RA/DEC (2000)
14:37:16.143 +71:50:30.32
219.317260634 +71.8417543772
Type
Afterglow
Redshift
0.153
Discovery ReportClassification Report
Related AstroNotes: 2026-65
Reporting Group
GOTO
Discovering Data Source
GOTO
Discovery Date
2026-03-10 05:14:30.624
TNS AT
Y
Public
Y
Discovery Mag
18.84
Filter
L-GOTO
Reporter/s
D. O'Neill, G. Ramsay, K. Ackley, M. Dyer, J. Lyman, K. Ulaczyk, D. Steeghs, D. Galloway, V. Dhillon, P. O'Brien, K. Noysena, R. Kotak, R. Breton, J. Casares, L. Nuttall, R. Starling, B. Gompertz, B. Godson, T. Killestein, A. Kumar, M. Pursiainen, on behalf of GOTO collaboration
NEDSIMBADDECaLSPanSTARRS-1SkyMapperVizieRWISEDSSADS

Spectra

 ▌AT_2026fgk - 2025-03-13 06:02:24 Bok / BC-Bok (AZTEC)z=
▌Show H at z=vexp= km/s
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▌Show N II at z=vexp= km/s
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▌Show N IV at z=vexp= km/s
▌Show N V at z=vexp= km/s
▌Show O at z=vexp= km/s
▌Show [O I] at z=vexp= km/s
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▌Show [O III] at z=vexp= km/s
▌Show O V at z=vexp= km/s
▌Show O VI at z=vexp= km/s
▌Show Na at z=vexp= km/s
▌Show Mg at z=vexp= km/s
▌Show Mg II at z=vexp= km/s
▌Show Si II at z=vexp= km/s
▌Show S II at z=vexp= km/s
▌Show Ca II at z=vexp= km/s
▌Show [Ca II] at z=vexp= km/s
▌Show Fe II at z=vexp= km/s
▌Show Fe III at z=vexp= km/s
▌Show Å at z=vexp= km/s
▌Show Å at z=vexp= km/s
▌Show Å at z=vexp= km/s
▌Show Å at z=vexp= km/s
▌Show Tellurics 
▌Show Galaxy lines at z=
▌Show WR-WN at z=vexp= km/s
▌Show WR-WC/O at z=vexp= km/s
   Binning factor: (rounded to nearest integer >1)
Mouse hovers at WL: 0 (rest),0 (observed)

Light curves

 ▌ATLAS-TDO_ATLAS-05_wide
 ▌GOTO-N_GOTO-2_L
 ▌PS2_GPC2_g
 ▌GOTO-N_GOTO-1_L
 ▌P48_ZTF-Cam_r
 ▌P48_ZTF-Cam_g
 ▌ATLAS-MLO_ATLAS-01_orange
 ▌Other_Other_Other
   
