LEIA detects a bright X-ray flare likely associated with the nearby eruptive variable star AO Men
ATel #16352; H. N. Yang (NAOC, CAS), W. J. Zhang (NAOC, CAS), C. C. Jin (NAOC, CAS), Y. Liu (NAOC, CAS), Z. X. Ling (NAOC, CAS), C. Zhang (NAOC, CAS), W. Chen (NAOC, CAS), H. Q. Cheng (NAOC, CAS), C. Z. Cui (NAOC, CAS), D. W. Fan (NAOC, CAS), H. B. Hu (NAOC, CAS), J. W. Hu (NAOC, CAS), M. H. Huang (NAOC, CAS), D. M. Li (BNU), D. Y. Li (NAOC, CAS), Q. X. Li (BNU), T. Y. Lian (NAOC, CAS), H. Y. Liu (NAOC, CAS), M. J. Liu (NAOC, CAS), Z. Z. Lv (NAOC, CAS), X. Mao (NAOC, CAS), H. W. Pan (NAOC, CAS), X. Pan (NAOC, CAS), H. Sun (NAOC, CAS), C. Y. Wang (THU), W. X. Wang (NAOC, CAS), Y. L. Wang (NAOC, CAS), Q. Y. Wu (NAOC, CAS), X. P. Xu (NAOC, CAS), Y. F. Xu (NAOC, CAS), M. Zhang (NAOC, CAS), W. D. Zhang (NAOC, CAS), Y. J. Zhang (THU), D. H. Zhao (NAOC, CAS) and W. Yuan (NAOC, CAS), on behalf of the LEIA and Einstein Probe team
on 29 Nov 2023; 09:00 UT
Distributed as an Instant Email Notice Transients
Credential Certification: Yuan Liu (liuyuan@bao.ac.cn)
Subjects: X-ray, Transient, Variables
We report on a new bright X-ray flare detected by LEIA (Lobster Eye Imager for Astronomy). The position of the LEIA source is R.A. = 94.721 deg, DEC = -72.04 deg with an uncertainty of 1.4 arcmin (radius, 90%C.L. statistical and systematic). The source was detected by LEIA at 2023-11-27T16:25:29 with a flux of ~1.3e-10 erg/s/cm2 in 0.5-4 keV.
There is an eruptive variable star (AO Men) within the error circle at a separation of 1.9 arcmin with a ROSAT archived flux of 9.99e-12 erg/s/cm2, which is fainter than the flux detected by LEIA by a factor of 10. AO Men is a K4 star in the Solar neighbourhood at a distance of ~39 pc. Considering the spatial association and highly variable nature of this star, although there are very few records of previous outbursts from it, we tend to suggest that this bright X-ray flare is most likely associated with AO Men. Yet an origin of an unrelated new X-ray transient cannot be fully ruled out at the moment. Multi-wavelength follow-up observations are encouraged.
LEIA (Zhang et al. 2022, ApJL, 941, 2) is a soft X-ray Lobster-eye imager (0.5 - 4.0keV) with a FoV of 340 square degrees aboard the experimental satellite SATech-01 of the CAS, launched on July 27, 2022. The above result is preliminary and the final result will be published elsewhere.
