DRAFT
2025-08-12 15:15:55
Type: Object/s-Discovery/Classification
Bibcode: 2025TNSAN.254....1G
AT2025tpu: Possible very young supernova in IC4769 at 58 Mpc
Authors: P.J. Groot (Radboud/UCT/SAAO), E. Zimmerman (Weizmann), H. Tranin (Barcelona), J. van Roestel (Amsterdam), P.M. Vreeswijk (Radboud), S. Bloemen (Radboud), J. Paice (Durham), F. Stoppa (Oxford), G. Ramsay (Armagh/Warwick)
Source Group: BlackGEM
Keywords: Optical, Photometry, Supernova, Time-domain, Transient
Abstract:
A very young supernova candidate, AT2025tpu, is reported by the BlackGEM consortium in the Seyfert 2 galaxy IC 4769 at 58 Mpc. The transient was first detected at q=19.25 and confirmed to be brightening during the night. A one-day upper limit of q >19.68 is set the previous nights with non-detections in multiple images. IC 4769 is also the host galaxy of SN2004ac, a type Ia supernova.

The BlackGEM consortium reports the detection of BGEM J184740.50-630939.4 /AT2025tpu at RA,DEC (ICRS) = 281.918767 -63.160972 = 
=18:47:40.504 -63:09:39.50. The transient was first detected at 2025-08-12 00:34:44 UT at q=19.25 +/- 0.07, and subsequently brightened on a second visit at 2025-08-12 01:50:14 to q=19.00 +-/- 0.09. The last non-detection of the source was on 2025-08-11 03:21:54 UT at a 6-sigma limit for transients of q>19.68 as the last of four multi-band visits during that night, where the source was detected in none of the images. 

AT2025tpu is located in the outskirts of the Seyfert 2 galaxy IC 4769 at a distance of 58 Mpc and at 28" from the center of IC4769 in an uncrowded region of the galaxy. Adopting the distance of IC4769 for the transient, it is currently at an absolute magnitude of -14.8. We note that IC4769 was also host to SN2004ac, a Type Ia supernova.

Spectroscopic identification of this young transient is requested. 

BlackGEM is designed, built and operated at the ESO La Silla Observatory, Chile by a consortia of universities and institutes, including
Radboud, NOVA, KU Leuven, Armagh, Barcelona, Tel Aviv, Weizmann, HUJI, Potsdam, Hamburg, DTU Space, Manchester, Warwick, Durham, UC Davis, TexasTech, LCO, Valparaiso.


 

Show current TNS values
Catalog Name Reported RA Reported DEC Reported Obj-Type Reported Redshift Host Name Host Redshift Remarks TNS RA TNS DEC TNS Obj-Type TNS Redshift
TNS 2004ac 18:47:43.670 -63:08:54.60 SN Ia IC 4769 18:47:43.670 -63:08:54.60 SN Ia
TNS 2025tpu 18:47:40.504 -63:09:39.50 18:47:40.504 -63:09:39.50 SN IIn 0.015

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