/////////////////////////////////////////////////////////////////////////////////// ATEL #12425 ATEL #12425 Title: MAXI/GSC discovery of a new X-ray transient MAXI J1348-630 Author: 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) Queries: negoro.hitoshi@nihon-u.ac.jp Posted: 26 Jan 2019; 05:18 UT Subjects:X-ray, Transient 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: http://maxi.riken.jp/alert/novae/8509125179/8509125179.htm /////////////////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 23795 SUBJECT: Trigger 885807: Swift detection of MAXI J1348-630 DATE: 19/01/26 11:05:39 GMT FROM: Kim Page at U.of Leicester V. D'Elia (SSDC), A. Y. Lien (GSFC/UMBC) and K. L. Page (U Leicester) report on behalf of the Neil Gehrels Swift Observatory Team: At 10:37:53 UT, the Swift Burst Alert Telescope (BAT) triggered and located MAXI J1348-630 (trigger=885807). Swift slewed immediately to the source. The BAT on-board calculated location is RA, Dec 207.003, -63.265 which is RA(J2000) = 13h 48m 01s Dec(J2000) = -63d 15' 54" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve showed a complex structure. The peak count rate was ~2500 counts/sec (15-350 keV), at ~4 sec after the trigger. The XRT began observing the field at 10:48:44.0 UT, 650.4 seconds after the BAT trigger. The XRT centroided on a cosmic ray, so the automatic position notice is incorrect. There are no other data available at this time. There are no UVOT data available at this time. This source was discovered by MAXI at 03:16 UT this morning (ATel 12425) /////////////////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 23796 SUBJECT: Trigger 885845: A second Swift trigger on MAXI J1348-630 DATE: 19/01/26 12:28:44 GMT FROM: Kim Page at U.of Leicester V. D'Elia (SSDC), A. Y. Lien (GSFC/UMBC) and K. L. Page (U Leicester) report on behalf of the Neil Gehrels Swift Observatory Team: At 12:09:13 UT, the Swift Burst Alert Telescope (BAT) triggered and located MAXI J1348-630 (trigger=885845). Swift was already observing this position from the previous trigger 885807 (GCN 23795) The BAT on-board calculated location is RA, Dec 207.004, -63.270 which is RA(J2000) = 13h 48m 01s Dec(J2000) = -63d 16' 12" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). As is normal for an image trigger, the light-curve showed no significant structure. ///////////////////////////////////////////////////////////////////////////////////