Spectroscopic observations of Nova Sge 2026 (PNV J19450648+1822422)
ATel #18014; Gesesew Reta Habtie (Debre Berhan University)
on 27 Aug 2026; 16:02 UT
Credential Certification: Gesesew Reta Habtie (gesesew@bose.res.in)
Subjects: Optical, Cataclysmic Variable, Nova
I report optical spectroscopic observations of the newly discovered nova
Nova Sge 2026 (ATel #18009), located at
RA (J2000) = 19h 45m 06.48s,
Dec (J2000) = +18° 22′ 42.2″.
Spectra were obtained on 2026 August 25 at 20:26:32 UT
and 2026 August 27 at 04:05:40 UT from the
Three Hills Observatory (THO), United Kingdom, and
Oak Observatory, United States, respectively.
The observations were obtained by Robin Leadbeater
and Keith Shank, respectively.
Gaussian-profile fitting of the Hβ and Hα regions was performed
to characterize the emission and P-Cygni absorption components of the
first spectrum. The Hβ emission component is centered at
4862.69 Å, corresponding to approximately
+84 km s−1, with an intrinsic FWHM of
1122 km s−1. Its blueshifted P-Cygni
absorption component is centered at 4837.88 Å
(−1446 km s−1) with an intrinsic
FWHM of 700 km s−1. Similarly, the
Hα emission component is centered at 6567.00 Å
(+192 km s−1) with an intrinsic FWHM of
1296 km s−1, while the associated
absorption component is centered at 6528.38 Å
(−1572 km s−1) with an intrinsic
FWHM of 854 km s−1. The blueshifted
absorption components indicate high-velocity outflows, with characteristic
velocities of approximately 1500 km s−1.
The broad Balmer emission profiles are consistent with rapidly expanding
nova ejecta.
The second spectrum exhibits prominent Fe II emission features, including
Fe II λ4924, λ5018, λ5169, and λ5276, strongly
supporting the classification of Nova Sge 2026 as an
Fe II-type nova. Compared with the first spectrum, the
Hα and Hβ emission lines show a substantial increase in their
intrinsic FWHM, reaching approximately 3316 km s−1
and 3110 km s−1, respectively. At the
same time, the previously prominent P-Cygni absorption components have
almost completely disappeared, indicating a rapid evolution of the
line-forming regions and a transition toward more optically thin ejecta.
The broad Balmer emission profiles indicate high-velocity expanding
material, while the rapid weakening of the P-Cygni absorption suggests
significant changes in the ionization and optical-depth conditions of
the ejecta. These spectroscopic characteristics are consistent with a
rapidly evolving nova eruption.
Acknowledgements: I acknowledge
Robin Leadbeater and Keith Shank for
the observations and Francois Teyssier for
coordinating the ARAS spectroscopic database.
