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Nova M31

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Daryl's picture
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Nova M31
nickjames's picture
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Pre-discovery

Here it is on my patrol image from early evening on Oct 26. M31 novae are very frequent and discovering them is very competitive. This image also shows AT 2020vak much closer to the core.  

Robin Leadbeater's picture
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AT 2020vak

Hi Nick,

Has 2020vak been positively identified as an M31 nova?  I am not saying it isn't but it wasn't clear from  the amateur spectrum posted on TNS

https://wis-tns.weizmann.ac.il/object/2020vak

Cheers

Robin

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Nova?

You're right. I tend to be very lax and use the term nova for anything that varies in M31. Transient would be a much better term to use. That spectrum doesn't look very nova like. It is very close to the core though so how do you stop the spectrum being polluted by the background?

Robin Leadbeater's picture
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2020vak classification

Yes this one is against a bright background. This can be subtracted out using regions above and below the target in the slit but it does depend on this being uniform (both in brightness and spectroscopically) so you have to watch for galactic features. 

The last time I checked the ATels  this group were suggesting the spectrum resembles that of an F star. This rather rang alarm bells with me though as that is that is what might be expected from the integrated light from the galaxy. I see now here though it has been classified as an Fe II nova. What brightness would you estimate?  (Not that I am going to be observing any time soon from the forecast. As I am writing this the hailstones are hammering on the window)  

Robin Leadbeater's picture
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some example spectra

These are some I have managed to tease out in the past (full scale in the attachment)

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nickjames's picture
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It is difficult to get a

It is difficult to get a reliable magnitude but 2020 vak was around 16.6 (unfiltered vs Gaia DR2 G) on my image of Oct 26.8.

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M31N 2008-12a

Just a reminder: M31N 2008-12a is due to go off any day now.  This recurrent nova goes into outburst at roughly 11-monthly intervals and reaches mag 18 or so at maximum. It is visible for only a few days each time and nightly monitoring of the field is recommended.

https://arxiv.org/pdf/1607.08082.pdf contains a finder chart and magnitudes in a number of photometric bands for a number of comparisons.

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This is in one of my lesser

This is in one of my lesser patrolled fields around M31 (my field 15). I try to get a deep image of the core of M31 every available night but I'll keep an eye on this field too. Nothing there at the moment.

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Hi All

Hi All

I just opened this thread about the new outburst of M31N 2008-12a:

https://britastro.org/node/24796

Ciao,

Ernesto