https://www.astronomerstelegram.org For reporting and commenting upon new observations of astronomical transients by the professional astrophysics community. en-us https://www.astronomerstelegram.org/?read=18034 Maxime Parra, Pierre-Olivier Petrucci, Stefano Bianchi, Floriane Cangemi, Alessio Marino, Poshak Gandhi, Megumi Shidatsu, et al. Maxime Parra, Pierre-Olivier Petrucci, Stefano Bianchi, Floriane Cangemi, Alessio Marino, Poshak Gandhi, Megumi Shidatsu, et al. maxime.parrastro@gmail.com Credentialed by: Maxime Parra (maxime.parra@univ-grenoble-alpes.fr) The Astronomer's Telegram ATel18034 We report on a follow-up NuSTAR exposure on the Transient Black Hole LMXB candidate 4U 1630-47, obtained as part of an XMM-NuSTAR large program, following the detection of the source by SVOM (Atel #18030). ... 2026-09-07T18:27:22-00:00 https://www.astronomerstelegram.org/?read=18033 M. Mugrauer, L. Maul, and P. Rajkumari M. Mugrauer, L. Maul, and P. Rajkumari markus@astro.uni-jena.de Credentialed by: Markus Mugrauer (markus@astro.uni-jena.de) The Astronomer's Telegram ATel18033 We carried out follow-up imaging and spectroscopic observations of Nova Sagittae 2026 (ATel #18009) on 1 and 2 September 2026 at the University Observatory Jena. ... 2026-09-07T12:42:45-00:00 https://www.astronomerstelegram.org/?read=18032 F. Casaburo, S. Ciprini on behalf of the Fermi Large Area Telescope Collaboration F. Casaburo, S. Ciprini on behalf of the Fermi Large Area Telescope Collaboration fausto.casaburo@roma2.infn.it Credentialed by: Giovanni La Mura (giovanni.lamura@inaf.it) The Astronomer's Telegram ATel18032 The Large Area Telescope (LAT), one of the two instruments on the Fermi Gamma-ray Space Telescope, has observed gamma-ray activity from a source positionally consistent with the Seyfert 1 galaxy PKS 0521-36, also known as 4FGL J0522.9-3628 (Abdollahi et al. ... 2026-09-06T20:43:58-00:00 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=18030 F. Cangemi, S. Le Stum, A. Coleiro, O. Godet, J. Rodriguez, Y.-H. I. Yin, R.-C. Chen, L. Tao, L. Zhang F. Cangemi, S. Le Stum, A. Coleiro, O. Godet, J. Rodriguez, Y.-H. I. Yin, R.-C. Chen, L. Tao, L. Zhang cangemi@apc.in2p3.fr Credentialed by: Floriane Cangemi (cangemi@apc.in2p3.fr) The Astronomer's Telegram ATel18030 On 2026 September 2 at 01:59:31.116 UT, the onboard trigger software of the SVOM/ECLAIRs telescope (4-150 keV) detected and localized a source at R.A. = 248.506 deg and Dec. ... 2026-09-04T13:05:22-00:00 https://www.astronomerstelegram.org/?read=18029 Shatakshi Chamoli, Judhajeet Basu, Sudhanshu Barway, G. C. Anupama, Tanishk Mohan, Aditya Pawan Saikia, Vishwajeet Swain, Sameer Patil, Varun Bhalerao, Srikanth Bandari Shatakshi Chamoli, Judhajeet Basu, Sudhanshu Barway, G. C. Anupama, Tanishk Mohan, Aditya Pawan Saikia, Vishwajeet Swain, Sameer Patil, Varun Bhalerao, Srikanth Bandari shatakshi.chamoli@iiap.res.in Credentialed by: Judhajeet Basu (judhajeet.basu@iiap.res.in) The Astronomer's Telegram ATel18029 We report the spectroscopic classification of AT 2026aabo as a very bright and slowly evolving nova in M31. This transient was first discovered on 2026-08-29T09:28:57 by ZTF Collaboration and reported on TNS at 18.57 mags in the ZTF-g band. ... 