2025umq | Transient Name Server

RA/DEC (2000)

00:48:18.875 +07:59:00.67

12.078646 +7.983519

Type

SN Ia

Redshift

0.159

Discovery Report Classification Report

Reporting Group

F. D. Romanov

Discovering Data Source

F. D. Romanov

Discovery Date

2025-08-17 15:00:24.000

TNS AT

Public

Host Name

SDSS J004819.14+075856.8

Discovery Mag

19.6

Filter

Clear-

Reporter/s

Filipp Romanov

NED SIMBAD DECaLS PanSTARRS-1 SkyMapper VizieR WISE DSS ADS

Light curves

▌

LT_IO-O_i

▌

LT_IO-O_r

▌

LT_IO-O_g

▌

Other_Other_Clear

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
	21875	2025-08-20 03:06:46	LT / SPRAT	3400	F. D. Romanov		F. D. Romanov	tns_AT_2025umq_2025-08-20_03-06-46_LT_SPRAT_F._D._Romanov.txt	tns_AT_2025umq_2025-08-20_03-06-46_LT_SPRAT_F._D._Romanov.fit	Object
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

Light Curves

Filter

Tel / Inst

Obs-date range

JD Range

Photometry

i-Sloan

LT_IO-O

2025-08-23 04:24:47 - 2025-08-24 03:57:59

2460910.6838804 - 2460911.6652745

Photometry

ID	Obs-date	JD	Mag. / Flux	Err	Lim. Mag./Flux	Units	Filter	Tel / Inst	Exp-time	Observer/s	Remarks
512595	2025-08-24 03:57:59	2460911.6652745	21.08	0.15		ABMag	i-Sloan	LT_IO-O	180	F. D. Romanov
512594	2025-08-23 04:24:47	2460910.6838804	20.66	0.13		ABMag	i-Sloan	LT_IO-O	120	F. D. Romanov

r-Sloan

LT_IO-O

2025-08-19 03:49:12 - 2025-08-24 03:53:57

2460906.6591667 - 2460911.6624644

Photometry

ID	Obs-date	JD	Mag. / Flux	Err	Units	Filter	Tel / Inst	Exp-time	Observer/s	Remarks
512593	2025-08-24 03:53:57	2460911.6624644	20.49	0.12	ABMag	r-Sloan	LT_IO-O	180	F. D. Romanov
512592	2025-08-23 04:21:23	2460910.6815235	20.63	0.15	ABMag	r-Sloan	LT_IO-O	120	F. D. Romanov
510288	2025-08-19 03:49:12	2460906.6591667	20.3	0.1	ABMag	r-Sloan	LT_IO-O	300	F. D. Romanov	Compared to r magnitudes of nearby stars from Pan-STARRS DR1 catalogue (Chambers et al., 2016).

g-Sloan

LT_IO-O

2025-08-23 04:17:59 - 2025-08-24 03:49:52

2460910.6791454 - 2460911.6596276

Photometry

ID	Obs-date	JD	Mag. / Flux	Err	Lim. Mag./Flux	Units	Filter	Tel / Inst	Exp-time	Observer/s	Remarks
512591	2025-08-24 03:49:52	2460911.6596276	21.07	0.15		ABMag	g-Sloan	LT_IO-O	180	F. D. Romanov
512590	2025-08-23 04:17:59	2460910.6791454	20.74	0.1		ABMag	g-Sloan	LT_IO-O	120	F. D. Romanov

Clear-

Other_Other

2025-08-17 15:00:24 - 2025-08-17 15:00:24

2460905.1252778 - 2460905.1252778

Photometry

ID	Obs-date	JD	Mag. / Flux	Err	Lim. Mag./Flux	Units	Filter	Tel / Inst	Exp-time	Observer/s	Remarks
510175	2025-08-17 15:00:24	2460905.1252778	19.6	0.3		VegaMag	Clear-	Other_Other	300	F. D. Romanov

AT Reports

Time received (UT)

Sender

Reporter/s

Reporting group

Disc. Data Source

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

267781

2025-08-26 23:03:40

Filipp Romanov

Filipp Romanov et al.

F. D. Romanov

00:48:18.875

+07:59:00.67

2025-08-23 04:17:58.560

20.74

g-Sloan

PSN

SDSS J004819.14+075856.8

PSN J00481888+0759006

F. D. Romanov

Follow-up photometric observations of AT 2025umq = PSN J00481888+0759006 using the Liverpool Telescope.

Related files

File	Comments	Last Modified (UT)	Modified By
tns_2025umq_atrep_267781_F._D._Romanov.jpg	Stacked (3x60 sec. images with g', r' and i' filters from the Liverpool Telescope; 0.30"/px, north is up, east is left) color image of AT 2025umq for 2025-08-24 03:53:55 UT.	2025-08-26 23:03:41	Filipp Romanov

266598

2025-08-19 16:02:01

Filipp Romanov

Filipp Romanov et al.

