RA/DEC (2000)
04:41:28.861 -02:51:55.61
70.370254 -2.865447
Type
SN IIP
Redshift
Discovery ReportClassification Report
Related AstroNotes: 2025-216, 2025-266
Reporting Group
ASAS-SN
Discovering Data Source
ASAS-SN
Discovery Date
2025-06-29 10:19:12.000
TNS AT
Y
Public
Y
Host Name
NGC 1637
Host Redshift
0.002392
Discovery Mag
13.3
Filter
g-Sloan
Reporter/s
K. Z. Stanek, for the ASAS-SN team
NEDSIMBADDECaLSPanSTARRS-1SkyMapperVizieRWISEDSSADS

Spectra

 ▌SN_2025pht - 2025-07-03 10:18:06 SOAR / Goodman (None)z=
▌Show H at z=vexp= km/s
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▌Show Mg at z=vexp= km/s
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▌Show Ca II at z=vexp= km/s
▌Show [Ca II] at z=vexp= km/s
▌Show Fe II at z=vexp= km/s
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▌Show Tellurics 
▌Show Galaxy lines at z=
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▌Show WR-WC/O at z=vexp= km/s
   Binning factor: (rounded to nearest integer >1)
Mouse hovers at WL: 0 (rest),

Light curves

 ▌GOTO-N_GOTO-2_L
 ▌ATLAS-CHL_ATLAS-04_cyan
 ▌ATLAS-STH_ATLAS-03_orange
 ▌GOTO-N_GOTO-1_L
 ▌BG3_BlackGEM-Cam3_BG-q
 ▌P48_ZTF-Cam_g
 ▌ASASSN-5_Payne-Gaposchkin_g
 ▌ASASSN-2_Cassius_g
   