2026-09-03T07:45:36-00:00 https://www.astronomerstelegram.org/?read=18028 Kirill Sokolovsky, Katie Barnhart, Darien Perla, Pragati Acharya, John Worley, Anthony Pearce, Vallia Antoniou, Elias Aydi, Laura Chomiuk, Peter Craig, Isabella Molina, Jennifer Sokoloski, Justin Linford, Koji Mukai Kirill Sokolovsky, Katie Barnhart, Darien Perla, Pragati Acharya, John Worley, Anthony Pearce, Vallia Antoniou, Elias Aydi, Laura Chomiuk, Peter Craig, Isabella Molina, Jennifer Sokoloski, Justin Linford, Koji Mukai kirx@kirx.net Credentialed by: Kirill Sokolovsky (kirx@scan.sai.msu.ru) The Astronomer's Telegram ATel18028 Nova Sagittae 2026 (V488 Sge, PNV J19450648+1822422) was discovered on its rise to optical peak by the NMW-TexasTech survey at 2026-08-25.1278 UTC having an unfiltered magnitude 9.0 (CBET #5729, ATel #18008, #18009, #18012, #18014, #18021, #18022). ... 2026-09-02T19:29:39-00:00 https://www.astronomerstelegram.org/?read=18027 I. Perez-Fournon, F. Poidevin, A. Lopez-Oramas, D. Aguado, N. Abreu Garcia, D. Cano-Morales, I. Correa-Plasencia, A. E. Hernandez-Diaz, E. Lekaroz-Urriza, M. Magdalena-Rodriguez, M. Quintana-Ansaldo, D. Rodriguez-Fernandez, and J. Uribarri-Dermit I. Perez-Fournon, F. Poidevin, A. Lopez-Oramas, D. Aguado, N. Abreu Garcia, D. Cano-Morales, I. Correa-Plasencia, A. E. Hernandez-Diaz, E. Lekaroz-Urriza, M. Magdalena-Rodriguez, M. Quintana-Ansaldo, D. Rodriguez-Fernandez, and J. Uribarri-Dermit ipf@iac.es Credentialed by: Ismael Perez-Fournon (ipf@iac.es) The Astronomer's Telegram ATel18027 We report ATLAS forced photometry of the bright nova candidate AT 2026aabo (ZTF26abramlb, ATLAS26kqn). This transient was discovered by Anirudh Salgundi on behalf of ZTF (TNS Astronomical Transient Report No. ... 2026-09-02T11:55:55-00:00 https://www.astronomerstelegram.org/?read=18026 B. Y. Chen, W. Z. Li, Q. C. Shui, Y. P. Chen, S. Zhang, S. N. Zhang, H. Feng, L. Tao, L. Zhang, S. M. Jia, X. B. Li, F. J. Lu, L. M. Song, S. J. Zheng, C. K. Li, Z. X. Li, G. L. Huang, Q. C. Zhao, on behalf of the Insight-HXMT team B. Y. Chen, W. Z. Li, Q. C. Shui, Y. P. Chen, S. Zhang, S. N. Zhang, H. Feng, L. Tao, L. Zhang, S. M. Jia, X. B. Li, F. J. Lu, L. M. Song, S. J. Zheng, C. K. Li, Z. X. Li, G. L. Huang, Q. C. Zhao, on behalf of the Insight-HXMT team bychen@ihep.ac.cn Credentialed by: Yu-Peng Chen (chenyp@ihep.ac.cn) The Astronomer's Telegram ATel18026 MAXI J1750-327 / EP260812c / EP J175003.0-324244 was discovered by MAXI/GSC and Einstein Probe (ATels #17963 and #17964) and was subsequently identified as a black-hole X-ray binary candidate based on its X-ray spectral and timing properties (ATels #17969 and #17974). ... 2026-09-01T13:41:04-00:00 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