The Zwicky Transient Facility (ZTF; Bellm et al. 2019; Graham et al. 2019) Superluminous Supernova Science Program (Lunnan et al. 2020; Yan et al. 2020; Chen et al. 2023a,b; Pessi et al. 2025) reports 6 candidate SLSNe, following the methodology outlined by Perley et al. (in prep.) We selected transients that have long rise time (>20 days) and/or faint host galaxies.
We summarise properties of the candidates in the Related Objects Table. These include coordinates, current magnitudes, approximate rise times, photometric redshifts of potential host galaxies (taken from the SDSS DR14) and special remarks.
Spectroscopic classifications and additional follow-up observations of these transients are encouraged.
This report is based on observations obtained with the Samuel Oschin Telescope 48-inch and the 60-inch Telescope at the Palomar Observatory as part of the Zwicky Transient Facility project. ZTF is supported by the National Science Foundation under Award #2407588 and a partnership including Caltech, USA; Caltech/IPAC, USA; University of Maryland, USA; University of California, Berkeley, USA; University of Wisconsin at Milwaukee, USA; Cornell University, USA; Drexel University, USA; University of North Carolina at Chapel Hill, USA; Institute of Science and Technology, Austria; National Central University, Taiwan, and OKC, University of Stockholm, Sweden. Operations are conducted by Caltech's Optical Observatory (COO), Caltech/IPAC, and the University of Washington at Seattle, USA.
| 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 | 2025lsl [ZTF25aaoxgmt] | 16:29:25.326 | +37:50:03.05 | Slowly rising over 50 days, currently r~19.8 mag. Hostless to the depth of PS1 and LS. Initially reported by YSE as PS25cvl. | 16:29:25.332 | +37:50:03.06 | ||||||
| TNS | 2025izy [ZTF25aanxtou] | 19:49:06.908 | +78:51:20.32 | Now just past peak following a 60-day rise, and at r~19.0 mag. No photo-z available; faint host barely visible in PS1. Also reported as a SLSN candidate by NEEDLE (AstroNote 2025-161) and hostless candidate by ELEPHANT (AstroNote 2025-143). | 19:49:06.908 | +78:51:20.32 | SLSN-I | 0.1734 | ||||
| TNS | 2025evp [ZTF25aaispqu] | 06:05:45.985 | +48:29:48.79 | Rising for 90 days in ZTF data, currently r~17.9 mag, field is setting. Host galaxy has a PS1_STRM photo-z of 0.17. | 06:05:45.985 | +48:29:48.79 | ||||||
| TNS | 2025kkb [ZTF25aaofttb] | 13:11:37.507 | +10:19:59.24 | Slowly rising over 60 days, currently g~19.5 mag with g-r~0. No host galaxy visible to the depth of PS1 or Legacy Survey. | 13:11:37.507 | +10:19:59.24 | SLSN-I | 0.58 | ||||
| TNS | 2025inr [ZTF25aaomnws] | 15:23:10.920 | +76:01:00.84 | SN | 0.176 | 30-day rise followed by plateau; currently r~18.9 mag. An SEDM spectrum gives the redshift as 0.176 based on host Halpha and [OIII] lines, implying a peak absolute magnitude M_g = -20.9 mag, but there are no broad features in the spectrum to determine subtype. Also reported as a SLSN candidate by NEEDLE (AstroNote 2025-175). First discovered by ATLAS as ATLAS25ekj. | 15:23:10.920 | +76:01:00.84 | SN | 0.176 | ||
| TNS | 2025gyv [ZTF25aalsbpm] | 10:38:24.082 | +68:02:25.02 | Currently just past peak following a 60-day rise, with r~18.4 mag. Hostless to the depth of PS1 and LS. Also reported as a SLSN candidate by NEEDLE (AstroNote 2025-132) and as a hostless transient by ELEPHANT (AstroNote 2025-136). | 10:38:24.082 | +68:02:25.02 |


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