Evolution of the dusty nova QY Mus from eruption to quiescence
Year: 2026
Type: article
Abstract: ABSTRACT We present a comprehensive study of the spectrophotometric evolution of the classical nova QY Mus from eruption to quiescence. The light curve shows a notable dust dip, classifying it as a D (137)-type nova, with dust formation beginning at $\sim$123 d post-outburst and reaching a maximum optical depth of $\tau \sim 3.2$. We classify QY Mus as a slow nova with $t_2 = 87 \pm 6$ d, and derive an absolute magnitude of $M_V = -6.55 \pm 0.54$ using the magnitude versus rate of decline relation. The spectroscopic evolution, traced from 94 to 1348 d, shows prominent P-Cygni profiles in Balmer and Fe ii lines during the early decline, consistent with an Fe ii-type nova. The transition to the nebular phase occurs around $\sim$233 d, marked by the emergence of [O iii] emission. Photoionization modelling using cloudy of 41 emission lines on day 590 yields a central source temperature of $(7.08 \pm 0.20)\times 10^{5}$ K, with enhanced nitrogen and oxygen abundances and moderate neon enrichment, suggesting that QY Mus is not a neon nova. Mid-infrared WISE observations at $\sim$502 d indicate the presence of cool dust at $\sim$400 K. Using a Gaia-based colour–magnitude diagram constructed in this work for 34 quiescent novae, we find that QY Mus occupies a region consistent with systems hosting main-sequence or subgiant secondaries; its orbital period further supports a subgiant companion. These results establish QY Mus as a slow, dust-forming nova with well-characterized evolution and a subgiant secondary.
Institutions: Indian Centre for Space Physics, Stony Brook University
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $3,046
OpenAlex ID: W7162859942