2025xsm | Transient Name Server

RA/DEC (2000)

04:18:27.632 -54:38:25.29

64.615133 -54.640358

Type

SN Ia

Redshift

0.04

Discovery Report Classification Report

Reporting Group

BlackGEM

Discovering Data Source

BlackGEM

Discovery Date

2025-09-13 09:22:38.000

TNS AT

Public

Discovery Mag

17.74

Filter

BG-q-BlackGem

Reporter/s

H. Tranin, F. Stoppa, D. Pieterse, G. Ramsay, S. Faris, P. Groot, P. Vreeswijk, N. Blagorodnova, J. van Roestel, H. Wichern, S. Scaringi

NED SIMBAD DECaLS PanSTARRS-1 SkyMapper VizieR WISE DSS ADS

Light curves

▌

GOTO-S_GOTO-4_L

▌

BG3_BlackGEM-Cam3_BG-q

Pointer position (MJD, Mag, Abs.Mag): (0.00, 0.00, 0.00)

Spectra

Select	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
	22053	2025-09-18 22:24:33	Lesedi / Mookodi	900	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_2025xsm_2025-09-18_22-24-32.650_Lesedi_Mookodi_BlackGEM.csv		Object			The spectrum was taken with the SAAO's 1-m Lesedi robotic 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
Binning factor: (rounded to nearest integer >1) Mouse hovers at WL: 0 (rest), 0 (observed) ▌Show H at z=v_exp= km/s ▌Show He at z=v_exp= km/s ▌Show He II at z=v_exp= km/s ▌Show C II at z=v_exp= km/s ▌Show C III at z=v_exp= km/s ▌Show C IV at z=v_exp= km/s ▌Show N II at z=v_exp= km/s ▌Show N III at z=v_exp= km/s ▌Show N IV at z=v_exp= km/s ▌Show N V at z=v_exp= km/s ▌Show O at z=v_exp= km/s ▌Show [O I] at z=v_exp= km/s ▌Show O II at z=v_exp= km/s ▌Show [O II] at z=v_exp= km/s ▌Show [O III] at z=v_exp= km/s ▌Show O V at z=v_exp= km/s ▌Show O VI at z=v_exp= km/s ▌Show Na at z=v_exp= km/s ▌Show Mg at z=v_exp= km/s ▌Show Mg II at z=v_exp= km/s ▌Show Si II at z=v_exp= km/s ▌Show S II at z=v_exp= km/s ▌Show Ca II at z=v_exp= km/s ▌Show [Ca II] at z=v_exp= km/s ▌Show Fe II at z=v_exp= km/s ▌Show Fe III at z=v_exp= km/s ▌Show Å at z=v_exp= km/s ▌Show Å at z=v_exp= km/s ▌Show Å at z=v_exp= km/s ▌Show Å at z=v_exp= km/s ▌Show Tellurics ▌Show Galaxy lines at z= ▌Show WR-WN at z=v_exp= km/s ▌Show WR-WC/O at z=v_exp= km/s Remarks The spectrum was taken with the SAAO's 1-m Lesedi robotic 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

2025-08-12 16:43:49 - 2025-09-03 15:43:02

2460900.197092 - 2460922.154878

Photometry

ID	Obs-date	JD	Mag. / Flux	Err	Lim. Mag./Flux	Units	Filter	Tel / Inst	Exp-time	Observer/s	Remarks
517944	2025-09-03 15:43:02	2460922.154878	19.09	0.19		ABMag	L-GOTO	GOTO-S_GOTO-4	180
517943	2025-08-12 16:43:49	2460900.197092			19.3	ABMag	L-GOTO	GOTO-S_GOTO-4	180		[Last non detection]

BG-q-BlackGem

BG3_BlackGEM-Cam3

2025-09-03 08:01:03 - 2025-09-13 09:22:38

2460921.8340625 - 2460931.8907176

Photometry

ID	Obs-date	JD	Mag. / Flux	Err	Lim. Mag./Flux	Units	Filter	Tel / Inst	Exp-time	Observer/s	Remarks
517777	2025-09-13 09:22:38	2460931.8907176	17.74	0.06	20.34	ABMag	BG-q-BlackGem	BG3_BlackGEM-Cam3	60	robotic
517776	2025-09-03 08:01:03	2460921.8340625			20.42	ABMag	BG-q-BlackGem	BG3_BlackGEM-Cam3	60	robotic	[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
270405	2025-09-17 07:10:54	GOTO_bot	S. Belkin, G. Ramsay, K. Ackley et al.	GOTO	GOTO	04:18:27.613	-54:38:25.33	2025-09-03 15:43:01.632	19.09	L-GOTO		Other		GOTO25hdy	GOTO				N
270346	2025-09-16 17:28:02	BlackGEM_Bot1	H. Tranin, F. Stoppa, D. Pieterse et al.	BlackGEM	BlackGEM	04:18:27.632	-54:38:25.29	2025-09-13 09:22:38.000	17.74	BG-q-BlackGem		PSN		BGEM J041827.63-543825.3	BlackGEM			2025TNSTR3718....1T	N

Classification Reports

Time received (UT)

Sender

Classifier/s

Group

Classification

Redshift

Spectra

Related files

Assoc. Groups

End prop. period

Remarks

ADS Bibcode

22053

2025-09-19 07:19:17

Simon de Wet

BlackGEM

SN Ia

0.04

BlackGEM

SNID SAGE (Stoppa, in prep, 2025) shows matches to Type Ia SN spectra at z=0.04.

2025TNSCR3773....1d

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
22053	2025-09-18 22:24:33	Lesedi / Mookodi	900	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_2025xsm_2025-09-18_22-24-32.650_Lesedi_Mookodi_BlackGEM.csv		Object			The spectrum was taken with the SAAO's 1-m Lesedi robotic 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

SN 2025xsm

Spectra

Light curves

Comments