https://www.astronomerstelegram.org Star, from The Astronomer's Telegram en-us https://www.astronomerstelegram.org/?read=18031 M. Nakajima, H. Negoro, M. Serino, S. Sugita, K. Saito, T. Yokoyama, M. Wada, T. Mihara, T. Tamagawa, N. Kawai, M. Matsuoka, T. Sakamoto, Y. Kawakubo, H. Hiramatsu, A. Yoshida, Y. Tsuboi, Y. Ishihara, H. Ogaki, M. Shidatsu, C. Kang, M. Uenishi, T. Usuki, S. Yatsuzuka, H. Aoe, I. Takahashi, Y. Yatsu, S. Nakahira, S. Ueno, H. Tomida, M. Kurihara, Y. Ueda, K. Fujiwara, S. Kobayashi, M. Yamauchi, M. Nishio, C. Hiraizumi, K. Yamaoka, M. Sugizaki, W. Iwakiri, T. Kawamuro, S. Yamada, S. Ogawa M. Nakajima, H. Negoro, M. Serino, S. Sugita, K. Saito, T. Yokoyama, M. Wada, T. Mihara, T. Tamagawa, N. Kawai, M. Matsuoka, T. Sakamoto, Y. Kawakubo, H. Hiramatsu, A. Yoshida, Y. Tsuboi, Y. Ishihara, H. Ogaki, M. Shidatsu, C. Kang, M. Uenishi, T. Usuki, S. Yatsuzuka, H. Aoe, I. Takahashi, Y. Yatsu, S. Nakahira, S. Ueno, H. Tomida, M. Kurihara, Y. Ueda, K. Fujiwara, S. Kobayashi, M. Yamauchi, M. Nishio, C. Hiraizumi, K. Yamaoka, M. Sugizaki, W. Iwakiri, T. Kawamuro, S. Yamada, S. Ogawa nakajima.motoki@nihon-u.ac.jp Credentialed by: Motoki Nakajima (nakajima.motoki@nihon-u.ac.jp) The Astronomer's Telegram ATel18031 The MAXI/GSC nova alert system triggered an X-ray transient source at (R.A., Dec) = (128 deg, -43 deg) on August 29, 2026 (MJD 61281). Since the source was observed during high-background orbits in late August, its position could not be precisely determined from those scans. ... 2026-09-06T08:02:19-00:00 https://www.astronomerstelegram.org/?read=18025 Robbie Webbe, Natalie A. Webb, Erwan Quintin, Laurent Michel Robbie Webbe, Natalie A. Webb, Erwan Quintin, Laurent Michel robbie.webbe@cnrs.fr Credentialed by: Robbie Webbe (robbie.webbe@cnrs.fr) The Astronomer's Telegram ATel18025 We report the detection of X-ray brightening from the source IGR J13020-6359 with the XMM-Newton X-ray telescope in the energy range 0.2-12.0 keV. On 7th August 2026 IGR J13020-6359 was observed in the field of view of an XMM-Newton observation, and the long-term variability was assessed using the multi-observatory STONKS pipeline. ... 2026-09-01T10:23:44-00:00 https://www.astronomerstelegram.org/?read=18023 I. Mereminskiy, A. Semena, A. Lutovinov, S. Molkov, A. Tkachenko I. Mereminskiy, A. Semena, A. Lutovinov, S. Molkov, A. Tkachenko i.a.mereminskiy@gmail.com Credentialed by: Sergei Molkov (molkov@hea.iki.rssi.ru) The Astronomer's Telegram ATel18023 During the observations of the Galactic Plane on Aug. 31, 2026, the Mikhail Pavlinsky ART-XC telescope onboard the SRG observatory detected a bright X-ray source at the position of RA, Dec = 249.2598, -49.8590 (estimated 90% containment radius of 10''). ... 