ATLAS optical counterpart of the black hole X-ray transient MAXI J1750-327 / EP J175003.0-324244
ATel #17977; A. K.H. Kong (NTHU)
on 16 Aug 2026; 10:57 UT
Credential Certification: Albert Kong (akong@phys.nthu.edu.tw)
Subjects: Optical, X-ray, Binary, Black Hole, Transient
Referred to by ATel #: 17978
Following the recent report of the X-ray outburst and the discovery of the optical counterpart of the Galactic black hole X-ray transient MAXI J1750-327 / EP J175003.0-324244 (ATel #17963, #17964, #17971), we searched the ATLAS database to investigate the optical variability. Using the ATLAS forced photometry server (https://fallingstar-data.com/forcedphot/), we extracted the long-term optical light curve of MAXI J1750-327. Based on forced measurements on the difference images, the proposed optical counterpart of MAXI J1750-327 was detected on 2026-08-12 (MJD 61264.957506) by the ATLAS telescope in South Africa. The exposure started at 22:58 (UTC) and the source was detected with a magnitude of 17.52+/-0.08 in the o-filter. The source was not detected before that. This indicates that the optical outburst may precede the X-ray outburst.
Multi-wavelength follow-up observations are encouraged to monitor the source's variability.
ATLAS light curve
