https://www.astronomerstelegram.org Blazar, from The Astronomer's Telegram en-us https://www.astronomerstelegram.org/?read=17835 Yuhua Yao, Justin Vandenbroucke for the IceCube Collaboration Yuhua Yao, Justin Vandenbroucke for the IceCube Collaboration justin.vandenbroucke@wisc.edu Credentialed by: Justin Vandenbroucke (justin.vandenbroucke@wisc.edu) The Astronomer's Telegram ATel17835 The IceCube Collaboration (http://icecube.wisc.edu/) reports: IceCube has performed a search for track-like muon neutrino events arriving from the direction of the flat-spectrum radio quasar (FSRQ) OQ 334 (B2 1420+326). ... 2026-06-06T21:42:20-00:00 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=17821 Sandeep Kumar Mondal, Avik Kumar Das ), Amar Deo Chandra Sandeep Kumar Mondal, Avik Kumar Das ), Amar Deo Chandra sandeep@sjtu.edu.cn Credentialed by: Amar Deo Chandra (amar.deo.chandra@gmail.com) The Astronomer's Telegram ATel17821 The Large Area Telescope (LAT), one of the two instruments on the Fermi Gamma-ray Space Telescope, has observed enhanced gamma-ray flaring activity from a source positionally consistent with the flat-spectrum radio quasar (FSRQ) OQ 334 (B2 1420+326), also known as 4FGL J1422.5+3223 (Abdollahi et al., Fermi Large Area Telescope Fourth Source Catalog, ApJS, 247(1):33, 2020). ... 2026-05-29T12:51:57-00:00 https://www.astronomerstelegram.org/?read=17812 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 ATel17812 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 flat spectrum radio quasar ON 393, also known as 4FGL J1257.8+3228 (The Fermi-LAT collaboration 2020, ApJS, 247, 1), with radio coordinates R.A. ... 2026-05-25T18:04:42-00:00 https://www.astronomerstelegram.org/?read=17802 Amy Furniss for the VERITAS Collaboration Amy Furniss for the VERITAS Collaboration afurniss@ucsc.edu Credentialed by: Amy Furniss (afurniss@ucsc.edu) The Astronomer's Telegram ATel17802 The flat spectrum radio quasar (FSRQ) B2 1420+32 (also known as 4FGL J1422.5+3223, OQ 334) at z = 0.682 (Hewett & Wild 2010, MNRAS, 405, 2302) is a known very high-energy (VHE; E > 100 GeV) gamma-ray emitter. ... 2026-05-15T01:44:49-00:00 https://www.astronomerstelegram.org/?read=17795 Grishina T. S., Larionova E. G., Troitskiy I. S., Shishkina E. V., Savchenko S. S. Grishina T. S., Larionova E. G., Troitskiy I. S., Shishkina E. V., Savchenko S. S. savchenko.s.s@gmail.com Credentialed by: Sergey Savchenko (savchenko.s.s@gmail.com) The Astronomer's Telegram ATel17795 We report an ongoing optical flare of the blazar B21420+32 (z=0.681). This source is regularly monitored in the framework of the GASP/WEBT project (WEBT; https://www.oato.inaf.it/blazars/webt/). ... 2026-05-12T09:57:57-00:00 https://www.astronomerstelegram.org/?read=17792 L. Carrasco, G. Escobedo, L. Felix, A. Porras, E. Recillas; L. Carrasco, G. Escobedo, L. Felix, A. Porras, E. Recillas; Carrasco@inaoep.mx Credentialed by: LUIS CARRASCO (carrasco@inaoep.mx) The Astronomer's Telegram ATel17792 We report on an ongoing Giant NIR flare of the intermediate redshift (z=0.682) Blazar [HB89]1420+326, We observed the source at NIR wavelengths from May 6th to May 9th,2026 (JD 2461166 to JD2461169), we found the source with monotonically increasing NIR fluxes in this lapse. ... 2026-05-11T04:47:23-00:00 https://www.astronomerstelegram.org/?read=17790 F. Giacchino and G. La Mura, on behalf of the Fermi Large Area Telescope Collaboration F. Giacchino and G. La Mura, on behalf of the Fermi Large Area Telescope Collaboration federica.giacchino@roma2.infn.it Credentialed by: Federica Giacchino (federica.giacchino@roma2.infn.it) The Astronomer's Telegram ATel17790 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 flat spectrum radio quasar (FSRQ) OQ 334, also known as B2 1420+32, GB2 1420+326 and 4FGL J1422.5+3223 (Abdollahi et al. ... 2026-05-10T17:01:00-00:00 https://www.astronomerstelegram.org/?read=17787 Alessandro Marchini ; Leonardo Stiaccini, Gaia Verna, University of Siena - Italy); Alessandro Nastasi, Sabrina Masiero, Alessio Squilloni ; Giacomo Bonnoli . Alessandro Marchini ; Leonardo Stiaccini, Gaia Verna, University of Siena - Italy); Alessandro Nastasi, Sabrina Masiero, Alessio Squilloni ; Giacomo Bonnoli . gaia.verna@unisi.it Credentialed by: Gaia Verna (gaia.verna@unisi.it) The Astronomer's Telegram ATel17787 During the last nights, we observed an enhanced optical activity of the BL Lac S5 1803+784 (R.A. = 270.19035 deg, Decl. = +78.46778 deg (J2000; Johnston et al. ... 2026-05-09T22:16:38-00:00 https://www.astronomerstelegram.org/?read=17786 F. Giacchino and G. La Mura , on behalf of the Fermi Large Area Telescope Collaboration F. Giacchino and G. La Mura , on behalf of the Fermi Large Area Telescope Collaboration federica.giacchino@roma2.infn.it Credentialed by: Federica Giacchino (federica.giacchino@roma2.infn.it) The Astronomer's Telegram ATel17786 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 (Abdollahi et al. ... 2026-05-09T20:28:59-00:00