2026-08-31T19:02:04-00:00 https://www.astronomerstelegram.org/?read=18020 M. Nakajima, H. Hiramatsu, H. Negoro, K. Saito, T. Yokoyama, M. Wada, T. Mihara, T. Tamagawa, N. Kawai, M. Matsuoka, T. Sakamoto, M. Serino, S. Sugita, Y. Kawakubo, A. Yoshida, Y. Tsuboi, Y. Ishihara, H. Ogaki, M. Shidatsu, C. Kang, M. Uenishi, T. Usuki, S. Yatsuzuka, H. Aoe, I. Takahashi, Y. Yatsu, S. Nakahira, S. Ueno, H. Tomida, M. Kurihara, Y. Ueda, K. Fujiwara, S. Kobayashi, M. Yamauchi, M. Nishio, C. Hiraizumi, K. Yamaoka, M. Sugizaki, W. Iwakiri, T. Kawamuro, S. Yamada, S. Ogawa M. Nakajima, H. Hiramatsu, H. Negoro, K. Saito, T. Yokoyama, M. Wada, T. Mihara, T. Tamagawa, N. Kawai, M. Matsuoka, T. Sakamoto, M. Serino, S. Sugita, Y. Kawakubo, A. Yoshida, Y. Tsuboi, Y. Ishihara, H. Ogaki, M. Shidatsu, C. Kang, M. Uenishi, T. Usuki, S. Yatsuzuka, H. Aoe, I. Takahashi, Y. Yatsu, S. Nakahira, S. Ueno, H. Tomida, M. Kurihara, Y. Ueda, K. Fujiwara, S. Kobayashi, M. Yamauchi, M. Nishio, C. Hiraizumi, K. Yamaoka, M. Sugizaki, W. Iwakiri, T. Kawamuro, S. Yamada, S. Ogawa nakajima.motoki@nihon-u.ac.jp Credentialed by: Motoki Nakajima (nakajima.motoki@nihon-u.ac.jp) The Astronomer's Telegram ATel18020 The MAXI/GSC nova alert system triggered an alert for an X-ray outburst from the Be/X-ray binary pulsar 1A 0538-66 at 12:35 UT on 2026 August 28 (MJD 61280). ... 2026-08-29T02:00:40-00:00 https://www.astronomerstelegram.org/?read=18011 F. Coti Zelati, A. Marino, G. Illiano, Y. L. Wang, J. H. Wu, H. N. Yang, R. D. Liang, H. W. Pan, N. Rea, H. Feng, L. Tao, H. Sun, W. Yuan, C. Jin, J. U. Ness F. Coti Zelati, A. Marino, G. Illiano, Y. L. Wang, J. H. Wu, H. N. Yang, R. D. Liang, H. W. Pan, N. Rea, H. Feng, L. Tao, H. Sun, W. Yuan, C. Jin, J. U. Ness cotizelati@ice.csic.es Credentialed by: Francesco Coti Zelati (cotizelati@ice.csic.es) The Astronomer's Telegram ATel18011 The intermittent accreting millisecond X-ray pulsar SAX J1748.9-2021, located in the Galactic globular cluster NGC 6440, has undergone six recorded outbursts since its discovery (in 1998, 2001, 2005, 2010, 2015, and a faint event in 2017 lasting only around 13 days, significantly shorter than the typically month-long previous outbursts; e.g., Marino et al. ... 2026-08-26T08:03:43-00:00 https://www.astronomerstelegram.org/?read=18009 Katie Barnhart, Kirill Sokolovsky, Darien Perla, Pragati Acharya, John Worley, Anthony Pearce, Vallia Antoniou, Elias Aydi, Bassam Debs, and Omar Kilo . Katie Barnhart, Kirill Sokolovsky, Darien Perla, Pragati Acharya, John Worley, Anthony Pearce, Vallia Antoniou, Elias Aydi, Bassam Debs, and Omar Kilo . eaydi@ttu.edu Credentialed by: Elias Aydi (eaydi@ttu.edu) The Astronomer's Telegram ATel18009 We report the discovery of the likely Galactic nova NMW-TTU-26bp (PNV J19450648+1822422). The transient was discovered by the NMW-TexasTech survey on 2026-08-25.12 UTC at an unfiltered magnitude of 9.0. ... 