J/A+A/707/A326 Nova Vul 2024 (V615 Vul) spectra (Valisa+, 2026)
The hybrid Nova Vul 2024 (=V615 Vul).
Valisa P., Munari U., Albanese I.
<Astron. Astrophys. 707, A326 (2026)>
=2026A&A...707A.326V 2026A&A...707A.326V (SIMBAD/NED BibCode)
ADC_Keywords: Novae ; Spectra, optical
Keywords: novae - cataclysmic variables - stars: individual: V615 Vul
Abstract:
Among galactic novae, many remain poorly characterized due to
heterogeneous data, observational challenges, or heavy reddening along
the Galactic plane. A detailed characterization is particularly
crucial for novae exhibiting peculiar features, such as those
belonging to the hybrid class.
We present the spectroscopic and photometric evolution of the heavily
reddened Nova Vul 2024 (=V615 Vul) from discovery on 29 July 2024 to
well into its nebular phase.
We obtained daily optical, absolute-fluxed spectroscopy in both low-
and high-resolution echelle modes, providing a detailed account of the
spectral evolution. Photometric data were primarily sourced from the
AAVSO, while refined astrometry was performed to assess the positional
coincidence with a potential progenitor. Robust determinations of t3
and E(B-V) were achieved, allowing for the application of the Maximum
Magnitude-Rate of Decline (MMRD) relation; the resulting distance is
in excellent agreement with 3D Galactic extinction maps. Nova Vul 2024
is a very fast nova (t3=10.7±0.5 days) located at a distance of
5.0±1.0kpc, suffering from a large reddening E(B-V)=1.6±0.1.
Around maximum light, it exhibited a FeII-type spectrum with very
broad emission lines (FWZI=5800km/s) and high-velocity P-Cygni
absorptions. Following t3, coinciding with the emergence of hard X-ray
emission, the nova displayed pronounced photometric oscillations
driven primarily by continuum variations. Simultaneously, He/N
features developed alongside Fe II lines, classifying V615 Vul as a
rare hybrid nova. During the nebular phase, the ionization level
increased, reaching [FeVII] and likely [FeX]. The ejecta showed no
neon overabundance and expanded ballistically, as indicated by the
constant widths, profiles, and castellation of the high-resolution
emission lines.
Description:
The spectroscopic evolution is described using daily optical, absolute
flux-calibrated spectra obtained in both low-resolution and
high-resolution echelle modes at the Varese Schiaparelli Observatory
(0.84-m telescope) and at the Asiago Observatory (1.22-m and 1.82-m
telescopes).
Objects:
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RA (2000) DE Designation(s)
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19 43 07.51 +21 00 20.4 V615 Vul
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
list.dat 96 47 List of spectra
sp/* . 47 Individual spectra
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Byte-by-byte Description of file: list.dat
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Bytes Format Units Label Explanations
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1- 22 A22 --- FileName Name of the spectrum file in subdirectory sp
24- 96 A73 --- Title Title of the file
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Byte-by-byte Description of file: sp/*
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Bytes Format Units Label Explanations
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1- 16 F16.11 0.1nm lambda Wavelength in Å
18- 30 E13.7 10mW/m2/nm Flux Flux in erg/s/cm2/Å (1)
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Note (1): The spectra of Fig 5 and Fig 7 are flux calibrated.
The spectra of Fig 4 and Fig 8 are flux calibrated and corrected for reddening.
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Acknowledgements:
Paolo Valisa, paolo.valisa(at)astrogeo.va.it
(End) Paolo Valisa [Ans Collab., Asiago], Patricia Vannier [CDS] 19-Feb-2026