TNS Classification Report No. 21683 [ 2025TNSCR3031....1M ]
Date Received (UTC): 2025-08-01 18:39:28 Sender: Moses Mlangeni
Group: BlackGEM
Moses Mlangeni (UCT/SAAO), Orapoleng Mogawana (UCT/SAAO), Francois Campher (UCT/SAAO), Paul Groot (Radboud/UCT/SAAO), Fiorenzo Stoppa (Oxford), Erez Zimmerman (Weizmann), Hugo Tranin (Barcelona) report/s a classification of object: SN 2025rtk
Type: SN IaRedshift: 0.0206
Remarks: We obtained an optical spectrum of AT2025rtk on 2025-08-01 01:48:20.748 UTC using the Lesedi 1.0-m telescope at the South African Astronomical Observatory (SAAO) equipped with the Mookodi spectrograph. The data were reduced using standard procedures, and the resulting spectrum was analysed with both the NGSF and SNID classification tools. Both tools consistently classify the transient as a normal Type Ia supernova (SN Ia-norm). The spectrum shows the characteristic broad Si II λ6355 absorption feature near 6150 Å (rest frame) consistent with a normal SN Ia at an early phase. We adopt the host galaxy redshift of z = 0.020631 (from NED) for this classification. Our measured redshift from the SN spectrum (z ≈ 0.0225) is consistent within expected uncertainties due to SN ejecta velocities.
The following Classification spectrum was provided:
Obsdate: 2025-08-01 01:48:21
Instrument: Mookodi
Telescope: Lesedi 1m
Details of the object and its spectra can be viewed here: https://www.wis-tns.org/object/2025rtk
Date Received (UTC): 2025-08-01 18:39:28 Sender: Moses Mlangeni
Group: BlackGEM
Moses Mlangeni (UCT/SAAO), Orapoleng Mogawana (UCT/SAAO), Francois Campher (UCT/SAAO), Paul Groot (Radboud/UCT/SAAO), Fiorenzo Stoppa (Oxford), Erez Zimmerman (Weizmann), Hugo Tranin (Barcelona) report/s a classification of object: SN 2025rtk
Type: SN IaRedshift: 0.0206
Remarks: We obtained an optical spectrum of AT2025rtk on 2025-08-01 01:48:20.748 UTC using the Lesedi 1.0-m telescope at the South African Astronomical Observatory (SAAO) equipped with the Mookodi spectrograph. The data were reduced using standard procedures, and the resulting spectrum was analysed with both the NGSF and SNID classification tools. Both tools consistently classify the transient as a normal Type Ia supernova (SN Ia-norm). The spectrum shows the characteristic broad Si II λ6355 absorption feature near 6150 Å (rest frame) consistent with a normal SN Ia at an early phase. We adopt the host galaxy redshift of z = 0.020631 (from NED) for this classification. Our measured redshift from the SN spectrum (z ≈ 0.0225) is consistent within expected uncertainties due to SN ejecta velocities.
The following Classification spectrum was provided:
Obsdate: 2025-08-01 01:48:21
Instrument: Mookodi
Telescope: Lesedi 1m
Details of the object and its spectra can be viewed here: https://www.wis-tns.org/object/2025rtk