MAXI/GSC discovery of a new X-ray transient MAXI J1348-630
ATel #12425; F. Yatabe (RIKEN), H. Negoro, M. Nakajima, A. Sakamaki, W. Maruyama, M. Aoki, K. Kobayashi (Nihon U.), T. Mihara, S. Nakahira, Y. Takao, M. Matsuoka (RIKEN), T. Sakamoto, M. Serino, S. Sugita, T. Hashimoto, A. Yoshida (AGU), N. Kawai, M. Sugizaki, Y. Tachibana, K. Morita (Tokyo Tech), S. Ueno, H. Tomida, M. Ishikawa, Y. Sugawara, N. Isobe, R. Shimomukai, T. Midooka (JAXA), Y. Ueda, A. Tanimoto, T. Morita, S. Yamada, S. Ogawa (Kyoto U.), Y. Tsuboi, W. Iwakiri, R. Sasaki, H. Kawai, T. Sato (Chuo U.), H. Tsunemi, T. Yoneyama, K. Asakura, S. Ide (Osaka U.), M. Yamauchi, K. Hidaka, S. Iwahori (Miyazaki U.), T. Kawamuro (NAOJ), K. Yamaoka (Nagoya U.), M. Shidatsu (Ehime U.), and Y. Kawakubo (LSU)
on 26 Jan 2019; 05:18 UT
Distributed as an Instant Email Notice Transients
Credential Certification: Hitoshi Negoro (negoro@phys.cst.nihon-u.ac.jp)
Subjects: X-ray, Transient
Referred to by ATel #: 12430, 12434, 12439, 12441, 12447, 12448, 12456, 12457, 12470, 12477, 12480, 12491, 12497, 12505, 12520, 12829, 12838, 13188, 13451, 13459, 13465, 13539, 13710, 13994, 14016
The MAXI/GSC nova alert system triggered on an uncatalogued X-ray transient source at 03:16 UT on 2019 January 26. Assuming that the source flux was constant over four transits from 21:05 on Jan. 25 to 03:16 on Jan. 26, we obtain the source position at
(R.A., Dec) = (207.053 deg, -63.068 deg) = (13 48 12, -63 04 04) (J2000)
with a statistical 90% C.L. elliptical error region with long and short radii of 0.42 deg and 0.34 deg, respectively. The roll angle of the long axis from the north direction is 36.0 deg counterclockwise. There is an additional systematic uncertainty of 0.1 deg (90% containment radius). The X-ray flux averaged over the scans was 47 +- 8 mCrab (4.0-10.0keV, 1 sigma error).
The source flux has been increasing since 21:05 on January 25, and judging from color images of the MAXI nova-alert system the source spectrum is likely hard. Since there is no known bright X-ray source in the error region above and the source is located on the galactic plane at (l, b) = (309.3, -0.9), the source is very likely a new X-ray nova, and we name the source MAXI J1348-630.
Followup observations are strongly encouraged to reveal the nature of the source.
Nova alert information of MAXI J1348-630
