RA/DEC (2000)
17:30:12.300 -27:53:48.80
262.55125 -27.896889
Type
Nova
Redshift
Discovery ReportClassification Report
Reporting Group
None
Discovering Data Source
None
Discovery Date
2025-09-05 10:22:36.000
TNS AT
Y
Public
Y
Discovery Mag
12.5
Filter
Clear-
Reporter/s
Tadashi Kojima
NEDSIMBADDECaLSPanSTARRS-1SkyMapperVizieRWISEDSSADS

Spectra

 ▌AT_2025wyg - 2025-09-05 17:19:40 Lesedi / Mookodi (BlackGEM)z=
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   Binning factor: (rounded to nearest integer >1)
Mouse hovers at WL: 0 (rest),

Light curves

 ▌Other_Other_Clear
   
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
21976 2025-09-05 17:19:40 Lesedi / Mookodi Moses Mlangeni BlackGEM tns_2025wyg_2025-09-05_17-19-40_Lesedi_Mookodi_BlackGEM.txt Object 2025-09-06 Lesedi/Mookodi spectrum (4200–8000 Å, R ≈ 350) obtained on 2025-09-05 shows strong Balmer emission with P-Cygni profiles (Hα absorption minimum at ~6515 Å → v ≈ 2200 km s⁻¹) and Fe II multiplet P-Cygni (λ4924) at redshift 0. The spectral features confirm AT 2025wyg as a Galactic Fe II classical nova.
Light Curves
Filter Tel / Inst Obs-date range JD Range Photometry
Clear- Other_Other 2025-08-30 11:04:12 - 2025-09-05 10:22:36 2460917.96125 - 2460923.9323611 2
Photometry
ID Obs-date JD Mag. / Flux Err Lim. Mag./Flux Units Filter Tel / Inst Exp-time Observer/s Remarks
515747 2025-09-05 10:22:36 2460923.9323611 12.5 13.2 VegaMag Clear- Other_Other 4 T.Kojima Canon EOS 6D digital camera + 300mm f/3.2 lens.
515746 2025-08-30 11:04:12 2460917.96125 13 VegaMag Clear- Other_Other 4 T.Kojima [Last non detection] Canon EOS 6D digital camera + 300mm f/3.2 lens.
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
269366 2025-09-05 13:04:31 Tadashi Kojima Tadashi Kojima et al. 17:30:12.300 -27:53:48.80 2025-09-05 10:22:36.000 12.5 Clear- PNV 2025TNSTR3574....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
21976 2025-09-06 11:40:59 Moses Mlangeni Moses Mlangeni (UCT/SAAO), Francois Campher (UCT/SAAO), Lloyd Lansburg (UCT/SAAO), Yusuke Tampo (SAAO), Paul Groot (UCT/SAAO/Radboud), Erez Zimmerman (Weizmann), Gavin Ramsay (Armagh) BlackGEM Nova 1 BlackGEM We obtained an optical spectrum of AT 2025wyg on 2025-09-05 17:19:40 UTC using the 1.0-m Lesedi telescope at the South African Astronomical Observatory equipped with the Mookodi spectrograph. The spectrum (4200–8000 Å; R ≈ 350) shows a blue continuum with strong Balmer emission, most prominently Hα, which exhibits a clear P-Cygni profile. The absorption minimum of Hα lies at ~6515 Å, corresponding to an expansion velocity of ~2200 km s⁻¹ relative to rest. Additional Fe II multiplet features (λ4924) also display P-Cygni structure. The presence of Balmer and Fe II P-Cygni profiles, with moderate expansion velocities, are characteristic of Fe II novae shortly after outburst. The absence of host galaxy features and the Galactic location of the source indicate that AT 2025wyg is a Galactic nova. We therefore classify AT 2025wyg as a classical nova of the Fe II spectroscopic type. 2025TNSCR3593....1M
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
21976 2025-09-05 17:19:40 Lesedi / Mookodi Moses Mlangeni BlackGEM tns_2025wyg_2025-09-05_17-19-40_Lesedi_Mookodi_BlackGEM.txt Object 2025-09-06 Lesedi/Mookodi spectrum (4200–8000 Å, R ≈ 350) obtained on 2025-09-05 shows strong Balmer emission with P-Cygni profiles (Hα absorption minimum at ~6515 Å → v ≈ 2200 km s⁻¹) and Fe II multiplet P-Cygni (λ4924) at redshift 0. The spectral features confirm AT 2025wyg as a Galactic Fe II classical nova.

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