학술논문
New constraint on the atmosphere of (50000) Quaoar from a stellar occultation
Document Type
Working Paper
Author
Arimatsu, Ko; Ohsawa, Ryou; Hashimoto, George L.; Urakawa, Seitaro; Takahashi, Jun; Tozuka, Miyako; Itoh, Yoichi; Yamashita, Misato; Usui, Fumihiko; Aoki, Tsutomu; Arima, Noriaki; Doi, Mamoru; Ichiki, Makoto; Ikeda, Shiro; Ita, Yoshifusa; Kasuga, Toshihiro; Kobayashi, Naoto; Kokubo, Mitsuru; Konishi, Masahiro; Maehara, Hiroyuki; Matsunaga, Noriyuki; Miyata, Takashi; Morii, Mikio; Morokuma, Tomoki; Motohara, Kentaro; Nakada, Yoshikazu; Okumura, Shin-ichiro; Sako, Shigeyuki; Sarugaku, Yuki; Sato, Mikiya; Shigeyama, Toshikazu; Soyano, Takao; Takahashi, Hidenori; Tarusawa, Ken'ichi; Tominaga, Nozomu; Watanabe, Jun-ichi; Yamashita, Takuya; Yoshikawa, Makoto
Source
Subject
Language
Abstract
We report observations of a stellar occultation by the classical Kuiper belt object (50000) Quaoar occurred on 28 June 2019. A single-chord high-cadence (2 Hz) photometry dataset 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 to set new $1\sigma$ and $3\sigma$ upper limits of 6 and 16 nbar, respectively, 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.
Comment: 12 pages, 3 figures, accepted for publication in the Astronomical Journal
Comment: 12 pages, 3 figures, accepted for publication in the Astronomical Journal