Cometary Activities of the Hyperbolic Asteroid A/2021 X2 Observed at Lulin Observatory
ATel #15597; Yu-Chi Cheng (NTNU-PHY, Taiwan) and Ya-Lin Wu (NTNU-PHY, Taiwan)
on 8 Sep 2022; 04:28 UT
Distributed as an Instant Email Notice Comets
Credential Certification: Yu-Chi Cheng (ycc312@g.ncu.edu.tw)
Subjects: Optical, Asteroid, Comet, Solar System Object, Transient
We report ongoing cometary activities of the hyperbolic asteroid A/2021 X2 (hereafter X2) from our optical imaging in August. A weak coma and a faint diffuse tail were observed on the 9th, 20th, 21st, and 24th of August when the heliocentric distance of X2 varied between 3.01 and 3.03 au. The FWHM of X2 is around 2.5" which is twice the mean seeing during the observation. Compared with the syndyne-synchrone dust curve, we suggest the dust ejecta was released more than 200 days ago. X2 appears highly variable due to time-varying coma obscuration. It is on a hyperbolic orbit (e>1) and has recently finished the perihelion passage (q = 2.99 au) in early July. These observations were performed with the Lulin 1-m telescope at Lulin Observatory (MPC code: D35), operated by the Institute of Astronomy, NCU, Taiwan.
Observing images, please note that the pixel scale of the images are ~ 0.69".
