DRAFT
2025-01-11 06:04:31
Type: Object/s-Discovery/Classification
Bibcode: 2025TNSAN..15....1C
adH0cc spectroscopic classification of SN 2025gc
Source Group: adH0cc
Abstract:
We have obtained an optical spectrum of SN 2025gc, which shows it to be a Type Ic supernova exhibiting SN 1998bw-like features, about a month after maximum light. The supernova occurred in the same galaxy as the Type Ia SN 2009aa.
The adH0cc programme for an "accurate determination of H0 with core-collapse supernovae" reports the classification of the optical transient SN 2025gc. The target was supplied by the Pan-STARRS Survey for Transients(Chambers et al. 2016, 2016arXiv161205560C). The observations were performed on the night of 2025-01-08 with the ESO Very Large Telescope UT1, equipped with the FORS2 spectrograph and grism 300V, covering a wavelength range from 3400 to 9600 Å at a resolution of 10 Å.
| Catalog | Name | Reported RA | Reported DEC | Reported Obj-Type | Reported Redshift | Host Name | Host Redshift | Source | Phase | Remarks | TNS RA | TNS DEC | TNS Obj-Type | TNS Redshift |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| TNS | 2025gc [PS25bb] | 11:23:40.021 | -22:16:09.17 | SN Ic | 0.02731 | ESO570-G020 | 0.02731 | Pan-STARRS | 40 d | Spectrum shows broad Ca emission and is matched well by the spectra of 1997ef 35 to 45 days after maximum. We note that this phase is in disagreement with the Pan-STARRS non-detections which set the current maximal age of the SN to 16 days. The supernova occured in the same galaxy as SN 2009aa, a Type Ia supernova. We adopted the host galaxy redshift for the SN. | 11:23:40.021 | -22:16:09.17 | SN Ic | 0.02731 |
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