TNS Classification Report No. 21875 [ 2025TNSCR3400....1R ]
Date Received (UTC): 2025-08-27 01:11:13 Sender: Filipp Romanov
Group: F. D. Romanov
Filipp Romanov (amateur astronomer, member of the AAVSO), Jacob Wise (LJMU), Christoffer Fremling (Caltech) report/s a classification of object: SN 2025umq
Type: SN IaRedshift: 0.159
Remarks: The spectrum of AT 2025umq (PSN J00481888+0759006) was obtained during 3400 seconds (PATAG proposal AZ22A01; PI: F. Romanov) on 2025-08-20, midtime 03:06:46 UT, remotely using the low resolution (approximately R = 350 = 18 Å) SPRAT (Piascik et al. 2014) spectrograph on the Liverpool Telescope with the red-optimised mode (grating option). The same image shows spectra of both the SN candidate and SDSS J004819.14+075856.8: the host galaxy spectrum shows H-alpha emission, and also sodium (Na D) absorption features, this allowed to narrow down the redshift to z = 0.159. Comparison (using the software package "Next Generation SuperFit" (NGSF): Goldwasser et al. 2022) of the spectrum of AT 2025umq to templates of previously classified transients at a redshift of z = 0.159, finding it to be consistent with a fading Type Ia supernova: the typical feature caused by high velocity iron is visible between approximately 5000 Å and 5500 Å; and silicon absorption feature is visible at approximately 7100 Å. ZTF light curve (presented online https://alerce.online/object/ZTF25abexekl , but the photometric data were not reported to the TNS) shows the first g-band detection on 2025-07-25 and the peak magnitude of about +20 near August 10, 2025. Calculation with K-correction shows the absolute magnitude of about -19.6, this also corresponds to a Type Ia supernova. Based on the above, we classify AT 2025umq as Ia supernova in the galaxy SDSS J004819.14+075856.8.
The following Classification spectrum was provided:
Obsdate: 2025-08-20 03:06:46
Instrument: SPRAT
Telescope: Liverpool Telescope
Details of the object and its spectra can be viewed here: https://www.wis-tns.org/object/2025umq
Date Received (UTC): 2025-08-27 01:11:13 Sender: Filipp Romanov
Group: F. D. Romanov
Filipp Romanov (amateur astronomer, member of the AAVSO), Jacob Wise (LJMU), Christoffer Fremling (Caltech) report/s a classification of object: SN 2025umq
Type: SN IaRedshift: 0.159
Remarks: The spectrum of AT 2025umq (PSN J00481888+0759006) was obtained during 3400 seconds (PATAG proposal AZ22A01; PI: F. Romanov) on 2025-08-20, midtime 03:06:46 UT, remotely using the low resolution (approximately R = 350 = 18 Å) SPRAT (Piascik et al. 2014) spectrograph on the Liverpool Telescope with the red-optimised mode (grating option). The same image shows spectra of both the SN candidate and SDSS J004819.14+075856.8: the host galaxy spectrum shows H-alpha emission, and also sodium (Na D) absorption features, this allowed to narrow down the redshift to z = 0.159. Comparison (using the software package "Next Generation SuperFit" (NGSF): Goldwasser et al. 2022) of the spectrum of AT 2025umq to templates of previously classified transients at a redshift of z = 0.159, finding it to be consistent with a fading Type Ia supernova: the typical feature caused by high velocity iron is visible between approximately 5000 Å and 5500 Å; and silicon absorption feature is visible at approximately 7100 Å. ZTF light curve (presented online https://alerce.online/object/ZTF25abexekl , but the photometric data were not reported to the TNS) shows the first g-band detection on 2025-07-25 and the peak magnitude of about +20 near August 10, 2025. Calculation with K-correction shows the absolute magnitude of about -19.6, this also corresponds to a Type Ia supernova. Based on the above, we classify AT 2025umq as Ia supernova in the galaxy SDSS J004819.14+075856.8.
The following Classification spectrum was provided:
Obsdate: 2025-08-20 03:06:46
Instrument: SPRAT
Telescope: Liverpool Telescope
Details of the object and its spectra can be viewed here: https://www.wis-tns.org/object/2025umq