RA/DEC (2000)
00:38:48.620 +40:46:07.60
9.702583 +40.768778
Type
LRN
Redshift
0
Related AstroNotes: 2026-21
Reporting Group
MASTER
Discovering Data Source
MASTER
Discovery Date
2025-10-19 19:40:11.712
TNS AT
Y
Public
Y
Discovery Mag
17.3
Filter
Other-
Reporter/s
Ya.Kechin, V.Lipunov, E.Gorbovskoy, A.Kuznetsov, K.Zhirkov, I.Panchenko, N.Tiurina, P.Balanutsa, V.Topolev, D.Vlasenko, G.Antipov, A.Sankovich, Yu.Tselik, V.Senik, A.Chasovnikov, K.Labsina, I. Gorbunov (Lomonosov MSU), O.Gress, N.Budnev (ISU), C.Francile, F. Podesta, R.Podesta, E. Gonzalez (Observatorio Astronomico Felix Aguilar (OAFA), A. Tlatov, D. Dormidontov (Kislovodsk Solar Station of the Pulkovo Observatory), A.Sosnovskij (CrAO), A. Gabovich, V.Yurkov (Blagoveschensk Educational StateUniversity), D.Buckley (SAAO), R.Rebolo (The Instituto de Astrofisica de Canarias), L.Carrasco, J.R.Valdes, V.Chavushyan, V.M.Patino Alvarez, J.Martinez, A.R.Corella, L.H.Rodriguez (INAOE, Guillermo Haro Astrophysics Observatory)

Spectra

 AT_2025abao - 2025-10-31 17:16:48 Other / Other (None)z=
 AT_2025abao - 2025-10-29 14:38:24 Other / Other (None)z=
 AT_2025abao - 2025-10-28 21:43:00 BL41 / FOSC-E5535 (None)z=
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   Binning factor: (rounded to nearest integer >1)
Mouse hovers at WL: 0 (rest),

