XRISM/Xtend Transient Search (XTS) detected X-ray flares likely from CD-61 901
ATel #18125; Y. Sakamoto (Tohoku U.), M. Shidatsu (Ehime U.), T. Hakamata, Y. Kanemaru, A. Miyamoto, Y. Omiya, T. Yoneyama (JAXA), M. Audard (U. de Geneve), E. Behar (Technion), K. Fukushima (TUS), K. Hasegawa (Kyoto U.), H. Iinuma (Tohoku U.), S. Inoue (Kyoto U.), Y. Ishihara (Chuo U.), N. Ishii (Kyoto U.), S. Ishiwata (Chuo U.), C. Kang (Ehime U.), R. Kawada (Kyoto U.), M. Kikuchi (Ehime U.), T. Kiyomoto (Saitama U.), T. Kohmura (TUS), H. Kuramoto (UOsaka), W. Lee (Kyoto U.), Y. Maeda (JAXA), H. Matsumoto (UOsaka), A. Miyamoto (UOsaka), M. Mizumoto (UTEF), Y. Motogami (Saitama U.), H. Murakami (TGU), T. Narita (RIKEN), M. Nobukawa (NUE), H. Noda (Tohoku U.), S. Ogawa (TUS), K. Sakamoto (Kyoto U.), H. Takahashi (Hiroshima U.), T. Takagi (Ehime U.), S. Takatsuka (UOsaka), F. Takisawa (Ehime U.), Y. Terada (Saitama U., JAXA), Y. Terashima (Ehime U.), Y. Tsuboi (Chuo U.), A. Uchida, H. Uchida (JAXA), T. Usuki (Ehime U.), A. Yoshimoto (NWU), M. Yoshimoto (Ehime U.), A. Heinrich (U. Chicago)
on 29 Oct 2026; 07:40 UT
Credential Certification: Megumi Shidatsu (shidatsu.megumi.wr@ehime-u.ac.jp)
Subjects: X-ray, Star, Transient
XRISM/Xtend Transient Search (XTS) detected X-ray flares from an X-ray source located at (R.A., Dec.) = (68.486, -61.493), with a systematic error of ∼ 40 arcsec. This position is consistent with that of CD-61 901, which is a rotating variable star at a distance of ∼93 pc. A flare of the same source was also detected by the XTS team on 2024-11-10 TT (ATel #17994).
The flares were detected on 2026-10-20 at ∼ 08:42 TT and on 2026-10-23 at ∼ 01:42 TT. In both cases, only the decaying phase was observed with Xtend, and the flare portions of the light curves were characterized by exponential functions. The maximum observed fluxes were 4.8 × 10-12 erg s-1 cm-2 and 3.2 × 10-12 erg s-1 cm-2 (0.4 – 10.0 keV), respectively, with e-folding times of ∼ 103 s in both cases.
