Each SN is classified by running the spectrum closest to the V-band maximum and the available earliest spectrum through SNID (see Section 4 for details) with the most updated SESNe template library (Modjaz et al. 2014; Liu et al. 2016, 2017; Williamson et al. 2019, 2023).

Redshift values are obtained from TNS, except for SN 2022nyo, for which the redshift was assumed to be the redshift of its host galaxy available on NASA/IPAC Extragalactic Database (NED; Helou et al. 1991).

The total number of photospheric spectra for the corresponding SN included in this work.

For these 2 SNe, the LCO V-band light curves do not capture the rise to the peak. Therefore, the i-band light curve is used to calculate the date of the peak and is later converted to the date of the peak in the V-band using Table 10 of Bianco et al. (2014), assuming these SN lightcurves have the same behavior of the SESNe in Bianco et al. (2014). Conversion of the date of the peak in the i band to the date of the peak in the V band adds a systematic uncertainty of ∼1.5 days. We note that the additional systematic uncertainty of ∼1.5 days from converting from i-band to V-band is not listed in the entries above. Additionally, using the conversion relationship between the date of maximum in the V-band and i-band from Rodríguez et al. (2023) (see Section 3), we obtain t_Vmax = 59442.06 ± 1.63 and 59312.13 ± 1.62 for SNe 2021ukt and 2021hen respectively.

The earliest spectrum of SN 2022nyo, obtained on UT 2022-07-03 01:55:28 (with t_Vmax = −13.8 days), shows a prominent hydrogen-like feature around 6200 Å. This characteristic signature of a hydrogen line is further validated by the SNID results, which identify the best match with SN 2008cw (type IIb). However, subsequent spectra acquired on UT 2022-07-12 18:29:14 (with t_Vmax = −4.1 days) display spectral characteristics consistent with SNe Ib (see Section 4.2 for further details).

SN 2021ukt is a peculiar SN Ib with IIn-like features (see the Section 4.3 about this SN): at early times, the TNS spectrum showed only Hα and no He absorption lines, thus the SN IIn classification above, but over times the multiple He absorption lines arise clearly, thus the SN Ib classification, while the narrow Hα line persisted at weaker, but varying, levels of strength.

SNID initially classifies SN 2019odp as broad-line type Ic (Ic-bl) based on its spectra taken before the V-band maximum light (t_Vmax < 0), but later classifies it as type Ib based on the spectra taken after the V-band maximum light (t_Vmax > 0). See Section 4.7 for more information.