A recurrent nova super-remnant in the Andromeda galaxy

Area of Science:

• Astronomy and Astrophysics
• Stellar Evolution
• Galactic Dynamics

Background:

• Classical novae result from hydrogen accretion onto white dwarfs, causing thermonuclear runaways and mass ejection.
• Recurrent novae, occurring on shorter timescales, are white dwarf binary systems with rapid accretion rates.
• Ejecta from novae sweep up interstellar medium, forming cavities, but large remnants from single eruptions are unknown.

Purpose of the Study:

• To investigate the presence and scale of remnants from recurrent nova eruptions.
• To determine if frequent, successive eruptions can generate large-scale structures.
• To analyze the nova M31N 2008-12a, known for its annual eruptions.

Main Methods:

• Observational astronomy utilizing imaging and spectroscopic data.
• Analysis of the spatial extent and morphology of ejecta surrounding M31N 2008-12a.
• Comparison of the observed remnant size with theoretical models and known supernova remnants.

Main Results:

• Discovery of a large super-remnant surrounding the recurrent nova M31N 2008-12a.
• The remnant has a projected size of at least 134 by 90 parsecs.
• This structure is significantly larger than remnants from single nova eruptions and most supernova remnants.

Conclusions:

• The existence of this super-remnant confirms M31N 2008-12a has erupted frequently for millions of years.
• Recurrent novae can generate vast shells over long timescales, shaping the interstellar medium.
• This finding highlights the significant cumulative impact of recurrent novae on their galactic environment.