The Astronomer's Telegram: Top ATels

For reporting and commenting upon new observations of astronomical transients by the professional astrophysics community.

ATel 18030: SVOM/ECLAIRs detection of a possible new outburst onset from the black hole 4U 1630-472

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. ...
https://www.astronomerstelegram.org/?read=18030
date: 2026-09-04T13:05:22-00:00
creator: F. Cangemi, S. Le Stum, A. Coleiro, O. Godet, J. Rodriguez, Y.-H. I. Yin, R.-C. Chen, L. Tao, L. Zhang

ATel 18029: Spectroscopic classification of AT 2026aabo as a bright nova in M31

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. ...
https://www.astronomerstelegram.org/?read=18029
date: 2026-09-03T07:45:36-00:00
creator: Shatakshi Chamoli, Judhajeet Basu, Sudhanshu Barway, G. C. Anupama, Tanishk Mohan, Aditya Pawan Saikia, Vishwajeet Swain, Sameer Patil, Varun Bhalerao, Srikanth Bandari

ATel 18028: NuSTAR detection of shock-powered X-rays from Nova Sagittae 2026 = V488 Sge

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). ...
https://www.astronomerstelegram.org/?read=18028
date: 2026-09-02T19:29:39-00:00
creator: 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

ATel 18027: AT 2026aabo (ZTF26abramlb, ATLAS26kqn): a bright nova candidate in M31

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. ...
https://www.astronomerstelegram.org/?read=18027
date: 2026-09-02T11:55:55-00:00
creator: 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

ATel 18026: Insight-HXMT observations of a soft X-ray flare and a possible QPO-type transition in MAXI J1750-327 / EP260812c (Format Corrected)

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). ...
https://www.astronomerstelegram.org/?read=18026
date: 2026-09-01T13:41:04-00:00
creator: 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

ATel 18025: XMM-Newton detection of a high flux state in the HMXRB IGR J13020-6359

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. ...
https://www.astronomerstelegram.org/?read=18025
date: 2026-09-01T10:23:44-00:00
creator: Robbie Webbe, Natalie A. Webb, Erwan Quintin, Laurent Michel

ATel 18024: Insight-HXMT observations of a soft X-ray flare and a possible QPO-type transition in MAXI J1750-327

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). ...
https://www.astronomerstelegram.org/?read=18024
date: 2026-09-01T02:15:25-00:00
creator: 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

ATel 18023: SRG/ART-XC detection of the new outburst of XTE J1637-498

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''). ...
https://www.astronomerstelegram.org/?read=18023
date: 2026-08-31T19:02:04-00:00
creator: I. Mereminskiy, A. Semena, A. Lutovinov, S. Molkov, A. Tkachenko

ATel 18022: Follow-up spectroscopic observations of Nova Sge 2026 (V488 Sge) with WHUT

Nova Sge 2026 (V488 Sge) was discovered by the NMW-TexasTech survey on 2026-08-25.12 UT (ATel #18009). Follow-up spectroscopic observations were conducted, as reported in ATel #18008 and ATel #18012, confirming it as a Fe II-type nova. ...
https://www.astronomerstelegram.org/?read=18022
date: 2026-08-31T12:02:09-00:00
creator: Sai-En Xu, Yi-Fei Qu, Bei You, on behalf of the Wuhan University One-Meter Optical Telescope team.

ATel 18021: The Fast Nova Sge 2026 (V0488 Sge) from photospheric to nebular regime in four days

The Nova appeared in Sagitta on August 25.12 UT has been already presented in ATel#18008, ATel#18009, ATel#18012, and ATel#18014. We observed the Nova at the 122 cm Galileo telescope of Asiago during the third Summer Asiago School for Young Astronomers with Galileo Observations (ASYAGO) of 24-29 August 2026. ...
https://www.astronomerstelegram.org/?read=18021
date: 2026-08-30T15:22:50-00:00
creator: Paolo Ochner, Costantino Sigismondi, Andrea Reguitti, Alessandro Siviero, Valerio Nobile, Andrea Farina