F. D. Romanov

00:48:18.875

+07:59:00.67

2025-08-19 03:49:12.000

20.3

r-Sloan

PSN

SDSS J004819.14+075856.8

AT 2025umq

F. D. Romanov

Follow-up observation of AT 2025umq using the Liverpool Telescope

Related files

File	Comments	Last Modified (UT)	Modified By
tns_2025umq_atrep_266598_F._D._Romanov.jpg	Stacked image from the Liverpool Telescope	2025-08-19 16:02:02	Filipp Romanov

266553

2025-08-18 21:51:52

Filipp Romanov

Filipp Romanov et al.

F. D. Romanov

00:48:18.884

+07:59:00.56

2025-08-17 15:00:24.000

19.6

Clear-

PSN

SDSS J004819.14+075856.8

Romanov SN2

F. D. Romanov

Possible supernova discovered at iTelescope.Net T59 (0.51-m f/6.8 reflector + CCD) at Siding Spring Observatory, Australia, visible in 5 images with exposures of 300 seconds.

2025TNSTR3252....1R

Related files

File	Comments	Last Modified (UT)	Modified By
tns_2025umq_atrep_266553_F._D._Romanov.jpg	Stacked 5x300 sec. image from iTelescope.Net T59 (0.51-m f/6.8 reflector + CCD).	2025-08-18 21:51:52	Filipp Romanov

Classification Reports

Time received (UT)

Sender

Classifier/s

Group

Classification

Redshift

Spectra

Related files

Assoc. Groups

End prop. period

Remarks

ADS Bibcode

21875

2025-08-27 01:11:13

Filipp Romanov

Filipp Romanov (amateur astronomer, member of the AAVSO), Jacob Wise (LJMU), Christoffer Fremling (Caltech)

F. D. Romanov

SN Ia

0.159

F. D. Romanov

The spectrum of AT 2025umq (PSN J00481888+0759006) was obtained during 3400 seconds (PATAG proposal AZ22A01; PI: F. Romanov) on 2025-08-20, midtime 03:06:46 UT, remotely using the low resolution (approximately R = 350 = 18 Å) SPRAT (Piascik et al. 2014) spectrograph on the Liverpool Telescope with the red-optimised mode (grating option). The same image shows spectra of both the SN candidate and SDSS J004819.14+075856.8: the host galaxy spectrum shows H-alpha emission, and also sodium (Na D) absorption features, this allowed to narrow down the redshift to z = 0.159. Comparison (using the software package "Next Generation SuperFit" (NGSF): Goldwasser et al. 2022) of the spectrum of AT 2025umq to templates of previously classified transients at a redshift of z = 0.159, finding it to be consistent with a fading Type Ia supernova: the typical feature caused by high velocity iron is visible between approximately 5000 Å and 5500 Å; and silicon absorption feature is visible at approximately 7100 Å. ZTF light curve (presented online https://alerce.online/object/ZTF25abexekl , but the photometric data were not reported to the TNS) shows the first g-band detection on 2025-07-25 and the peak magnitude of about +20 near August 10, 2025. Calculation with K-correction shows the absolute magnitude of about -19.6, this also corresponds to a Type Ia supernova. Based on the above, we classify AT 2025umq as Ia supernova in the galaxy SDSS J004819.14+075856.8.

2025TNSCR3400....1R

Related files

File	Comments	Last Modified (UT)	Modified By
tns_2025umq_atrep_21875_F._D._Romanov.png	The spectrum of the host galaxy SDSS J004819.14+075856.8	2025-08-27 01:11:13	Filipp Romanov
tns_2025umq_atrep_21875_F._D._Romanov_0.png	The spectrum of the supernova SN 2025umq	2025-08-27 01:11:13	Filipp Romanov
tns_2025umq_atrep_21875_F._D._Romanov.pdf	Supernova template fitting using the software package "Next Generation SuperFit" (NGSF): Goldwasser et al. (2022)	2025-08-27 01:11:13	Filipp Romanov

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
21875	2025-08-20 03:06:46	LT / SPRAT	3400	F. D. Romanov		F. D. Romanov	tns_AT_2025umq_2025-08-20_03-06-46_LT_SPRAT_F._D._Romanov.txt	tns_AT_2025umq_2025-08-20_03-06-46_LT_SPRAT_F._D._Romanov.fit	Object

Comments

ATel #17361

More information about the supernova SN 2025umq is available in the ATel #17361 https://www.astronomerstelegram.org/?read=17361

Object coordinates updated

Object coordinates updated according to AT-report 266598 of Group F. D. Romanov
Previous RA, DEC: 00:48:18.884, +07:59:00.56 (12.078683, +7.983489)
Updated RA, DEC: 00:48:18.875, +07:59:00.67 (12.078646, +7.983519)