Spectroscopic and geometrical evolution of the ejecta of the classical nova ASASSN-18fv

Abstract

The optical spectroscopic observations of ASASSN-18fv observed from 2018 March 24 to 2019 January 26 are presented. The optical spectra are obtained from Mirranook, Vainu Bappu, and South African Astronomical observatories. The spectra are dominated by the hydrogen Balmer, Fe ii, and O i lines with P-Cygni profiles in the early phase, typical of an Fe ii class nova. The spectra show He i lines along with H i and O i emission lines in the decline phase placing the nova in the hybrid class of novae. The spectra show rapid development in high-ionization lines in this phase. Analysis of the light curve indicates t2 and t3 values of about 50 and 70 d, respectively, placing the nova in the category of moderately fast nova. The ejectum geometry, inclination, and position angle are estimated using morpho-kinematic analysis. The geometry of the ejecta is found to be an asymmetric bipolar structure with an inclination angle of about 53○. The ejected mass using photoionization analysis is found to be 6.07 × 10−4 M⊙.

Two new nova shells associated with V4362 Sagittarii and DO Aquilae

“…Although there had been previous discussions on how a nova shell's morphology could be derived from observed emission line structure, with early work summarised in Payne-Gaposchkin (1957). The effort has been continued in more recent years in Ribeiro et al (2009), Ribeiro et al (2011), Ribeiro et al (2013b), Munari et al (2010), Ribeiro et al (2013a), Harvey et al (2016), Harvey et al (2018) and Pavana et al (2020).…”

The onset of jets in classical novae

“…The optical AAVSO light curve shows some initial flares up to around +30 d, and exhibited weak cusp-like behaviour between +100 d and +150 d. used correlated flares in the optical and gamma-ray light curves of V906 Car to show that the emission in both bands is probably powered by the same underlying mechanism, which they took to be fast outflow colliding with slower outflows, and shock-heating it. Observations by Pavana et al (2020) show V906 Car to be of the hybrid class of classical novae. Wee et al (2020) associate V906 Car with the Carina Nebula, and thus assume a distance to the classical nova of = 2.3 ± 0.5 kpc.…”

“…[a] Banerjee et al (2015);[b] Pavana et al (2020);[c] A.Carr et al (2020);[d] Aydi et al (2020b);[e] McLoughlin et al (2021); [f] Sokolovsky et al (2020a); [g] Gehrz et al (2018); [h] Sokolovsky et al (2020b); [i] L. Izzo et al (2020);[j] Wee et al (2020…”

The onset of jets in classical novae

“…The optical AAVSO light curve shows some initial flares up to around +30 d, and exhibited weak cusp-like behaviour between +100 d and +150 d. used correlated flares in the optical and gamma-ray light curves of V906 Car to show that the emission in both bands is probably powered by the same underlying mechanism, which they took to be fast outflow colliding with slower outflows, and shock-heating it. Observations by Pavana et al (2020) show V906 Car to be of the hybrid class of classical novae. Wee et al (2020) associate V906 Car with the Carina Nebula, and thus assume a distance to the classical nova of 𝑑 = 2.3 ± 0.5 kpc.…”

“…[a] Banerjee et al (2015);[b] Pavana et al (2020);[c] A Carr et al (2020)Aydi et al (2020b);[e] McLoughlin et al (2021); [f] Sokolovsky et al (2020a); [g] Gehrz et al (2018); [h] Sokolovsky et al (2020b); [i] L. Izzo et al (2020);[j] Wee et al (2020…”