Detection of ${}^7$Be II in the Classical Nova V5669 Sgr (Nova Sagittarii 2015 No.3)

Abstract

We report the new detection of ${}^7$Be II in the ultraviolet spectra of V5669 Sgr during its early decline phase ($+24$ and $+28$ d). We identified three blue-shifted absorption systems in our spectra. The first two, referred to as low- and high-velocity components, were noticeably identified among H I Balmer, Na I D, and Fe II whose lower energies of transients are low ($<4$ eV). The third absorption component was identified among N II, He I, and C II lines whose lower energy levels are relatively high (9--21 eV). The absorption lines of ${}^7$Be II at $3130.583$ Å, and $3132.228$ Å were identified as the first and second components in our observations. No evidence suggested the existence of Li I at 6708 Å in any velocity components. The estimated number density ratio of lithium relative to hydrogen, which was finally produced by this object using the equivalent widths of ${}^7$Be and Ca II K, $N({}^7\mathrm{Li})/N(\mathrm{H}{)}_{\mathrm{final}}$ is $4.0\pm 0.7\times 10^{-6}$. This value is an order of magnitude lower than the average observed values for classical novae wherein ${}^7$Be has been detected, and is comparable to the most optimistic value of theoretical predictions.

21 pages, 7 figures, accepted by ApJ

References in corpus (7)

• Modules for Experiments in Stellar Astrophysics (MESA)
• Explosive lithium production in the classical nova V339 Del (Nova Delphini 2013)
• Transient Heavy Element Absorption Systems in Novae: Episodic Mass Ejection from the Secondary Star
• Highly Enriched 7Be in the ejecta of Nova Sagittarii 2015 No. 2 (V5668 Sgr) and the Galactic Lithium origin
• 123-321 Models of Classical Novae
• A Light Curve Analysis of 32 Recent Galactic Novae --- Distances and White Dwarf Masses
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Cited by in corpus (7)

• 7Be detection in the 2021 outburst of RS Oph
• Novae: An Important Source of Lithium in the Galaxy
• Lithium evolution in the Galactic thin disc from Main-Sequence and early Red-Giant-Branch stars
• Unevolved Li-rich stars at low metallicity: a possible formation pathway through novae
• Gaia-Sausage-Enceladus: Lithium evolution from early red-giant-branch and main-sequence stars
• Viability of novae as sources of Galactic lithium
• 7Be in the outburst of the ONe nova V6595 Sgr