A team of astronomers has conducted an extensive study on LMCN 2009-05a, a nova located in the Large Magellanic Cloud (LMC). Originally reported in May 2009, LMCN 2009-05a has attracted considerable interest because of its unusually high rate of dust production and unusual ‘double-shell’ structure. This nova is confirmed as a classical moderately fast nova. It has a great expansion velocity too – about 690 kilometers per second!
LMCN 2009-05a had an absolute magnitude of -6.65 and a peak outburst luminosity of 46,400 L⊙. Our study confirmed that the nova is visible in all four WISE bands. These bands are W1 at 3.4 µm, W2 at 4.6 µm, W3 at 12 µm, and W4 at 22 µm. Emissions from the W2 and W3 bands were pronounced, pointing to processes at work within the nova.
Led by Mohit Singh Bisht, this research team made a promising finding. They noticed that the dust formation in ejecta became very prominent in the optical and near-infrared light curves of LMCN 2009-05a between 78 and 155 days post-outburst. On day 395 following the outburst we measured a dust temperature of ~700 K. This finding indicates that thermal dynamics are still very much at play inside the nova.
Spectrophotometric evolution indicates that LMCN 2009-05a is a classical moderately fast nova. This nova is unique for its extreme dust formation as well as ionization structure evolution. It matches well to known D-class light curve morphology,” Bisht and his coauthors wrote.
The spectra of LMCN 2009-05a exhibit prominent hydrogen Balmer and iron lines. These lines show P-Cygni profiles, showing the existence of expanding gas in novae. We estimate the progenitor white dwarf of LMCN 2009-05a to be 0.77±0.10 M⊙. This low mass not only makes it sub-luminous, but it puts it in a unique category of novae.
This study deepens our understanding of LMCN 2009-05a. Beyond its specific legacy, it contributes to our general understanding of nova phenomena, laying the groundwork for ongoing and future research. Astronomers study how dust forms and how ionization evolves. Their ultimate aim is to understand the intricate physical processes involved in producing these spectacular astronomical phenomena.