DRAFT
2025-06-06 21:48:01
Type: Object/s-Discovery/Classification
NOT spectroscopic classifications of optical transients
Authors: Gerard García Moreno, Mathias Gort, Nadejda Blagorodnova (ICCUB), John A. Paice (Durham), Marco A. Gómez-Muñoz, Hugo Tranin, Grace Katusiime (ICCUB)
Source Group: BlackGEM
Abstract:
We report the spectroscopic classification with NOT/ALFOSC of 9 optical transients. 3 CVs, 1 SN Ia, 1 SN Ic-BL, 2 SN II, 1 featureless continuum, and 1 Microlensing event.

We report the spectroscopic classification of 9 objects, several of which were co-discovered by the BlackGEM telescope array (Groot et al. 2024). These data are part of the BlackGEM pilot verification program “Discovering the hidden gems in the transient sky” (PI: Blagorodnova).

The observations were performed on the night of 2025 June 1st UT with the NOT telescope, equipped with the ALFOSC spectrograph and low-resolution grism #4 and slits of 1.0 and 1.3 arcsec, covering a wavelength range from 3500-9600 Å at a resolution of 16.2 Å and 21 Å respectively. 

Classifications were done using the Python package Next Generation SuperFit (NGSF; Astronote 2022-191).

Based on observations made with the Nordic Optical Telescope, owned in collaboration by the University of Turku and Aarhus University, and operated jointly by Aarhus University, the University of Turku and the University of Oslo, representing Denmark, Finland and Norway, the University of Iceland and Stockholm University at the Observatorio del Roque de los Muchachos, La Palma, Spain, of the Instituto de Astrofisica de Canarias.

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 2020nkz [Gaia20cxx] 16:04:10.560 +14:56:18.35 CV 0 16:04:10.560 +14:56:18.35 CV
TNS 2025iww [ZTF25aaoqyej] 14:56:15.269 -05:54:37.35 SN Ia 0.1 14:56:15.269 -05:54:37.35 SN Ia 0.1
TNS 2025kha [ZTF25aaptvbh] 14:54:53.363 +05:30:04.21 SN II 0.06 14:54:53.363 +05:30:04.21 SN II 0.06
TNS 2025koz [ZTF25aaqocue] 16:09:17.649 +09:40:46.49 SN Ic-BL 0.1 16:09:17.649 +09:40:46.49 SN Ic-BL 0.1
TNS 2025lji [KATS25K010] 22:50:29.060 +65:19:23.30 CV 0 Dwarf nova candidate 22:50:29.060 +65:19:23.30
TNS 2025ljk [KATS25K012] 18:24:05.340 -22:33:35.20 Other 0 Microlensing candidate 18:24:05.340 -22:33:35.20
TNS 2025ljt [ZTF25aardghz] 16:53:20.693 -08:25:32.30 CV 0 16:53:20.693 -08:25:32.30 CV
TNS 2025lsf [GOTO25dad] 14:27:59.673 +05:38:49.74 SN II 0.05 14:27:59.667 +05:38:49.76 SN II 0.05
TNS 2025lyx [ZTF25aarzkbz] 20:59:34.251 -17:44:31.49 Other SDSS J205934.25-174431.6 Blue, featureless continuum 20:59:34.251 -17:44:31.49

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