https://www.astronomerstelegram.org Supernovae, from The Astronomer's Telegram en-us https://www.astronomerstelegram.org/?read=17830 A. Nucara, Z. J. Smeaton, A. Simongini, M. Arias, on behalf of the RISE collaboration A. Nucara, Z. J. Smeaton, A. Simongini, M. Arias, on behalf of the RISE collaboration andrea.simongini@inaf.it Credentialed by: Andrea Simongini (andrea.simongini@inaf.it) The Astronomer's Telegram ATel17830 We report radio and millimeter detection of the Type II supernova SN 2007it in NGC 5530 (distance 12.2 Mpc), obtained as part of the Rebrightening in Interacting Supernova Emission (RISE) initiative. ... 2026-06-04T14:00:20-00:00 https://www.astronomerstelegram.org/?read=17803 K. W. Davis, R. J. Foley K. W. Davis, R. J. Foley kywdavis@ucsc.edu Credentialed by: Ryan Foley (foley@ucsc.edu) The Astronomer's Telegram ATel17803 We report the classification of AT 2026mko from spectroscopic observations with the Kast spectrograph on the Shane telescope obtained on 2026 May 15 UT. ... 2026-05-15T16:55:34-00:00 https://www.astronomerstelegram.org/?read=17793 Jenna Karcheski, Kishore C. Patra, Ryan J. Foley Jenna Karcheski, Kishore C. Patra, Ryan J. Foley kcpatra@ucsc.edu Credentialed by: Kishore Patra (kcpatra@ucsc.edu) The Astronomer's Telegram ATel17793 We report the following classifications of optical transients from spectroscopic observations with the Keck Cosmic Web Imager (KCWI) Integral Field Spectrograph. ... 2026-05-11T10:35:07-00:00 https://www.astronomerstelegram.org/?read=17774 S. Lazarevic, K. Rose, R. Alsaberi, Z. Smeaton, on behalf of the RISE collaboration S. Lazarevic, K. Rose, R. Alsaberi, Z. Smeaton, on behalf of the RISE collaboration kovirose@gmail.com Credentialed by: Kovi Rose (kovirose@gmail.com) The Astronomer's Telegram ATel17774 As part of an ongoing study of core-collapse supernovae we observed the Type II supernova SN 2024ggi in NGC 3621 with the Australia Telescope Compact Array (ATCA) on 15 April 2026 09:30-13:30 UTC. ... 2026-05-05T11:36:23-00:00 https://www.astronomerstelegram.org/?read=17757 Kishore C. Patra, Ryan J. Foley, Ravjit Kaur Kishore C. Patra, Ryan J. Foley, Ravjit Kaur kcpatra@ucsc.edu Credentialed by: Kishore Patra (kcpatra@ucsc.edu) The Astronomer's Telegram ATel17757 We report the following classifications of optical transients from spectroscopic observations with the Kast spectrograph on the Shane telescope. The targets were supplied by the Legacy Survey of Space and Time (LSST) and the Zwicky Transient Facility (ZTF). ... 2026-04-18T23:26:48-00:00