Artwork in GIMP of M31N 2008 12a
Well as I have posted, on December 31st, 2017, Recurrent Nova M31N 2008-12a erupted again for the 10th recorded time, though this recurrent Nova in the Andromeda Galaxy, M31, has probably been doing this for million of years. It is close, getting closer to either collapsing into a neutron star when it reaches the Chandrasekhar limit of 1.4 (1.44) solar masses if it is a Neon/Oxygen White dwarf, or into a Type Ia Supernova if the progenitor white dwarf is a Carbon/Oxygen White Dwarf. So far not spectra of Neon has been detected but we probably won't know until 20,000 years or so in the future when the event actually occurs. Okay, we won't know but our descendants will know.
The drawing above shows an exagerrated RN M31N 2008-12a as a bright reddish star on the left middle of the sketch. The rest of the sketch is my impression of the the extreme massive nova remnant that is brighter on the western side and arch and has filaments and other portions attached to it. This is based off of the XRay Data observation from the NASA Spitizer Space Telescope. Remember this is about as long as the Pleiades are from the Earth, thus a massive nova cloud.
Here you see again the large red dwarf companion and I have not included material moving on a accretion disc from the red dwarf companion, and instead have included a wind that is moving material off the red dwarf and that is accretting material onto the white dwarf star which you can see. This is causing a build up of material on the white dwarf that ends in either the confirmed annual eruption of late December each year, or a bi-annual eruption with the second eruption occurring in the spring when material has built up, resulting in an eruption that is blocked from being seen because of the position of Messier 31 and our Sun, which acts to block this event each year.
If you look at the material being blown off by the wind, using direct and averted vision I have tried to capture various layers of material being blown off and I think I have captured that nicely. I am fascinated by this object, and similar objects now in the Milky Way. I am working on a piece to share some of the closer and similar objects that are in our own Milky Way Galaxy. Truly our understanding of these complex systems is just beginning to emerge and the ground work being laid down here will impact future astronomers for a very long time!