AstroNote 2023-257

AT 2023qdi was discovered by Pan-STARRS on UT 2023-07-26 13:52:39 at w-P1 = 20.22 +/- 0.06 and was independently reported to TNS by ATLAS with a first detection on UT 2023-09-07 00:41:53 at orange-ATLAS = 18.956 +/- 0.13. It was classifed as a SN IIn at z = 0.04 by Huber, Fulton, and Moore (SCAT) on 2023-09-18 12:40:16 using UH88 / SNIFS.

We report that SN 2023qdi has also been detected by ZTF (ZTF23aayngri), with a first detection on UT 2023-07-27 11:01:36 at g-ZTF = 20.401 ± 0.244.  Our additional investigation of the light curve using also ATLAS and ASAS-SN forced photometry shows a slow flux rise until UT 2023-09-07 and a fast brightening afterwards with maximim light at about UT 2023-09-14.

Compared to other reported month-long stellar outbursts before the explosion of inter-action powered supernovae, the precursor of SN 2023dpi is relatively bright (g = 20.7 to 19.8) for the SN redshift.

Further follow up is strongly encouraged.

The ZTF light curve is available at the ZTF/LSST brokers, e.g.

https://lasair-ztf.lsst.ac.uk/objects/ZTF23aayngri/

https://alerce.online/object/ZTF23aayngri

https://antares.noirlab.edu/loci/ANT2023ecdiawwydast

https://fink-portal.org/ZTF23aayngri

DESI Legacy Surveys DR10 finding chart:

https://www.legacysurvey.org/viewer?ra=%2010.3247393244%20&dec=%20-14.2…

We acknowledge the use of TNS; ZTF and its brokers Lasair, ALeRCE, ANTARES, and Fink: ATLAS and its forced photometry server; the ASAS-SN Sky Patrol; and the ZTF Bright Transient Survey Explorer. We thank David Bishop for his compilation of supernovae. This project is part of a course in Astrophysical Techniques of the Master in Astrophysics of the Astrophysics Department of the University of La Laguna and Instituto de Astrofísica de Canarias (Tenerife, Canary Islands, Spain).