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
23211 2025-03-13 06:02:24 Bok / BC-Bok 6000 Brian Hsu Brian Hsu AZTEC tns_2026fgk_2025-03-13_06-02-24_Bok_BC-Bok_AZTEC.txt Object The strong emission line near 5577 Angstrom is an unsubtracted sky line and not associated with the candidate host galaxy.
Light Curves
Filter Tel / Inst Obs-date range JD Range Photometry
wide-ATLAS ATLAS-TDO_ATLAS-05 2026-03-09 04:04:30 - 2026-03-09 04:04:30 2461108.66979 - 2461108.66979 1
Photometry
ID Obs-date JD Mag. / Flux Err Lim. Mag./Flux Units Filter Tel / Inst Exp-time Observer/s Remarks
564112 2026-03-09 04:04:30 2461108.66979 19.5 ABMag wide-ATLAS ATLAS-TDO_ATLAS-05 30 Robot [Last non detection]
L-GOTO GOTO-N_GOTO-2 2025-07-17 22:23:39 - 2025-07-17 22:23:39 2460874.433092 - 2460874.433092 1
Photometry
ID Obs-date JD Mag. / Flux Err Lim. Mag./Flux Units Filter Tel / Inst Exp-time Observer/s Remarks
563894 2025-07-17 22:23:39 2460874.433092 18.6 ABMag L-GOTO GOTO-N_GOTO-2 180 [Last non detection]
g-P1 PS2_GPC2 2026-04-01 12:53:31 - 2026-04-01 12:53:31 2461132.03716 - 2461132.03716 1
Photometry
ID Obs-date JD Mag. / Flux Err Lim. Mag./Flux Units Filter Tel / Inst Exp-time Observer/s Remarks
571966 2026-04-01 12:53:31 2461132.03716 20.71 0.22 21 ABMag g-P1 PS2_GPC2 300 Robot
L-GOTO GOTO-N_GOTO-1 2026-03-10 05:14:31 - 2026-03-10 05:14:31 2461109.718406 - 2461109.718406 1
Photometry
ID Obs-date JD Mag. / Flux Err Lim. Mag./Flux Units Filter Tel / Inst Exp-time Observer/s Remarks
563895 2026-03-10 05:14:31 2461109.718406 18.84 0.06 ABMag L-GOTO GOTO-N_GOTO-1 360
r-ZTF P48_ZTF-Cam 2026-03-11 11:49:23 - 2026-03-11 11:49:23 2461110.9926273 - 2461110.9926273 1
Photometry
ID Obs-date JD Mag. / Flux Err Lim. Mag./Flux Units Filter Tel / Inst Exp-time Observer/s Remarks
564029 2026-03-11 11:49:23 2461110.9926273 17.6421 0.0488318 ABMag r-ZTF P48_ZTF-Cam
g-ZTF P48_ZTF-Cam 2026-03-09 05:41:01 - 2026-03-11 09:43:41 2461108.7368171 - 2461110.9053356 2
Photometry
ID Obs-date JD Mag. / Flux Err Lim. Mag./Flux Units Filter Tel / Inst Exp-time Observer/s Remarks
564028 2026-03-11 09:43:41 2461110.9053356 18.0762 0.0591847 ABMag g-ZTF P48_ZTF-Cam
564027 2026-03-09 05:41:01 2461108.7368171 20.3664 ABMag g-ZTF P48_ZTF-Cam [Last non detection]
orange-ATLAS ATLAS-MLO_ATLAS-01 2026-03-10 12:05:32 - 2026-03-10 12:05:32 2461110.00384 - 2461110.00384 1
Photometry
ID Obs-date JD Mag. / Flux Err Lim. Mag./Flux Units Filter Tel / Inst Exp-time Observer/s Remarks
564113 2026-03-10 12:05:32 2461110.00384 16.65 0.029 19.32 ABMag orange-ATLAS ATLAS-MLO_ATLAS-01 30 Robot
Other- Other_Other 2011-02-25 18:25:32 - 2026-03-12 14:16:00 2455618.26773 - 2461112.09444 3
Photometry
ID Obs-date JD Mag. / Flux Err Lim. Mag./Flux Units Filter Tel / Inst Exp-time Observer/s Remarks
564311 2026-03-12 14:16:00 2461112.09444 18.3 20.2 VegaMag Other- Other_Other 60 Robot MASTER-Tunka
564310 2026-03-12 14:14:47 2461112.0936 18.3 20.1 VegaMag Other- Other_Other 60 Robot MASTER-Tunka
564309 2011-02-25 18:25:32 2455618.26773 21.8 VegaMag Other- Other_Other 180 Robot [Last non detection] MASTER-Tunka
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
298340 2026-04-03 15:11:18 PS1_Bot1 K. C. Chambers, T. de Boer, J. Fairlamb et al. Pan-STARRS Pan-STARRS 14:37:16.143 +71:50:30.32 2026-04-01 12:53:30.624 20.71 g-P1 PSN PS26aru Pan-STARRS N
294310 2026-03-12 15:25:50 MASTER N.Budnev, O.Gress, V.Lipunov et al. MASTER MASTER 14:37:16.190 +71:50:31.20 2026-03-12 14:14:47.040 18.3 Other- PSN MASTER OT J143716.19+715031.2 MASTER unfiltered N
