[vsnet-alert 10662] Re: [AAVSO-DIS] (fwd) V838 Mon: Radical spectral changes at short wavelengths

[arne]

Sebastian Otero wrote:
>> To understand these changes, one should take into account that before 
>> the explosion in 2002, V838 Mon was a system containing two B3V type 
>> stars, and the brighter companion exploded. The remnant of the 
>> explosion was an expanding very cool star, a possible L type 
>> supergiant. 
> 
> . why should a B3V dwarf explode?
> 
(I think I am subscribed to all of these lists, but will restrict any
further responses to aavso-discussion only)
Sebastian's question is at the crux of the matter: what really happened
in this outburst, and do we really know what the progenitor was?
Since the system continues to evolve, I think the final answer still
eludes us.  Let's just say that this is a unique, very interesting
system that deserves some attention for years to come.  Goranskij,
Bond, Munari and myself continue to monitor this system from different
sites - now nearly 7 years after the outburst!  "Monitor" means
an observation once a month or so; plenty of room for amateurs
to get involved.  Unfiltered time-series photometry might be interesting,
or if you have a large telescope, B-band time series would be even
more interesting.  Watch out for the close companions, though!

Many novae deserve more attention.  Usually there are lots of observers
monitoring the outburst, but once a nova fades, interest gets diverted
elsewhere.  Of the last 50 novae, most are still visible with amateur
telescopes.  We know little of the late-time behavior of these systems.
Arne