Light curves

 Other_Other_Clear
 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
22347 2025-10-31 17:16:48 Other / Other 1800 Kenta Taguchi None tns_2025abao_2025-10-31.72_Other_Other_None.dat tns_2025abao_2025-10-31.72_Other_Other_None.fits Object See ATel #17468. A spectroscopic follow-up observation with KOOLS-IFU mounted on the 3.8-m Seimei telescope at Okayama Observatory of Kyoto University. The spectral resolution is ~ 500, and the wavelength coverage is 4100-8500 A.
22346 2025-10-29 14:38:24 Other / Other 900 Kenta Taguchi None tns_2025abao_2025-10-29.61_Other_Other_None.dat tns_2025abao_2025-10-29.61_Other_Other_None.fits Object See ATel #17468. A spectroscopic follow-up observation with KOOLS-IFU mounted on the 3.8-m Seimei telescope at Okayama Observatory of Kyoto University. The spectral resolution is ~ 500, and the wavelength coverage is 4100-8500 A.
22903 2025-10-28 21:43:00 BL41 / FOSC-E5535 1800 Claudio Balcon Claudio Balcon None tns_2025abao_2025-10-28_21-43-00_BL41_FOSC-E5535_None.dat tns_2025abao_2025-10-28_21-43-00_BL41_FOSC-E5535_None.fit Object
Light Curves
Filter Tel / Inst Obs-date range JD Range Photometry
Clear- Other_Other 2025-10-22 03:20:24 - 2025-10-22 03:20:24 2460970.63917 - 2460970.63917 1
Photometry
ID Obs-date JD Mag. / Flux Err Lim. Mag./Flux Units Filter Tel / Inst Exp-time Observer/s Remarks
525868 2025-10-22 03:20:24 2460970.63917 16.5 0.2 Other Clear- Other_Other 30 Balaji Kumar Instrument: 14" f/2.0 Astrograph
Other- Other_Other 2015-01-19 12:14:16 - 2025-11-02 00:04:00 2457042.00991 - 2460981.50278 21
Photometry
ID Obs-date JD Mag. / Flux Err Lim. Mag./Flux Units Filter Tel / Inst Exp-time Observer/s Remarks
528491 2025-11-02 00:04:00 2460981.50278 15.1 17.5 VegaMag Other- Other_Other 60 Robot MASTER-Tavrida
528490 2025-11-01 23:57:47 2460981.49846 15.1 17.7 VegaMag Other- Other_Other 60 Robot MASTER-Tavrida
529117 2025-10-31 02:13:57 2460979.59302 15.5 18.3 VegaMag Other- Other_Other 60 Robot MASTER-OAFA
529116 2025-10-31 02:12:40 2460979.59213 15.5 18.2 VegaMag Other- Other_Other 60 Robot MASTER-OAFA
527591 2025-10-28 21:16:34 2460977.3865 15.1 17.5 VegaMag Other- Other_Other 60 Robot MASTER-SAAO
527590 2025-10-28 21:15:01 2460977.38543 15.2 17.5 VegaMag Other- Other_Other 60 Robot MASTER-SAAO
526315 2025-10-23 20:01:18 2460972.33424 14.9 18.2 VegaMag Other- Other_Other 60 Robot MASTER-Tunka
526318 2025-10-23 19:45:20 2460972.32315 15.5 19.1 VegaMag Other- Other_Other 180 Robot MASTER-Tunka
526314 2025-10-23 19:37:58 2460972.31803 14.9 18.3 VegaMag Other- Other_Other 60 Robot MASTER-Tunka
526317 2025-10-23 19:34:22 2460972.31553 15.5 19.3 VegaMag Other- Other_Other 180 Robot MASTER-Tunka
529115 2025-10-23 02:15:37 2460971.59418 19.3 VegaMag Other- Other_Other 60 Robot [Last non detection] MASTER-OAFA
526321 2025-10-21 15:03:39 2460970.12754 16.3 19.8 VegaMag Other- Other_Other 60 Robot MASTER-Tunka
526320 2025-10-21 14:52:18 2460970.11965 16.3 19.9 VegaMag Other- Other_Other 60 Robot MASTER-Tunka
525277 2025-10-19 19:43:32 2460968.3219 17.4 19.2 VegaMag Other- Other_Other 180 Robot MASTER-Kislovodsk
525276 2025-10-19 19:40:12 2460968.31958 17.3 19.1 VegaMag Other- Other_Other 180 Robot MASTER-Kislovodsk
526319 2025-09-18 18:53:24 2460937.28708 20.9 VegaMag Other- Other_Other 180 Robot [Last non detection] MASTER-Tunka
527589 2024-06-25 04:25:17 2460486.68422 17.6 VegaMag Other- Other_Other 60 Robot [Last non detection] MASTER-SAAO
528489 2023-08-27 23:44:21 2460184.48913 21 VegaMag Other- Other_Other 540 Robot [Last non detection] MASTER-Tavrida
525275 2016-10-04 20:41:09 2457666.36191 21.3 VegaMag Other- Other_Other 540 Robot [Last non detection] MASTER-Kislovodsk
526316 2015-01-19 12:54:18 2457042.03771 19.2 VegaMag Other- Other_Other 180 Robot [Last non detection] MASTER-Tunka
526313 2015-01-19 12:14:16 2457042.00991 18.8 VegaMag Other- Other_Other 540 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
275812 2025-11-05 01:07:05 MASTER M.Shilova,V.Lipunov,E.Gorbovskoy et al. MASTER MASTER 00:38:48.620 +40:46:07.60 2025-10-31 02:12:40.032 15.5 Other- Other MASTER OT J003848.62+404607.6 MASTER Blue, Johnson/Bessel N
275510 2025-11-02 00:15:06 MASTER A.Sosnovskij (CRAO RAS),V.Lipunov,E.Gorbovskoy et al. MASTER MASTER 00:38:48.620 +40:46:08.30 2025-11-01 23:57:46.944 15.1 Other- Other MASTER OT J003848.62+404608.3 MASTER unfilteres N
275128 2025-10-29 10:49:13 MASTER G.Antipov,V.Lipunov,E.Gorbovskoy et al. MASTER MASTER 00:38:48.610 +40:46:08.00 2025-10-28 21:15:01.152 15.2 Other- Other MASTER OT J003848.61+404608.0 MASTER V-band (Johnson|Bessel) N
274560 2025-10-23 23:57:26 MASTER Ya.Kechin,V.Lipunov,E.Gorbovskoy et al. MASTER MASTER 00:38:48.670 +40:46:07.60 2025-10-21 14:52:17.760 16.3 Other- PNV MASTER OT J003848.67+404607.6 MASTER unfiltered N
274559 2025-10-23 23:12:53 MASTER P.Balanutsa,O.Gress,Ya.Kechin et al. MASTER MASTER 00:38:48.630 +40:46:08.40 2025-10-23 19:34:21.792 15.5 Other- PSN MASTER OT J003848.63+404608.4 MASTER V-band N
274558 2025-10-23 23:11:50 MASTER O.Gress,Ya.Kechin,P.Balanutsa et al. MASTER MASTER 00:38:48.580 +40:46:08.40 2025-10-23 19:37:57.792 14.9 Other- Other MASTER OT J003848.58+404608.4 MASTER I band N
274337 2025-10-23 04:16:56 GEOTS_Bot Balaji Kumar et al. GEOTS GEOTS 00:38:48.610 +40:46:08.60 2025-10-22 03:20:24.288 16.5 Clear- PSN GEOTS-Balaji-2025-M31-1022 GEOTS Discovered in And using 14" f/2.0 Astrograph at Golden Ears Observatory (MPC code U55). N
Related files
File Comments Last Modified (UT) Modified By
tns_2025abao_atrep_274337_GEOTS.png Discovery image 2025-10-23 04:16:57 GEOTS_Bot
274097 2025-10-20 18:55:36 MASTER Ya.Kechin,V.Lipunov,E.Gorbovskoy et al. MASTER MASTER 00:38:48.650 +40:46:07.50 2025-10-19 19:40:11.712 17.3 Other- PNV MASTER OT J003848.65+404607.5 MASTER 2025TNSTR4205....1K N
Classification Reports
ID Time received (UT) Sender Classifier/s Group Classification Redshift Spectra Related files Assoc. Groups End prop. period Remarks ADS Bibcode
22902 2026-02-03 10:57:01 Claudio Balcon Claudio Balcon (Belluno A.O. ISSP) None LRN 0 1 The spectrum shows a blue continuum with Balmer emission lines. 2026TNSCR.460....1B
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
22903 2025-10-28 21:43:00 BL41 / FOSC-E5535 1800 Claudio Balcon Claudio Balcon None tns_2025abao_2025-10-28_21-43-00_BL41_FOSC-E5535_None.dat tns_2025abao_2025-10-28_21-43-00_BL41_FOSC-E5535_None.fit Object
22346 2025-11-02 15:55:49 Kenta Taguchi Kenta Taguchi (Kyoto University), Keiichi Maeda (Kyoto University) None LRN 2 See ATel #17468. Our spectra taken by Seimei/KOOLS-IFU are dominated by a blue continuum. The emission line of Hα is prominently seen in both epochs (with Lorentzian FWHM ∼ 630 and 700 km/s on 2025-10-29.61 and 2025-10-31.72, respectively), while Hβ is only prominent on 2025-10-29.61 but has significantly weakened on 2025-10-31.72. The absorption line of NaI D is clearly seen in both epochs, suggesting that this object suffers from extinction. The evolution is similar to that of the luminous red nova AT 2019zhd, reported by Pastorello et al. (2021). From this similarity and the luminosity of the optical event, we propose that this event is likely a luminous red nova in M31, consistent with the common-envelope transient scenario of WNTR23bzdiq proposed by Karambelkar et al. (2025). 2025TNSCR4414....1T
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
22347 2025-10-31 17:16:48 Other / Other 1800 Kenta Taguchi None tns_2025abao_2025-10-31.72_Other_Other_None.dat tns_2025abao_2025-10-31.72_Other_Other_None.fits Object See ATel #17468. A spectroscopic follow-up observation with KOOLS-IFU mounted on the 3.8-m Seimei telescope at Okayama Observatory of Kyoto University. The spectral resolution is ~ 500, and the wavelength coverage is 4100-8500 A.
22346 2025-10-29 14:38:24 Other / Other 900 Kenta Taguchi None tns_2025abao_2025-10-29.61_Other_Other_None.dat tns_2025abao_2025-10-29.61_Other_Other_None.fits Object See ATel #17468. A spectroscopic follow-up observation with KOOLS-IFU mounted on the 3.8-m Seimei telescope at Okayama Observatory of Kyoto University. The spectral resolution is ~ 500, and the wavelength coverage is 4100-8500 A.

