TNS Classification Report No. 23756 [ 2026TNSCR2165....1T ]
Date Received (UTC): 2026-05-18 10:46:14 Sender: Benny Trakhtenbrot
Group: SDSS
Benny Trakhtenbrot (Tel Aviv U.), Franz Bauer (U. de Tarapaca), Paula Silva (PUC Chile, U. de Tarapaca), Jessie Runnoe (Vanderbilt), Andrea Merloni (MPE), John Donor (Texas Christian U.), Sean Morrison (U. of Illinois), Mike Eracleous (Penn State), Mirko Krumpe (AIP), Kriti Kamal Gupta (AIP), Grisha Zeltyn (Tel Aviv U.), Anton M. Koekemoer (STScI), Thomas Kupfer (U. of Hamburg), Donald P. Schneider (Penn State), Juna A. Kollmeier (Carnegie Observatories), Scott Anderson (U. of Washington), Roberto Assef (U. Diego Portales), William Nielsen Brandt (Penn State), Igor Chilingarian (SAO/CfA), Xinyu Dai (U. of Oklahoma), Megan Davis (U. of Connecticut), Boris Gaensicke (U. of Warwick), Lorena Hernández-García (U. Diego Portales), Chenxu Liu (Yunnan U.), Devika Mukhi Nilo (PUC Chile), Margarita Pereyra (UNAM Ensenada), Mara Salvato (MPE), José Sánchez-Gallego (U. of Washington), Axel Schwope (IAP), Guy Stringfellow (U. of Colorado, Boulder), Hector Hernandez Toledo (UNAM), Qian Yang (CfA) report/s a classification of object: AT 2025alls
Type: AGNRedshift: 0.2697
Remarks: The new SDSS-V spectrum (obtained through the new ToO capability) shows a significantly bluer continuum compared to the archival SDSS spectrum of this X-ray emitting AGN, and exhibits a substantial increase in the flux of broad Balmer lines. These spectral changes resemble what is seen in changing-look AGN. We therefore classified AT 2025alls as an AGN undergoing a significant brightening event.
The following Classification spectrum was provided:
Obsdate: 2021-01-13 00:00:00
Instrument: BOSS
Telescope: Sloan Digital Sky Survey
Remarks: SDSS/DR19 eFEDS spectrum
Details of the object and its spectra can be viewed here: https://sandbox.wis-tns.org/object/2025alls
Date Received (UTC): 2026-05-18 10:46:14 Sender: Benny Trakhtenbrot
Group: SDSS
Benny Trakhtenbrot (Tel Aviv U.), Franz Bauer (U. de Tarapaca), Paula Silva (PUC Chile, U. de Tarapaca), Jessie Runnoe (Vanderbilt), Andrea Merloni (MPE), John Donor (Texas Christian U.), Sean Morrison (U. of Illinois), Mike Eracleous (Penn State), Mirko Krumpe (AIP), Kriti Kamal Gupta (AIP), Grisha Zeltyn (Tel Aviv U.), Anton M. Koekemoer (STScI), Thomas Kupfer (U. of Hamburg), Donald P. Schneider (Penn State), Juna A. Kollmeier (Carnegie Observatories), Scott Anderson (U. of Washington), Roberto Assef (U. Diego Portales), William Nielsen Brandt (Penn State), Igor Chilingarian (SAO/CfA), Xinyu Dai (U. of Oklahoma), Megan Davis (U. of Connecticut), Boris Gaensicke (U. of Warwick), Lorena Hernández-García (U. Diego Portales), Chenxu Liu (Yunnan U.), Devika Mukhi Nilo (PUC Chile), Margarita Pereyra (UNAM Ensenada), Mara Salvato (MPE), José Sánchez-Gallego (U. of Washington), Axel Schwope (IAP), Guy Stringfellow (U. of Colorado, Boulder), Hector Hernandez Toledo (UNAM), Qian Yang (CfA) report/s a classification of object: AT 2025alls
Type: AGNRedshift: 0.2697
Remarks: The new SDSS-V spectrum (obtained through the new ToO capability) shows a significantly bluer continuum compared to the archival SDSS spectrum of this X-ray emitting AGN, and exhibits a substantial increase in the flux of broad Balmer lines. These spectral changes resemble what is seen in changing-look AGN. We therefore classified AT 2025alls as an AGN undergoing a significant brightening event.
The following Classification spectrum was provided:
Obsdate: 2021-01-13 00:00:00
Instrument: BOSS
Telescope: Sloan Digital Sky Survey
Remarks: SDSS/DR19 eFEDS spectrum
Details of the object and its spectra can be viewed here: https://sandbox.wis-tns.org/object/2025alls