DRAFT
2025-01-28 14:35:32
Type: Object/s-Discovery/Classification
Bibcode: 2025TNSAN..41....1W
Shane Kast spectral classification of transients 2025-01-23
Authors: Jacob Wise (LJMU), K-Ryan Hinds (LJMU), Daniel Perley (LJMU), R. Michael Rich (UCLA)
Source Group: ZTF
Keywords: Spectroscopy, Transient, Supernova, Photometry
Abstract:
We report observations of 14 transients using the Shane Kast spectrograph at the Lick observatory on the nights of 2025-01-23 and 2025-01-24. New classifications were found for 10 objects, which includes 1 infant SN II, 2 SLSN-I, 6 SN Ia and 1 SN Ia-CSM.

We report the observation of 7 transients using the Kast Double Spectrograph on the 3.05 meter C. Donald Shane telescope at the Lick observatory. Observations were obtained between MJD 60699.10 and MJD 60700.51.

On the red side detector the 300/7500 grating was used, which has a dispersion of 2.55 Å/pixel. On the blue side the 600/4310 grism was used, which has a dispersion of 1.02 Å/pixel. A slit width of 1.5" was used for all observations. Part of 2024abpg/ZTF24abtejwy's observation sequence was mistakenly observed with a 0.5" slit width before we switched back to 1.5". Spectra were reduced using the UCSC Spectral Pipeline (Siebert et al. 2019). A spectral range of approximately 3470-10590 Å was obtained for the reduced spectra.

Of these 14 transients new classifications were found for 10 events, which includes 1 infant SN II, 2 SLSN-I, 6 SN Ia and 1 SN Ia-CSM. Our observations also support pre-existing classifications of 1 SN Ic, 1 SN Ia and 2 SN II. Classifications were performed by fitting observations to template spectra from previously classified transients using Next Generation Superfit (NGSF, Goldwasser et al. 2022) and manual inspection of line profiles.

Details of each observed transient are summarised in the "Related Objects" table. Our NGSF fits, plots of spectra which we classified manually, and spectral files for transients which we have not classified submitted a classification report for on TNS have been included in this Astronote.

Show current TNS values
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 2025adj [ATLAS25awc] 14:59:44.474 +51:27:46.98 SN II 0.011389 KUG 1458+516 0.011389 First discovered by the ATLAS survey on MJD 60699.61 and reported as a candidate supernova in AstroNote #2025-35. We observed a blue, mostly featureless spectrum consistent with it being a young SN II. Redshift of z = 0.011389 ± 0.000023 from SDSS DR13. 14:59:44.465 +51:27:47.06 SN II 0.011389
TNS 2024aezo [ATLAS24rwd] 13:24:17.079 +27:43:01.10 SLSN-I 0.4227 SSTSL2 J132417.09+274301.7 0.4227 ZTF internal name = ZTF24abwsvtj. Spectrum is well-fit to template spectra of the SLSN-I events iPTF13ajg, PTF12dam, PTF10aagc and PTF09cnd. Its lightcurve appears to be at a peak of g~19.1 in ZTF, which corresponds to a rest-frame peak absolute magnitude of M_u ~ -22.4 when applying a 2.5log10(1+z) K-correction. Reported as a hostless transient candidate by ELEPHANT in AstroNote #2025-6. We note that the host was imaged within the Subaru Deep Field. MMT/Hectospec and Keck/DEIMOS spectroscopic observations were taken by Chun Ly et at. 2016 between April 11 2008 and March 17 2015, in which they measure a redshift of z = 0.4227. 13:24:17.066 +27:43:01.14 SLSN-I 0.4227
