RA/DEC (2000)
07:40:59.037 +16:31:53.62
115.2459858 +16.5315623
Type
TDE
Redshift
0.101
Discovery ReportClassification Report
Related AstroNotes: 2025-71, 2025-116
Reporting Group
ZTF
Discovering Data Source
ZTF
Discovery Date
2025-02-20 08:39:00.996
TNS AT
Y
Public
Y
Discovery Mag
19.5231
Filter
g-ZTF
Reporter/s
Jesper Sollerman (SU), Christoffer Fremling (Caltech), Daniel Perley (LJMU), Theophile du Laz (Caltech) on behalf of ZTF
NEDSIMBADDECaLSPanSTARRS-1SkyMapperVizieRWISEDSSADS

Spectra

 ▌TDE_2025chm - 2025-02-27 21:54:07 NOT / ALFOSC (None)z=
▌Show H at z=vexp= km/s
▌Show He at z=vexp= km/s
▌Show He II at z=vexp= km/s
▌Show C II at z=vexp= km/s
▌Show C III at z=vexp= km/s
▌Show C IV at z=vexp= km/s
▌Show N II at z=vexp= km/s
▌Show N III at z=vexp= km/s
▌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
▌Show O II at z=vexp= km/s
▌Show [O II] at z=vexp= km/s
▌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

 ▌GOTO-N_GOTO-1_L
 ▌P48_ZTF-Cam_r
 ▌P48_ZTF-Cam_g
 ▌ATLAS-HKO_ATLAS-02_orange
   
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
20496 2025-02-27 21:54:07 NOT / ALFOSC 900 Roar Alejandra Saskia Panos Charalampopoulos None tns_2025chm_2025-02-27_21-54-07.321_NOT_ALFOSC_None.ascii tns_2025chm_2025-02-27_21-54-07.321_NOT_ALFOSC_None.fits Object
Light Curves
Filter Tel / Inst Obs-date range JD Range Photometry
L-GOTO GOTO-N_GOTO-1 2025-02-12 20:38:26 - 2025-02-16 21:05:26 2460719.360015 - 2460723.37877 2
Photometry
ID Obs-date JD Mag. / Flux Err Lim. Mag./Flux Units Filter Tel / Inst Exp-time Observer/s Remarks
471499 2025-02-16 21:05:26 2460723.37877 19.58 0.2 ABMag L-GOTO GOTO-N_GOTO-1 180
471498 2025-02-12 20:38:26 2460719.360015 18.4 ABMag L-GOTO GOTO-N_GOTO-1 180 [Last non detection]
r-ZTF P48_ZTF-Cam 2025-02-18 07:18:38 - 2025-02-18 07:18:38 2460724.8046065 - 2460724.8046065 1
Photometry
ID Obs-date JD Mag. / Flux Err Lim. Mag./Flux Units Filter Tel / Inst Exp-time Observer/s Remarks
470586 2025-02-18 07:18:38 2460724.8046065 19.9367 ABMag r-ZTF P48_ZTF-Cam [Last non detection]
g-ZTF P48_ZTF-Cam 2025-02-20 08:39:01 - 2025-02-22 06:07:36 2460726.8604282 - 2460728.7552778 2
Photometry
ID Obs-date JD Mag. / Flux Err Lim. Mag./Flux Units Filter Tel / Inst Exp-time Observer/s Remarks
470588 2025-02-22 06:07:36 2460728.7552778 19.1084 0.0796883 ABMag g-ZTF P48_ZTF-Cam
470587 2025-02-20 08:39:01 2460726.8604282 19.5231 0.143443 ABMag g-ZTF P48_ZTF-Cam
orange-ATLAS ATLAS-HKO_ATLAS-02 2025-02-23 09:02:49 - 2025-02-24 06:30:26 2460729.87696 - 2460730.77113 2
Photometry
ID Obs-date JD Mag. / Flux Err Lim. Mag./Flux Units Filter Tel / Inst Exp-time Observer/s Remarks
471521 2025-02-24 06:30:26 2460730.77113 19.075 0.167 19.36 ABMag orange-ATLAS ATLAS-HKO_ATLAS-02 30 Robot
471520 2025-02-23 09:02:49 2460729.87696 19.43 ABMag orange-ATLAS ATLAS-HKO_ATLAS-02 30 Robot [Last non detection]
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
245822 2025-02-24 21:52:07 ATLAS_Bot1 J. Tonry,L. Denneau,H. Weiland et al. ATLAS ATLAS 07:40:59.046 +16:31:53.62 2025-02-24 06:30:25.632 19.075 orange-ATLAS PSN ATLAS25bzy ATLAS N
245811 2025-02-24 20:45:52 GOTO_bot D. O'Neill,G. Ramsay,K. Ackley et al. GOTO GOTO 07:40:59.069 +16:31:53.80 2025-02-16 21:05:25.728 19.58 L-GOTO Other GOTO25asg GOTO N
245377 2025-02-22 06:38:57 Fritz Jesper Sollerman (SU),Christoffer Fremling (Caltech),Daniel Perley (LJMU) et al. ZTF ZTF 07:40:59.037 +16:31:53.62 2025-02-20 08:39:00.996 19.5231 g-ZTF PSN ZTF25aagevje ZTF 2025TNSTR.725....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
20496 2025-02-28 11:19:25 Panos Charalampopoulos Panos Charalampopoulos None TDE 0.101 1 3 We report the classification of AT2025chm as a Tidal Disruption Event (TDE) based on an optical spectrum obtained with the Nordic Optical Telescope on 2025-02-27 (i.e., MJD 60733.91). The transient appears coincident with the host nucleus. At a redshift of 0.101, we tentatively identify CaII H&K and Hbeta absorption but we note that the redshift might be down to ~ 0.085. We detect broad Halpha, and a blend of broad Hbeta and HeII 4686. Comparison with a library of supernovae spectra using NGSF (Next Generation SuperFit; AstroNote 2022-191, Howell et al. 2005 2005ApJ...634.1190H), suggests AT2025chm is an around peak TDE (see attached images). We note that there is significant MW extinction (Av=0.10) which would make the g-r constant colour evolution to be around -0.35. At that redshift, and correcting for the MW extinction, the current absolute r-band magnitude is Mr ~ -19.4. 2025TNSCR.836....1C
Related files
File Comments Last Modified (UT) Modified By
tns_2025chm_atrep_20496.pdf Classifications were done using NGSF (Next Generation SuperFit; AstroNote 2022-191, Howell et al. 2005 2005ApJ...634.1190H). 2025-02-28 14:48:42 Panos Charalampopoulos
tns_2025chm_atrep_20496_0.pdf Classifications were done using NGSF (Next Generation SuperFit; AstroNote 2022-191, Howell et al. 2005 2005ApJ...634.1190H). 2025-02-28 14:48:58 Panos Charalampopoulos
tns_2025chm_atrep_20496_1.pdf Classifications were done using NGSF (Next Generation SuperFit; AstroNote 2022-191, Howell et al. 2005 2005ApJ...634.1190H). 2025-02-28 14:49:05 Panos Charalampopoulos
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
20496 2025-02-27 21:54:07 NOT / ALFOSC 900 Roar Alejandra Saskia Panos Charalampopoulos None tns_2025chm_2025-02-27_21-54-07.321_NOT_ALFOSC_None.ascii tns_2025chm_2025-02-27_21-54-07.321_NOT_ALFOSC_None.fits Object

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