Liverpool Telescope spectroscopy identifies TCP J18251276-2225293 as an Fe II-type nova
ATel #17995; Jingyuan Zhao (Shandong Astronomical Society), Jiashuo Zhang (Walton International School), Ezhar Elijan (Wuhan University), Yaozhang Ou (Wuyi University)
on 20 Aug 2026; 22:16 UT
Credential Certification: Kirill Sokolovsky (kirx@scan.sai.msu.ru)
The NMW-TexasTech survey (Rokinon 135-mm f/2.2 telephoto lenses +
QHY600PH-M CMOS camera) discovered an optical transient of 9.4 mag
in Sagittarius on 2026 Aug 19.1063 UTC. They reported it to
the CBAT Transient Objects Confirmation Page, where it was
designated TCP J18251276-2225293 http://www.cbat.eps.harvard.edu/unconf/followups/J18251276-2225293.html
ATel #17987 reported follow-up astrometry and photometry suggesting
that it might be a Galactic nova. ATel #17989 reported
spectroscopic observations, confirming it as a classical nova.
As part of the PATAG proposal AL26A01, we obtained two epochs of
spectra for this transient using the SPRAT spectrograph (R~350;
Piascik et al. 2014) on the 2-m Liverpool Telescope
(Steele et al. 2004), on 2026 Aug 19.86471 and 19.94656 UTC.
The two spectra were stacked from 8x15 s and 5x30 s exposures,
respectively.
The two spectra are broadly similar, both showing clear Balmer
(H_alpha, H_beta, H_gamma) and O I 7773 emission lines with
prominent P Cygni profiles. In addition, features attributable to
Fe II (multiplets 42, 48, 49) and an absorption feature near Na I D
are present. We measure the FWHM of the H_alpha emission component
to be ~1300 km/s. Based on these spectral features, we classify
the transient as an Fe II-type nova (Williams 1992).
In the VISTA Variable in the Via Lactea Survey (VVV) DR4.2
(Minniti+ 2023), a source is found 0.285 arcseconds from
the reported position, with coordinates R.A. = 18 25 12.75,
Dec. = -22 25 29.5, and designation vvv J182512.75-222529.55.
On 2010 April 1.39235, its brightness in the J band was
18.62 +/-0.23 mag; on 2015 September 16.11035, its brightness in
the J band was 18.73 +/-0.24 mag (all photometry in the 1-arcsec
aperture). We consider it a possible host system of this nova.
Further observations are strongly encouraged.
Based on observations made with the Liverpool Telescope operated on
the island of La Palma by Liverpool John Moores University in
the Spanish Observatorio del Roque de los Muchachos of
the Instituto de Astrofisica de Canarias with financial support
from the UK Science and Technology Facilities Council.
Liverpool Telescope spectra of TCP J18251276-2225293