TNS 2024xsk [ZTF24ablestl] 11:18:11.786 +26:03:23.40 SLSN-I 0.1686 RCS 04200003884 Spectrum is well-fit to template spectra of the SLSN-I events SN2011ke, LSQ14an, SN2015bn, SN2003jd and SN2010md. Redshift obtained using host galaxy H-alpha and [OIII] emission lines. 11:18:11.786 +26:03:23.40 SLSN-I 0.1686
TNS 2024abpg [ZTF24abtejwy] 00:14:17.798 +03:25:49.24 SN Ia-CSM 0.154 WISEA J001417.80+032551.3 Reported as a ZTF superluminous supernova candidate in AstroNote #2025-34. Spectrum is well-fit to template spectra of the SN Ia events SN2012Z, PTF10ops, SN2005hk and SN2002cx. Its lightcurve rises slowly in ZTF, with a ~40 observed day rise time to peak from first detection. These factors, combined with visible broad wings to its H-alpha profile, motivate us to classify this event as an SN Ia-CSM. Redshift obtained using H-alpha emission in observed spectrum. 00:14:17.798 +03:25:49.24 SN Ia-CSM 0.154
TNS 2025li [ZTF25aabegog] 12:45:55.093 +17:29:35.35 SN Ia 0.079202 WISEA J124555.09+172932.3 0.079202 Spectrum is well-fit to the template spectra of the SN Ia-norm events SN2011by, SN2011fe and SN2012ht. Redshift of z = 0.079202 ± 0.000008 from SDSS DR13 12:45:55.093 +17:29:35.35 SN Ia 0.079202
TNS 2024aglr [ZTF25aaaalin] 23:07:57.896 +25:03:40.97 SN Ia 0.0414 WISEA J230758.02+250343.3 Spectrum is well-fit to template spectra to the SN Ia-norm events SN2012cg, SN2012fr, SN2012ht and SN2015N. Redshift from host galaxy H-alpha emission. 23:07:57.908 +25:03:40.95 SN Ia 0.0414
TNS 2025kl [ZTF25aabowed] 01:11:52.757 +20:23:57.13 SN Ia 0.058 SDSS J011152.60+202358.9 Spectrum is well-fit to template spectra of the SN Ia-norm events SN2012cg, SN2011by, SN2011fe and SN2012fr. Redshift of z = 0.058 ± 0.003 found from NGSF template fits. 01:11:52.757 +20:23:57.13 SN Ia 0.058
TNS 2025jx [ZTF25aabovpf] 03:03:50.453 -00:12:13.25 SN Ia 0.027605 IC 0283 0.027605 Spectrum is well-fit to template spectra of the SN Ia-norm events SN2012ht, SN2011fe, SN2011by, SN1994D and SN2012cg. Redshift of z = 0.027605 ± 0.000012 from SDSS DR13. 03:03:50.453 -00:12:13.25 SN Ia 0.027605
TNS 2025hf [ZTF25aabmhdd] 12:29:16.826 +05:04:04.41 SN Ia 0.0718 SDSS J122916.88+050404.2 Spectrum is well-fit to template spectra of the SN Ia events SN2011by, SN2013dy, SN1999aa, SN2012cg and SN2011fe. Our classification is in agreement with the ePESSTO+ SN Ia classification from AstroNote #2025-39. Redshift obtained using host galaxy H-alpha emission. 12:29:16.826 +05:04:04.41 SN Ia 0.07
TNS 2025kd [ZTF25aabpoxz] 05:45:53.157 -25:53:17.05 SN Ia 0.0425 2MASS J05455310-2553158 Spectrum is well-fit to template spectra of the SN Ia events SN2015ac, SN2012ht, SN2012cg, SN2015N and PTF10ops. Redshift found using host-galaxy Na D absorption. 05:45:53.157 -25:53:17.05 SN Ia 0.0425
TNS 2025iv [GOTO25ft] 02:07:27.256 +19:11:36.88 SN Ic 0.0173 CGCG 461-046 ZTF internal name = ZTF25aabobjw. Spectrum is well-fit to SN Ic template spectra from the SN Ic events SN2007gr, SN1994I and SN2007ce. We also find good fits to the Ca-Ia SN2019ofm and the Ia 91bg-like SN2016ije. Our classification and redshift broadly agree with the SN Ic classification from ePESSTO+ in AstroNote #2025-30. 02:07:27.256 +19:11:36.88 SN Ic 0.0173
