RA/DEC (2000)
15:38:58.129 -22:40:11.38
234.742202237 -22.6698280264
Type
SN II
Redshift
0.0198
Related AstroNotes: 2025-103, 2025-141
Reporting Group
ATLAS
Discovering Data Source
ATLAS
Discovery Date
2025-04-01 04:38:17.664
TNS AT
Y
Public
Y
Discovery Mag
18.276
Filter
cyan-ATLAS
Reporter/s
J. Tonry, L. Denneau, H. Weiland, R. Siverd (IfA, University of Hawaii), N. Erasmus, W. Koorts (South African Astronomical Observatory), A. Jordan, V. Suc (UAI, Obstech), S. J. Smartt, K. W. Smith (Oxford/QUB), D. R. Young, M. Nicholl, M. Fulton, M. McCollum, T. Moore, J. Weston, X. Sheng, C. R. Angus, A. Wilson, A. Aamer, D. Magill (QUB), P. Ramsden (Birmingham/QUB), L. Shingles (GSI/QUB), S. Srivastav, J. H. Gillanders, H. Stevance, A. J. Cooper, F. Stoppa, J. Tweddle (Oxford), L. Rhodes (TSI/McGill), A. Rest (STScI), T.-W. Chen (NCU), C. Stubbs (Harvard), J. S. Sommer (LMU), B. P. Schmidt (ANU)

Spectra

 SN_2025gjc - 2025-05-08 01:27:24 NOT / ALFOSC (None)z=
 SN_2025gjc - 2025-04-01 21:57:30 Lesedi / Mookodi (BlackGEM)z=
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   Binning factor: (rounded to nearest integer >1)
Mouse hovers at WL: 0 (rest),0 (observed)

Light curves

 GOTO-S_GOTO-4_L
 ATLAS-CHL_ATLAS-04_cyan
 P48_ZTF-Cam_r
 P48_ZTF-Cam_g
 PS1_GPC1_w
   
