MAXI/GSC detection of a new X-ray nova MAXI J1750-327

ATel #17963; H. Negoro (Nihon U.), S. Kobayashi (Kyoto U.), M. Serino (AGU), M. Nakajima, K. Saito, T. Yokoyama, M. Wada (Nihon U.), T. Mihara, T. Tamagawa, N. Kawai, M. Matsuoka (RIKEN), T. Sakamoto, S. Sugita, Y. Kawakubo, H. Hiramatsu, A. Yoshida (AGU), Y. Tsuboi, Y. Ishihara, H. Ogaki (Chuo U.), M. Shidatsu, C. Kang, M. Uenishi, T. Usuki, S. Yatsuzuka, H. Aoe (Ehime U.), I. Takahashi, Y. Yatsu (Science Tokyo), S. Nakahira, S. Ueno, H. Tomida, M. Kurihara (JAXA), Y. Ueda, K. Fujiwara (Kyoto U.), M. Yamauchi, M. Nishio, C. Hiraizumi (Miyazaki U.), K. Yamaoka (Nagoya U.), M. Sugizaki (Kanazawa U.), W. Iwakiri (Chiba U.), T. Kawamuro (Osaka U.), S. Yamada (Tohoku U), and S. Ogawa (TUS)
on 13 Aug 2026; 08:45 UT
Distributed as an Instant Email Notice Transients
Credential Certification: Hitoshi Negoro (negoro@phys.cst.nihon-u.ac.jp)

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The MAXI/GSC nova alert system triggered on a bright X-ray transient source at 02:41 UT on August 13, 2026. Assuming that the source flux was constant over four transits from 01:09 to 05:48 on August 13, we obtain the source position at

(R.A., Dec) = (267.736 deg, -32.734 deg) = (17 50 56.6, -32 44 02) (J2000)

with a statistical 90% C.L. elliptical error region with long and short radii of 0.17 deg and 0.19 deg, respectively. The roll angle of long axis from the north direction is 15.0 deg counterclockwise. There is an additional systematic uncertainty of 0.1 deg (90% containment radius). The X-ray flux averaged over the scan was 117 +- 12 mCrab (4.0-10.0keV, 1 sigma error).

Since the black hole candidate SLX 1746-331 is clearly out of the error region and there is no known bright catalogued X-ray transient source, we tentatively designate the source MAXI J1750-327. Followup-observations are highly recommend to reveal the nature of the source.

Trigger Information