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
21466 2025-07-03 10:18:06 SOAR / Goodman Jay Strader, Ryan Urquhart None tns_2025pht_2025-07-03_10-18-06_SOAR_Goodman_None.dat Object
Light Curves
Filter Tel / Inst Obs-date range JD Range Photometry
L-GOTO GOTO-N_GOTO-2 2025-08-15 05:36:58 - 2025-08-15 05:36:58 2460902.734011 - 2460902.734011 1
Photometry
ID Obs-date JD Mag. / Flux Err Lim. Mag./Flux Units Filter Tel / Inst Exp-time Observer/s Remarks
527039 2025-08-15 05:36:58 2460902.734011 14.51 0.03 ABMag L-GOTO GOTO-N_GOTO-2 180
cyan-ATLAS ATLAS-CHL_ATLAS-04 2025-07-23 10:23:31 - 2025-07-23 10:23:31 2460879.933 - 2460879.933 1
Photometry
ID Obs-date JD Mag. / Flux Err Lim. Mag./Flux Units Filter Tel / Inst Exp-time Observer/s Remarks
554411 2025-07-23 10:23:31 2460879.933 19.13 ABMag cyan-ATLAS ATLAS-CHL_ATLAS-04 30 Robot [Last non detection]
orange-ATLAS ATLAS-STH_ATLAS-03 2025-07-29 03:54:27 - 2025-07-29 03:54:27 2460885.66281 - 2460885.66281 1
Photometry
ID Obs-date JD Mag. / Flux Err Lim. Mag./Flux Units Filter Tel / Inst Exp-time Observer/s Remarks
554412 2025-07-29 03:54:27 2460885.66281 13.615 0.006 18.88 ABMag orange-ATLAS ATLAS-STH_ATLAS-03 30 Robot
L-GOTO GOTO-N_GOTO-1 2025-02-24 21:54:22 - 2025-02-24 21:54:22 2460731.412763 - 2460731.412763 1
Photometry
ID Obs-date JD Mag. / Flux Err Lim. Mag./Flux Units Filter Tel / Inst Exp-time Observer/s Remarks
527038 2025-02-24 21:54:22 2460731.412763 19.5 ABMag L-GOTO GOTO-N_GOTO-1 180 [Last non detection]
BG-q-BlackGem BG3_BlackGEM-Cam3 2025-02-04 01:21:01 - 2025-07-22 10:22:51 2460710.5562616 - 2460878.9325347 2
Photometry
ID Obs-date JD Mag. / Flux Err Lim. Mag./Flux Units Filter Tel / Inst Exp-time Observer/s Remarks
507630 2025-07-22 10:22:51 2460878.9325347 13.98 0.02 19.99 ABMag BG-q-BlackGem BG3_BlackGEM-Cam3 60 robotic
507629 2025-02-04 01:21:01 2460710.5562616 20.51 ABMag BG-q-BlackGem BG3_BlackGEM-Cam3 60 robotic [Last non detection]
g-ZTF P48_ZTF-Cam 2025-08-17 11:21:27 - 2025-08-25 11:53:17 2460904.9732292 - 2460912.9953356 2
Photometry
ID Obs-date JD Mag. / Flux Err Lim. Mag./Flux Units Filter Tel / Inst Exp-time Observer/s Remarks
512204 2025-08-25 11:53:17 2460912.9953356 15.7952 0.0274795 ABMag g-ZTF P48_ZTF-Cam
512203 2025-08-17 11:21:27 2460904.9732292 15.4333 0.0322085 ABMag g-ZTF P48_ZTF-Cam
g-Sloan ASASSN-5_Payne-Gaposchkin 2025-04-06 17:16:48 - 2025-04-06 17:16:48 2460772.22 - 2460772.22 1
Photometry
ID Obs-date JD Mag. / Flux Err Lim. Mag./Flux Units Filter Tel / Inst Exp-time Observer/s Remarks
499240 2025-04-06 17:16:48 2460772.22 17 ABMag g-Sloan ASASSN-5_Payne-Gaposchkin [Last non detection]
g-Sloan ASASSN-2_Cassius 2025-06-29 10:19:12 - 2025-06-29 10:19:12 2460855.93 - 2460855.93 1
Photometry
ID Obs-date JD Mag. / Flux Err Lim. Mag./Flux Units Filter Tel / Inst Exp-time Observer/s Remarks
499241 2025-06-29 10:19:12 2460855.93 13.3 ABMag g-Sloan ASASSN-2_Cassius
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
289231 2026-01-28 16:30:08 ATLAS_Bot1 J. Tonry, L. Denneau, H. Weiland (IfA, University of Hawaii) et al. ATLAS ATLAS 04:41:28.869 -02:51:55.79 2025-07-29 03:54:26.784 13.615 orange-ATLAS PSN ATLAS25qmv ATLAS N
274863 2025-10-26 10:20:52 GOTO_bot D. O'Neill, K. Ackley, M. Dyer et al. GOTO GOTO 04:41:28.861 -02:51:55.61 2025-08-15 05:36:58.464 14.51 L-GOTO Other GOTO24ker GOTO N
267605 2025-08-25 12:04:16 BTSbot_bot Nabeel Rehemtulla (CIERA, NU), Wynn Jacobson-Galán (Caltech), Theophile du Laz (Caltech) on behalf of ZTF ZTF ZTF 04:41:28.873 -02:51:55.92 2025-08-17 11:21:27.002 15.4333 g-ZTF PSN ZTF25abjlnnh ZTF Bright (m_peak <= 18.5) transient candidate identified autonomously by BTSbot (Rehemtulla et al. 2024; arXiv:2401.15167). N
265135 2025-08-06 08:44:03 BlackGEM_Bot1 P. Groot, H. Tranin, F. Stoppa et al. BlackGEM BlackGEM 04:41:28.861 -02:51:55.61 2025-07-22 10:22:51.000 13.98 BG-q-BlackGem 1 PSN BGEM J044128.86-025155.6 BlackGEM N
Related files
File Comments Last Modified (UT) Modified By
tns_2025pht_atrep_265135_BlackGEM.pdf Finding Chart 2025-08-06 08:44:05 BlackGEM_Bot1
260520 2025-06-29 14:47:29 Krzysztof Stanek K. Z. Stanek, for the ASAS-SN team ASAS-SN ASAS-SN 04:41:28.834 -02:51:55.87 2025-06-29 10:19:12.000 13.3 g-Sloan PSN NGC 1637 ASASSN-25cw ASAS-SN Bright, nearby SN candidate, present in two epochs, discovered after the seasonal break 2025TNSTR2462....1S N
Classification Reports
ID Time received (UT) Sender Classifier/s Group Classification Redshift Spectra Related files Assoc. Groups End prop. period Remarks ADS Bibcode
21466 2025-07-03 18:37:54 Jay Strader Jay Strader None SN IIP 1 2025TNSCR2547....1S
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
21466 2025-07-03 10:18:06 SOAR / Goodman Jay Strader, Ryan Urquhart None tns_2025pht_2025-07-03_10-18-06_SOAR_Goodman_None.dat Object

Comments

TNS
System

Wed, 08/06/2025 - 08:44

Object coordinates updated

Object coordinates updated according to AT-report 265135 of Group BlackGEM
Previous RA, DEC: 04:41:28.834, -02:51:55.87 (70.37014, -2.86552)
Updated RA, DEC: 04:41:28.861, -02:51:55.61 (70.370254, -2.865447)

Donnie
Hodges

Thu, 07/03/2025 - 22:05

Presumed progenitor visible in HST image

An apparent blue supergiant, a presumed progenitor, is visible very near the coordinates of this SN in the HST image posted on 2 December 2024.

https://esahubble.org/images/potw2449a/

D. Hodges