TNS 2025dc [ZTF25aaapkzn] 09:53:46.435 -08:18:09.09 SN II 0.047 WISEA J095346.29-081821.6 Spectrum displays a broad H-alpha P-Cygni profile characteristic of a SN II, with narrow host H-alpha emission at z = 0.047. Our classification and redshift agree with those found by ePESSTO+ in AstroNote #2025-36 09:53:46.435 -08:18:09.09 SN II 0.047
TNS 2025ei [ATLAS25agn] 11:44:47.403 +19:46:24.38 SN II 0.028247 NGC 3860B 0.028247 ZTF internal name = ZTF25aabskal. Spectrum shows H-alpha and H-beta P-cygni features characteristic of a SN II. Our classification agrees with with pre-existing TNS classification from SCAT, and ePESSTO+ in AstroNote #2025-8. Host redshift of 0.028247 ± 0.000008 from SDSS DR13. 11:44:47.404 +19:46:24.36 SN II 0.03
TNS 2025ky [ZTF22ablqzpz] 10:02:49.869 -05:51:12.65 SN Ia 0.0828 WISEA J100249.83-055112.0 Spectrum is low S/N due to high altitude clouds present during observation. We find tentative fits to template spectra from the SN Ia events SN2013dy, SN1999aa, PTF10ops and SN2009dc. We also find a tentative fit to the SN Ic-BL SN1998bw. Our fits are in broad agreement with the SN Ia classification found by ePESSTO+ in AstroNote #2025-39. Host redshift of z = 0.0828 ± 0.0004 from The 2dF Galaxy Redshift Survey: Final Data Release. 10:02:49.869 -05:51:12.65 SN Ia 0.0828
AstroNote Publication Timestamp Title Authors
2025-6 2025-01-07 20:40:15 Hostless candidates detected by ELEPHANT R. Durgesh (independent), P. Pessi (OKC), E. E. O. Ishida (CNRS), E. E. Hayes (KIC), L. Nakazono (USP), R. A. P. Oliveira (UW), A. Moitinho (CENTRA), A. Krone-Martins (UC), B. Moews (UE), R. S. de Souza (UH), R. Beck (independent), M. A. Kuhn (UH), K. Nowak (UH), and S. Vaughan (MU), for the COIN collaboration.
2025-8 2025-01-09 16:54:30 ePESSTO+ spectroscopic classification of optical transients F. Ragosta, I. Salmaso, S. Benetti, R. Carini, A. Melandri (INAF), C. Gutierrez (IEEC/ICE-CSIC), A. Kumar (RHUL/Warwick), K. Tsalapatas (Stockholm Univ.), E. Zimmerman (Weizmann), J. Anderson (ESO), T.-W. Chen (NCU), M. Gromadzki (Warsaw), C. Inserra (Cardiff), E. Kankare (Turku), T. Müller Bravo (Trinity), M. Nicholl (QUB), O. Yaron (Weizmann), D. Young (QUB), P. Pessi (Stockholm), J. Tonry, L. Denneau, H. Weiland, A. Lawrence, R. Siverd (IfA, University of Hawaii), N. Erasmus, W. Koorts (South African Astronomical Observatory), A. Jordan, V. Suc (UAI, Obstech), S. J. Smartt (Oxford/QUB), K. W. Smith, S. Srivastav, M. McCollum, T. Moore, J. Weston (QUB), L. Shingles (GSI/QUB), L. Rhodes (Oxford), J. Sommer (LMU/QUB), A. Rest (STScI), C. Stubbs (Harvard), X. Sheng, A. Aamer, C. R. Angus, D. Magill (QUB), P. Ramsden (QUB/Birmingham)
2025-30 2025-01-23 16:15:26 ePESSTO+ spectroscopic classification of optical transients H. Wichern, S. de Wet, G. Leloudas (DTU Space), S. Faris (TAU), T. Pessi (ESO), G. Pignata (UTA), M. Magee (Warwick), I. Arcavi (TAU), G. Dimitriadis (Lancaster), J. Sollerman (OKC), S. Benetti (INAF-OAPd), J. Anderson (ESO), T.-W. Chen (NCU), M. Gromadzki (Warsaw), C. Inserra (Cardiff), E. Kankare (Turku), T. Müller Bravo (Trinity), P. Pessi (Stockholm), O. Yaron (Weizmann), D. Young (QUB)