Pointer position (MJD, Mag, Abs.Mag): (0.00, 0.00, 0.00)
Spectra
ID Obs-date (UT) Tel / Inst Exp-Time Observer/s Reducer/s Group Spectrum ascii file Spectrum fits file Spec. Type Assoc. Groups End prop. period Remarks
21000 2025-05-08 01:27:24 NOT / ALFOSC Obs II course SU None tns_2025gjc_2460803.56069_NOT_ALFOSC_None.ascii Object
20685 2025-04-01 21:57:30 Lesedi / Mookodi 2400 N. Erasmus, S. Potter, C. van Gend, H. Worters, S. Chandra, D. Cunnama, M. Hlakola, P. Rabe, R. Julie (all SAAO) Simon de Wet BlackGEM tns_2025gjc_2025-04-01_21-57-30_Lesedi_Mookodi_BlackGEM.txt Object The spectrum was taken with the SAAO's 1-m Lesedi telescope with the Mookodi low-resolution spectrograph and imager [1] as part of the “IO” rapid follow-up program [2]. The spectrum was taken with the widest (4") slit width which resulted in a spectral resolution of R ~ 200 at 6000 Angstrom. [1] https://doi.org/10.1117/1.JATIS.10.2.025005 [2] https://doi.org/10.1117/12.3015250
Light Curves
Filter Tel / Inst Obs-date range JD Range Photometry
L-GOTO GOTO-S_GOTO-4 2025-03-15 14:26:23 - 2025-04-02 13:19:32 2460750.101658 - 2460768.055233 2
Photometry
ID Obs-date JD Mag. / Flux Err Lim. Mag./Flux Units Filter Tel / Inst Exp-time Observer/s Remarks
480674 2025-04-02 13:19:32 2460768.055233 17.98 0.04 ABMag L-GOTO GOTO-S_GOTO-4 180
480673 2025-03-15 14:26:23 2460750.101658 18.6 ABMag L-GOTO GOTO-S_GOTO-4 180 [Last non detection]
cyan-ATLAS ATLAS-CHL_ATLAS-04 2025-03-31 06:15:49 - 2025-04-01 04:38:18 2460765.76098 - 2460766.69326 2
Photometry
ID Obs-date JD Mag. / Flux Err Lim. Mag./Flux Units Filter Tel / Inst Exp-time Observer/s Remarks
480005 2025-04-01 04:38:18 2460766.69326 18.276 0.103 19.2 ABMag cyan-ATLAS ATLAS-CHL_ATLAS-04 30 Robot
480004 2025-03-31 06:15:49 2460765.76098 19 ABMag cyan-ATLAS ATLAS-CHL_ATLAS-04 30 Robot [Last non detection]
r-ZTF P48_ZTF-Cam 2025-04-07 10:24:11 - 2025-04-07 10:24:11 2460772.9334606 - 2460772.9334606 1
Photometry
ID Obs-date JD Mag. / Flux Err Lim. Mag./Flux Units Filter Tel / Inst Exp-time Observer/s Remarks
481193 2025-04-07 10:24:11 2460772.9334606 17.5826 0.0514471 ABMag r-ZTF P48_ZTF-Cam
g-ZTF P48_ZTF-Cam 2025-03-30 11:48:42 - 2025-04-07 10:10:49 2460764.9921528 - 2460772.9241782 2
Photometry
ID Obs-date JD Mag. / Flux Err Lim. Mag./Flux Units Filter Tel / Inst Exp-time Observer/s Remarks
481192 2025-04-07 10:10:49 2460772.9241782 17.6888 0.055171 ABMag g-ZTF P48_ZTF-Cam
481191 2025-03-30 11:48:42 2460764.9921528 19.485 ABMag g-ZTF P48_ZTF-Cam [Last non detection]
w-P1 PS1_GPC1 2025-03-31 13:29:25 - 2025-03-31 13:29:25 2460766.06209 - 2460766.06209 1
Photometry
ID Obs-date JD Mag. / Flux Err Lim. Mag./Flux Units Filter Tel / Inst Exp-time Observer/s Remarks
480188 2025-03-31 13:29:25 2460766.06209 18.67 0.02 22 ABMag w-P1 PS1_GPC1 45 Robot
AT Reports
ID Time received (UT) Sender Reporter/s Reporting group Disc. Data Source RA DEC Discovery date (UT) Discovery Mag. Filter Related files AT Type Host name Internal name Assoc. Groups End prop. period Remarks ADS Bibcode Unreal Auto classification
251141 2025-04-07 10:54:56 Fritz K-Ryan Hinds (LJMU),Christoffer Fremling (Caltech),Daniel Perley (LJMU) et al. ZTF ZTF 15:38:58.127 -22:40:11.48 2025-04-07 10:10:48.996 17.6888 g-ZTF PSN ZTF25aalvbwm ZTF N
250867 2025-04-04 08:50:57 GOTO_bot B. Godson,D. O'Neill,K. Ackley et al. GOTO GOTO 15:38:58.122 -22:40:11.46 2025-04-02 13:19:31.872 17.98 L-GOTO Other GOTO25bjo GOTO N
250545 2025-04-02 10:40:18 PS1_Bot1 K. C. Chambers,T. de Boer,J. Fairlamb et al. Pan-STARRS Pan-STARRS 15:38:58.129 -22:40:11.38 2025-03-31 13:29:24.576 18.67 w-P1 PSN PS25ayx Pan-STARRS N
250452 2025-04-01 07:47:52 ATLAS_Bot1 J. Tonry,L. Denneau,H. Weiland et al. ATLAS ATLAS 15:38:58.106 -22:40:11.60 2025-04-01 04:38:17.664 18.276 cyan-ATLAS PSN ATLAS25dkq ATLAS 2025TNSTR1224....1T N
Classification Reports
ID Time received (UT) Sender Classifier/s Group Classification Redshift Spectra Related files Assoc. Groups End prop. period Remarks ADS Bibcode
21000 2025-05-08 14:52:00 Priscila Pessi Joanna Pajak, Logan Peschieras, Warsame Mohamed Ali, Pak Hei Chan, Nikolei Höglinger, Evgenia Lamprou, Rikard Lesley, Håkan Lundberg, Nikolas Valsamidis, Terese Thidemann Hansen, Anjasha Gangopadhyay, Jesper Sollerman, Konstantinos Tsalapatas, Priscila Pessi (SU,OKC) None SN II 0.0198 1 This SN was previously classified as IIn. We do not see narrow lines in the new spectrum, except maybe for host line contamination. Instead, the P-Cygni profile suggests a Type II classification. Reported on AstroNote 2025-141. 2025TNSCR1718....1P
Spectra
ID Obs-date (UT) Tel / Inst Exp-Time Observer/s Reducer/s Group Spectrum ascii file Spectrum fits file Spec. Type Assoc. Groups End prop. period Remarks
21000 2025-05-08 01:27:24 NOT / ALFOSC Obs II course SU None tns_2025gjc_2460803.56069_NOT_ALFOSC_None.ascii Object
20685 2025-04-03 09:01:38 Simon de Wet Simon de Wet BlackGEM SN IIn 0.0198 1 BlackGEM We tentatively classify AT2025gjc as a Type IIn supernova based on the presence of Balmer emission lines. The redshift is derived from Halpha line. 2025TNSCR1258....1W
Spectra
ID Obs-date (UT) Tel / Inst Exp-Time Observer/s Reducer/s Group Spectrum ascii file Spectrum fits file Spec. Type Assoc. Groups End prop. period Remarks
20685 2025-04-01 21:57:30 Lesedi / Mookodi 2400 N. Erasmus, S. Potter, C. van Gend, H. Worters, S. Chandra, D. Cunnama, M. Hlakola, P. Rabe, R. Julie (all SAAO) Simon de Wet BlackGEM tns_2025gjc_2025-04-01_21-57-30_Lesedi_Mookodi_BlackGEM.txt Object The spectrum was taken with the SAAO's 1-m Lesedi telescope with the Mookodi low-resolution spectrograph and imager [1] as part of the “IO” rapid follow-up program [2]. The spectrum was taken with the widest (4") slit width which resulted in a spectral resolution of R ~ 200 at 6000 Angstrom. [1] https://doi.org/10.1117/1.JATIS.10.2.025005 [2] https://doi.org/10.1117/12.3015250

Comments

TNS
System

Object coordinates updated

Object coordinates updated according to AT-report 250545 of Group Pan-STARRS
Previous RA, DEC: 15:38:58.106, -22:40:11.60 (234.742109091, -22.6698881818)
Updated RA, DEC: 15:38:58.129, -22:40:11.38 (234.742202237, -22.6698280264)