Comments

TNS
System

Object coordinates updated

Object coordinates updated according to AT-report 275812 of Group MASTER
Previous RA, DEC: 00:38:48.620, +40:46:08.30 (9.702583, +40.768972)
Updated RA, DEC: 00:38:48.620, +40:46:07.60 (9.702583, +40.768778)

TNS
System

Object coordinates updated

Object coordinates updated according to AT-report 275510 of Group MASTER
Previous RA, DEC: 00:38:48.610, +40:46:08.00 (9.702542, +40.768889)
Updated RA, DEC: 00:38:48.620, +40:46:08.30 (9.702583, +40.768972)

TNS
System

Object coordinates updated

Object coordinates updated according to AT-report 275128 of Group MASTER
Previous RA, DEC: 00:38:48.670, +40:46:07.60 (9.702792, +40.768778)
Updated RA, DEC: 00:38:48.610, +40:46:08.00 (9.702542, +40.768889)

TNS
System

Object coordinates updated

Object coordinates updated according to AT-report 274560 of Group MASTER
Previous RA, DEC: 00:38:48.630, +40:46:08.40 (9.702625, +40.769)
Updated RA, DEC: 00:38:48.670, +40:46:07.60 (9.702792, +40.768778)

TNS
System

Object coordinates updated

Object coordinates updated according to AT-report 274559 of Group MASTER
Previous RA, DEC: 00:38:48.580, +40:46:08.40 (9.702417, +40.769)
Updated RA, DEC: 00:38:48.630, +40:46:08.40 (9.702625, +40.769)

TNS
System

Object coordinates updated

Object coordinates updated according to AT-report 274558 of Group MASTER
Previous RA, DEC: 00:38:48.650, +40:46:07.50 (9.702708, +40.76875)
Updated RA, DEC: 00:38:48.580, +40:46:08.40 (9.702417, +40.769)