2025-34 2025-01-24 21:08:25 ZTF superluminous supernova candidates Ting-Wan Chen (NCU), Ragnhild Lunnan, Priscila J. Pessi, Anamaria Gkini (OKC), Steve Schulze (Northwestern), Jacob Wise, Daniel A. Perley (LJMU), Lin Yan (Caltech), Sean Brennan, Jesper Sollerman (OKC)
2025-35 2025-01-25 13:02:12 ATLAS25awc (AT2025adj): discovery of a candidate SN in KUG 1458+516 (48 Mpc) K. W. Smith (Oxford/QUB), D. R. Young, M. Nicholl, M. Fulton, M. McCollum, T. Moore, J. Weston, X. Sheng, A. Aamer, C. R. Angus, D. Magill (QUB), P. Ramsden (QUB/Birmingham), L. Shingles (GSI/QUB), S. J. Smartt (Oxford/QUB), S. Srivastav, J. Gillanders, H. Stevance, A. J. Cooper, F. Stoppa (Oxford), L. Rhodes (TSI/McGill), L. Denneau, J. Tonry, H. Weiland, R. Siverd (IfA, University of Hawaii), N. Erasmus, W. Koorts (South African Astronomical Observatory), A. Jordan, V. Suc (UAI, Obstech), A. Rest (STScI), T.-W. Chen (NCU), C. Stubbs (Harvard), J. Sommer (LMU), B. P. Schmidt (ANU)
2025-36 2025-01-26 13:10:45 ePESSTO+ spectroscopic classification of optical transients H. Wichern, S. de Wet, G. Leloudas (DTU Space), S. Faris (TAU), T. Pessi (ESO), G. Pignata (UTA), J. Sollerman (OKC), M. Gonzalez-Banuelos, C. Gutiérrez (IEEC/ICE-CSIC), J. Anderson (ESO), T.-W. Chen (NCU), M. Gromadzki (Warsaw), C. Inserra (Cardiff), E. Kankare (Turku), T. Müller Bravo (Trinity), P. Pessi (Stockholm), O. Yaron (Weizmann), D. Young (QUB), J. Tonry, L. Denneau, H. Weiland, A. Lawrence, R. Siverd (IfA, University of Hawaii), N. Erasmus, W. Koorts (South African Astronomical Observatory), A. Jordan, V. Suc (UAI, Obstech), S. J. Smartt (Oxford/QUB), K. W. Smith, S. Srivastav, M. McCollum, T. Moore, J. Weston (QUB), L. Shingles (GSI/QUB), L. Rhodes (Oxford), J. Sommer (LMU/QUB), A. Rest (STScI), C. Stubbs (Harvard), X. Sheng, A. Aamer, C. R. Angus, D. Magill (QUB), P. Ramsden (QUB/Birmingham)
File Comments
2025adj_0.png Plot of 2025adj/ATLAS25awc's spectrum
ZTF24abwsvtj_0.pdf NGSF fits of 2024aezo/ATLAS24rwd/ZTF24abwsvtj
ZTF24ablestl_0.pdf NGSF fits of 2024xsk/ZTF24ablestl
ZTF24abtejwy_0.pdf NGSF fits of 2024abpg/ZTF24abtejwy
ZTF25aabegog_0.pdf NGSF fits of 2025li/ZTF25aabegog
ZTF25aaaalin_0.pdf NGSF fits of 2024aglr/ZTF25aaaalin
ZTF25aabowed_0.pdf NGSF fits of 2025kl/ZTF25aabowed
ZTF25aabovpf_0.pdf NGSF fits of 2025jx/ZTF25aabovpf
ZTF25aabmhdd_0.pdf NGSF fits of 2025hf/ZTF25aabmhdd
ZTF25aabpoxz_0.pdf NGSF fits of 2025kd/ZTF25aabpoxz
ZTF25aabobjw_0.pdf NGSF fits of 2025iv/GOTO25ft/ZTF25aabobjw
ZTF25aabobjw_finalspec_0.txt 2025iv/GOTO25ft/ZTF25aabobjw spectral file
ZTF25aaapkzn_0.png Plot of 2025dc/ZTF25aaapkzn's spectrum
ZTF25aaapkzn_finalspec_0.txt 2025dc/ZTF25aaapkzn spectral file
ZTF25aabskal_0.png Plot of 2025ei/ATLAS25agn/ZTF25aabskal's spectrum
ZTF25aabskal_finalspec_0.txt 2025ei/ATLAS25agn/ZTF25aabskal spectral file
ZTF22ablqzpz_0.pdf NGSF fits of 2025ky/ZTF22ablqzpz
ZTF22ablqzpz_finalspec_0.txt 2025ky/ZTF22ablqzpz spectral file

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