294228 2026-03-11 23:17:50 ATLAS_Bot1 J. Tonry, L. Denneau, H. Weiland (IfA, University of Hawaii) et al. ATLAS ATLAS 14:37:16.127 +71:50:30.31 2026-03-10 12:05:31.776 16.65 orange-ATLAS PSN ATLAS26cwg ATLAS N
294188 2026-03-11 13:00:10 Fritz Jesper Sollerman (SU), Christoffer Fremling (Caltech), Daniel Perley (LJMU) et al. ZTF ZTF 14:37:16.141 +71:50:30.32 2026-03-11 09:43:40.995 18.0762 g-ZTF PSN ZTF26aakjzdt ZTF N
294132 2026-03-10 21:03:55 GOTO_bot D. O'Neill, G. Ramsay, K. Ackley et al. GOTO GOTO 14:37:16.290 +71:50:30.11 2026-03-10 05:14:30.624 18.84 L-GOTO Other GOTO26buh GOTO 2026TNSTR1001....1O N
Classification Reports
ID Time received (UT) Sender Classifier/s Group Classification Redshift Spectra Related files Assoc. Groups End prop. period Remarks ADS Bibcode
23357 2026-03-27 07:25:46 Antonio de Ugarte Postigo Antonio de Ugarte Postigo (LAM), Stefan Geier (GTC), Luca Izzo (INAF/OACN and DARK/NBI), Daniele B. Malesani (DAWN/NBI and Radboud), Antonio Martin-Carrillo (UCD), Christina C. Thoene (AbAO), Miguel Angel Aloy (UV), Johan P. U. Fynbo (DAWN/NBI), Lluis Galbany (IEEC-CSIC), Gianluca Lombardi (GTC), Ny Avo Rakotondrainibe (LAM), Benjamin Schneider (LAM), Nial R. Tanvir (Univ. Leicester), Daniel González González (GTC) None SN Ic-BL 0.153 2027-03-27 The spectrum has evolved from the power-law continuum of the afterglow and now shows undulations expected in a supernova spectrum. Indeed, using SNID to classify the SN we get a best match to a Ic-BL close to maximum light. Our results allow us to conclusively identify the presence of a SN, linking the event to a massive stellar collapse.
23210 2026-03-13 13:28:39 Brian Hsu Brian Hsu (U of Arizona), M. Shrestha (Monash U), D. J. Sand (U of Arizona), Jennifer Andrews (Gemini-N/NOIRLab), N. Franz (U of Arizona), J. Pearson (U of Arizona), C. Christy (U of Arizona), C. L. Ransome (U of Arizona), Bhagya Subrayan (U of Arizona), K. Bostroem (U of Arizona), G. Hosseinzadeh (UCSD), N. Smith (U of Arizona) on behalf of the AZTEC collaboration AZTEC Afterglow 0.153 1 AZTEC We report the classification of AT 2026fgk as the possible optical counterpart to GRB 260310A (Konno et al., GCN 43974; Lipunov et al., GCN 43978, discovered by GOTO; O'Neill et al. 2026, TNS Discovery Report 294132) based on the optical spectrum obtained on UT 2025-03-13T06:02:23.850 using the B&C spectrograph on the 90-inch Bok telescope. The optical counterpart is clearly visible. The optical spectrum shows a featureless red continuum, although there is a strong, narrow emission line at 7566 Angstroms that we attribute to H-alpha from the candidate host galaxy at z = 0.153, which is in agreement with the redshift obtained by Hinds et al., GCN 43977. Additional follow-up observations are encouraged. 2026TNSCR1062....1H
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
23211 2025-03-13 06:02:24 Bok / BC-Bok 6000 Brian Hsu Brian Hsu AZTEC tns_2026fgk_2025-03-13_06-02-24_Bok_BC-Bok_AZTEC.txt Object The strong emission line near 5577 Angstrom is an unsubtracted sky line and not associated with the candidate host galaxy.

Comments

TNS
System

Fri, 04/03/2026 - 15:11

Object coordinates updated

Object coordinates updated according to AT-report 298340 of Group Pan-STARRS
Previous RA, DEC: 14:37:16.141, +71:50:30.32 (219.3172543, +71.8417549)
Updated RA, DEC: 14:37:16.143, +71:50:30.32 (219.317260634, +71.8417543772)

TNS
System

Wed, 03/11/2026 - 13:00

Object coordinates updated

Object coordinates updated according to AT-report 294188 of Group ZTF
Previous RA, DEC: 14:37:16.290, +71:50:30.11 (219.317875, +71.841698)
Updated RA, DEC: 14:37:16.141, +71:50:30.32 (219.3172543, +71.8417549)