yoshikawa
URL:
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 (2Hz) 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 1$\sigma$ and 3$\sigma$ 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$\sim$44 K) and imply the absence of a$\sim$10 nbar-level global atmosphere formed by methane ice on Quaoar’s surface.