https://www.astronomerstelegram.org Black Hole, from The Astronomer's Telegram en-us https://www.astronomerstelegram.org/?read=17836 S. A. Trushkin, P. G. Tsybulev, N. N. Bursov, S. A. Trushkin, P. G. Tsybulev, N. N. Bursov, sergei.trushkin@gmail.com Credentialed by: Sergei Trushkin (satr@sao.ru) The Astronomer's Telegram ATel17836 We carry out the multi-frequency monitoring of the Galactic microquasars with the RATAN-600 radio telescope on 10 January, 6 and 26 April, and now on 6 June 2026 we detected the giant flares from the X-ray and Gamma-ray binary, microquasar Cygnus X-3 at frequencies 1.45 - 30 GHz (see ATel #17742). ... 2026-06-07T09:42:51-00:00 https://www.astronomerstelegram.org/?read=17827 L. Carrasco, A. Porras,G. Escobedo, E. Recillas, L. Felix L. Carrasco, A. Porras,G. Escobedo, E. Recillas, L. Felix Carrasco@inaoep.mx Credentialed by: LUIS CARRASCO (carrasco@inaoep.mx) The Astronomer's Telegram ATel17827 We report on a recent fast NIR flare of the Blazar CGRaBSJ1257+3229, also known as QSO B1255+32 cross correlated with the gamma-ray source 2FGLJ1258.2+3231. ... 2026-06-02T16:06:47-00:00 https://www.astronomerstelegram.org/?read=17820 S. Le Stum, F. Cangemi, A. Coleiro, S. Guillot, L. Zhang S. Le Stum, F. Cangemi, A. Coleiro, S. Guillot, L. Zhang lestum@apc.in2p3.fr Credentialed by: Floriane Cangemi (cangemi@apc.in2p3.fr) The Astronomer's Telegram ATel17820 We report a spectral softening of the microquasar Cygnus X-3 detected on 2026 May 27 by the ECLAIRs coded-mask instrument onboard the SVOM mission. The long-term ECLAIRs light curve had shown a progressive hardening of the source from 2026 March 30 until 2026 May 12. ... 2026-05-29T07:12:51-00:00 https://www.astronomerstelegram.org/?read=17814 K. Tsubono, K. Asuma, K. Niinuma, K. Takefuji and T. Daishido K. Tsubono, K. Asuma, K. Niinuma, K. Takefuji and T. Daishido tsubono@phys.s.u-tokyo.ac.jp Credentialed by: Kimio Tsubono (tsubono@phys.s.u-tokyo.ac.jp) The Astronomer's Telegram ATel17814 We report the apparent fading of the recent radio rebrightening activity from Cygnus X-3 observed with the Nasu radio telescope array at 1.4 GHz, following our previous reports (ATel #17746, #17758). ... 2026-05-26T04:44:32-00:00 https://www.astronomerstelegram.org/?read=17771 Oluwashina Adegoke, Javier Garcia, Fiona Harrison, Karl Forster Oluwashina Adegoke, Javier Garcia, Fiona Harrison, Karl Forster oadegoke@caltech.edu Credentialed by: Oluwashina Adegoke (oadegoke@caltech.edu) The Astronomer's Telegram ATel17771 The onset of a new outburst from the black hole X-ray binary GS 1354-64 was triggered by the MAXI/GSC nova alert system on 2025 December 25 (ATel #17563). ... 2026-05-01T04:43:02-00:00 https://www.astronomerstelegram.org/?read=17758 K. Tsubono, K. Asuma, K. Niinuma, K. Takefuji and T. Daishido K. Tsubono, K. Asuma, K. Niinuma, K. Takefuji and T. Daishido tsubono@phys.s.u-tokyo.ac.jp Credentialed by: Kimio Tsubono (tsubono@phys.s.u-tokyo.ac.jp) The Astronomer's Telegram ATel17758 Following our report of the recent 1.4 GHz radio flare from Cygnus X-3 (ATel #17746), we continued daily monitoring observations with the Nasu radio telescope array. ... 2026-04-19T01:18:15-00:00 https://www.astronomerstelegram.org/?read=17746 K. Tsubono, K. Asuma, K. Niinuma, K. Takefuji and T. Daishido K. Tsubono, K. Asuma, K. Niinuma, K. Takefuji and T. Daishido tsubono@phys.s.u-tokyo.ac.jp Credentialed by: Kimio Tsubono (tsubono@phys.s.u-tokyo.ac.jp) The Astronomer's Telegram ATel17746 Following the report of a new radio outburst of Cygnus X-3 at frequencies above 4 GHz by the RATAN-600 team (ATel #17741), we carried out monitoring observations with the Nasu radio telescope array at 1.4 GHz. ... 2026-04-10T03:54:18-00:00