https://www.astronomerstelegram.org Request for Observations, from The Astronomer's Telegram en-us https://www.astronomerstelegram.org/?read=17808 F. Casaburo, G. La Mura, C. C. Cheung, and S. Ciprini, on behalf of the Fermi Large Area Telescope Collaboration F. Casaburo, G. La Mura, C. C. Cheung, and 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 ATel17808 The Large Area Telescope (LAT), one of the two instruments on the Fermi Gamma-ray Space Telescope, has observed renewed gamma-ray activity from a source positionally consistent with the compact steep spectrum quasar 3C 138, also known as 4FGL J0521.2+1637 (The Fermi-LAT collaboration 2020, ApJS, 247, 1), with coordinates R.A. ... 2026-05-22T17:01:42-00:00 https://www.astronomerstelegram.org/?read=17801 Danielle Frostig, Viraj Karambelkar, Kishalay De, Tanishk Mohan, Robert Stein, Nathan Lourie, Sam Rose, Rob Simcoe, Mansi Kasliwal Danielle Frostig, Viraj Karambelkar, Kishalay De, Tanishk Mohan, Robert Stein, Nathan Lourie, Sam Rose, Rob Simcoe, Mansi Kasliwal danielle.frostig@cfa.harvard.edu Credentialed by: Danielle Frostig (danielle.frostig@cfa.harvard.edu) The Astronomer's Telegram ATel17801 We report the discovery of a new recurrent nova AT2026lck in the Milky Way, based on data from the Zwicky Transient facility (ZTF, Bellm et al. 2018), the All-sky Automated Survey for Supernovae (ASAS-SN, Kochanek et al. ... 2026-05-14T17:52:10-00:00 https://www.astronomerstelegram.org/?read=17769 F. Casaburo, G. La Mura, and S. Ciprini, on behalf of the Fermi Large Area Telescope Collaboration F. Casaburo, G. La Mura, and 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 ATel17769 The Large Area Telescope (LAT), one of the two instruments on the Fermi Gamma-ray Space Telescope, has observed enhanced gamma-ray activity from a source positionally consistent with the flat spectrum radio quasar 4C +33.06, also known as 4FGL J0304.5+3349 (The Fermi-LAT collaboration 2020, ApJS, 247, 1), with coordinates R.A. ... 2026-04-27T22:02:32-00:00 https://www.astronomerstelegram.org/?read=17766 F. Casaburo, S. Ciprini and G. La Mura, on behalf of the Fermi Large Area Telescope Collaboration F. Casaburo, S. Ciprini and G. La Mura, 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 ATel17766 The Large Area Telescope (LAT), one of the two instruments on the Fermi Gamma-ray Space Telescope, has observed renewed gamma-ray activity from a source positionally consistent with the FSRQ PKS 0235-618, also known as 4FGL J0236.8-6136 (The Fermi-LAT collaboration 2020, ApJS, 247, 1), with coordinates R.A. ... 2026-04-26T16:12:06-00:00 https://www.astronomerstelegram.org/?read=17763 Costantino Sigismondi Costantino Sigismondi sigismondi@icra.it Credentialed by: Costantino Sigismondi (sigismondi@icra.it) The Astronomer's Telegram ATel17763 The active region AR 14419 is a medium size beta-gamma-delta region, at the end of its presence on the solar hemisphere visible from Earth. Its evolution from C-class towards M-class and X-flaring occurred rapidly from 23 April, topping on 24 April with two X2.5 flares, separated by 7 hours. ... 2026-04-24T14:14:32-00:00 https://www.astronomerstelegram.org/?read=17745 J. Hessdoerfer, F. Eppel, M. Kadler, U. Bach, P. Benke, A. Gokus, L. Haury, S. Kim, F. Roesch J. Hessdoerfer, F. Eppel, M. Kadler, U. Bach, P. Benke, A. Gokus, L. Haury, S. Kim, F. Roesch jonas.hessdoerfer@uni-wuerzburg.de Credentialed by: Florian Eppel (florian.eppel@uni-wuerzburg.de) The Astronomer's Telegram ATel17745 We report fast radio flaring of the TeV-detected flat-spectrum radio quasar B2 1420+32 (OQ 334) at high radio frequencies in the 14mm (19 & ndash;25 GHz) and 7mm (36 & ndash;44 GHz) bands, detected through regular observations within the TELAMON program (see Eppel et al. ... 2026-04-08T15:59:16-00:00 https://www.astronomerstelegram.org/?read=17742 S. A. Trushkin, P. G. Tsybulev, N. N. Bursov, A. V. Shevchenko S. A. Trushkin, P. G. Tsybulev, N. N. Bursov, A. V. Shevchenko satr@sao.ru Credentialed by: Sergei Trushkin (satr@sao.ru) The Astronomer's Telegram ATel17742 We carry out the multi-frequency monitoring of the Galactic microquasars with the RATAN-600 radio telescope and on 6 April 2026 detected the giant flare from the microquasar Cygnus X-3 at frequencies 4.7-30 GHz. ... 2026-04-06T10:08:29-00:00