Spectroscopic Classification of Astrophysical Transients with the Lick Shane Telescope

ATel #17161; R. Kaur, K. W. Davis, R. J. Foley (UCSC)
on 24 Apr 2025; 21:07 UT
Distributed as an Instant Email Notice Supernovae
Credential Certification: Ryan Foley (foley@ucsc.edu)

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We report the classifications of astrophysical transients from spectroscopic observations with the Kast spectrograph on the Shane telescope obtained on 2025 April 09 UT. The targets were supplied by GOTO and ATLAS. Targets were identified using the target management platform YSE-PZ (Coulter et al., 2023, PASP, 135, 4501). The classifications were performed with SNID (Blondin & Tonry, 2007, ApJ, 666, 1024).

 
Name         | IAU Name   | RA (J2000)   | Dec (J2000)  |   z   | Type | Phase | Notes
 
GOTO25amj    | AT2025cav  | 09:12:08.043 | +41:19:03.31 | 0.092 |  Ic  | peak  | (1) 
ATLAS25cxa	 | SN2025few  | 12:33:20.814 | +27:06:34.44 | 0.025 |  Ib  | peak  | (2) 
 

Notes: When the redshift is given to 2 decimal places, it is derived from the SN spectrum. Otherwise, the redshift is determined from the host galaxy. (1) We note that at z = 0.092, the SN has a peak r-band absolute magnitude of ~-19 mag, which is high for the SN Ic luminosity distribution (Drout et al., 2011, ApJ, 741, 97). Although SNID also finds acceptable matches to SNe Ia-91T, the light curve shows a long photometric rise of nearly 2 months. Thus, we rule out (relatively normal) SN Ia classifications. (2) SN2025few was previously classified as "SN" by Desai (2025, TNSCR 1141).