We observed the transient AT2023zaw, discovered by Karambelkar et al., (AstroNote 2023-335) and Sollerman et al., (TNS TR No. 195300); see also Lee et al., (AstroNote 2023-338), Fulton et al., (AstroNote 2023-339) and Karambelkar et al., (AstroNote 2023-340), using the GMOS-N spectrograph at the Gemini-North observatory under the observing program ID GN-2023B-Q-125 (PI: M. Huber).
Our epoch of observation commenced approximately ~7 days post-explosion (estimated from the most recent ATLAS+ZTF non-detections). We obtained 4x600s exposures with the R400 grating, sampling a wavelength range of ~4200-9200 angstroms.
The reduced spectrum contains a number of broad P-Cygni features, from the He I 5678, 6678 and 7065 angstrom lines. We also note the presence of a strong P-Cygni feature due to the Ca II NIR triplet. We find reasonable matches to type Ib supernovae with SNID, a few days after peak.
The evolution of the lightcurve from ATLAS, ZTF and Kinder (AstroNotes 2023-335, 2023-338 and 2023-339) roughly resembles that of the fast transient AT2018kzr (McBrien et al., 2019, Gillanders et al., 2020), while the Gemini spectrum more closely resembles the ultra-stripped supernova SN2019wxt (Agudo et al., 2023).
Given all of the above, we classify AT2023zaw as a type Ib supernova, with an unusually fast-evolving lightcurve.
We thank the staff of the Gemini-North observatory for executing these observations.
| 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 | 2023zaw | 04:29:20.237 | +70:25:37.51 | SN Ib | UGC 03048 | 0.01015 | 04:29:20.235 | +70:25:37.52 | SN Ib |
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