2026-08-25T18:04:56-00:00 https://www.astronomerstelegram.org/?read=18006 M. J. Liu, B. T. Wang, Y. L. Hua, and W. D. Zhang on behalf of the Einstein Probe team M. J. Liu, B. T. Wang, Y. L. Hua, and W. D. Zhang on behalf of the Einstein Probe team ep_ta@bao.ac.cn Credentialed by: Yuan Liu (liuyuan@bao.ac.cn) The Astronomer's Telegram ATel18006 We report on the detection of X-ray brighening, likely from 4U 1850-086, by the Wide-field X-ray Telescope (WXT) on board the Einstein Probe (EP) mission. ... 2026-08-25T09:51:13-00:00 https://www.astronomerstelegram.org/?read=18005 A. O. Simon, D. Yu. Rusanova, F.-J. Hambsch, W. Ogloza, N. Karaman, A. Yu. Korosko, P. J. Mikolajczyk, L. Wyrzykowski, K. Kotysz A. O. Simon, D. Yu. Rusanova, F.-J. Hambsch, W. Ogloza, N. Karaman, A. Yu. Korosko, P. J. Mikolajczyk, L. Wyrzykowski, K. Kotysz andrii.o.simon@gmail.com Credentialed by: Andrew Simon (skazhenijandrew@gmail.com) The Astronomer's Telegram ATel18005 Gaia16amd/MASTER OT J203529.80+063652.8/AT 2016dyj was identified by our Outbursts Alerting System as a promising candidate for an SU UMa-type dwarf nova. ... 2026-08-25T09:06:51-00:00 https://www.astronomerstelegram.org/?read=17997 H. Yang,, F. Cangemi, S. Guillot, A. Coleiro, C. Plasse, L. Tao,, L. Zhang H. Yang,, F. Cangemi, S. Guillot, A. Coleiro, C. Plasse, L. Tao,, L. Zhang hyang@irap.omp.eu Credentialed by: Floriane Cangemi (cangemi@apc.in2p3.fr) The Astronomer's Telegram ATel17997 On Tuesday, August 18, 2026, at 14:41:30.099 UT, the onboard trigger software of the SVOM/ECLAIRs telescope (4-150 keV) detected and localized a source at R.A. ... 2026-08-21T13:01:54-00:00 https://www.astronomerstelegram.org/?read=17994 H. Kuramoto, T. Narita, S. Ogawa, T. Hakamata, Y. Kanemaru, A. Miyamoto, Y. Omiya, Y. Uchida, T. Yoneyama, M. Audard, E. Behar, K. Fukushima, H. Iinuma, S. Inoue, Y. Ishihara, S. Ishiwata, C. Kang, M. Kikuchi, T. Kiyomoto, T. Kohmura, Y. Maeda, H. Matsumoto, A. Miyamoto, M. Mizumoto, Y. Motogami, H. Murakami, M. Nobukawa, H. Noda, Y. Sakamoto, M. Shidatsu, H. Takahashi, T. Takagi, S. Takatsuka, F. Takisawa, Y. Terada, Y. Terashima, Y. Tsuboi, H. Uchida, T. Usuki, A. Yoshimoto, M. Yoshimoto, A. Heinrich H. Kuramoto, T. Narita, S. Ogawa, T. Hakamata, Y. Kanemaru, A. Miyamoto, Y. Omiya, Y. Uchida, T. Yoneyama, M. Audard, E. Behar, K. Fukushima, H. Iinuma, S. Inoue, Y. Ishihara, S. Ishiwata, C. Kang, M. Kikuchi, T. Kiyomoto, T. Kohmura, Y. Maeda, H. Matsumoto, A. Miyamoto, M. Mizumoto, Y. Motogami, H. Murakami, M. Nobukawa, H. Noda, Y. Sakamoto, M. Shidatsu, H. Takahashi, T. Takagi, S. Takatsuka, F. Takisawa, Y. Terada, Y. Terashima, Y. Tsuboi, H. Uchida, T. Usuki, A. Yoshimoto, M. Yoshimoto, A. Heinrich ogawa.shoji@rs.tus.ac.jp Credentialed by: Shoji Ogawa (ogawa.shohji@jaxa.jp) The Astronomer's Telegram ATel17994 XRISM/Xtend Transient Search (XTS) detected an X-ray flare from an X-ray source XRISM J0433-6129 on 2026-08-18 TT. The source position is determined to be (R.A., Dec.) = (68.486, -61.493), with a systematic error of & sim;40 arcsec. ... 2026-08-20T13:32:37-00:00