[vsnet-alert 11418] re V2672 Oph rebrightening - dig out the V and Rc filters

[rtrans at mail.org]

Berto Monard alerted and advised :-

"V2672 Oph, the fast nova in Oph was quite steady last night but suddenly 
started to rebrighten from JD 5065.321 onwards at a rate of 0.36 mag/hour as 
observed with an unfiltered CCD.  I am pleased to have registered the sudden change in the light curve and 
look forward to what's happening next.

Please join me in observing this interesting object,"

Very nice, and very interesting.

I take it unfiltered here means a red sensitive CCD chip?

If so then we have something that I believe happened with the last RS Oph outburst, and likey other past ones.  After a few days red passbands showed a brightness rise before returning to shallow decline whilst V remained more or less the same sort of shallowing decline as Halpha emission seriously kicked in, affecting the red area and leaving the V area untouched, sort of thing.

So people should aim towards doing V and Rc in tandem where capable, and the spectroscopists might want to try some time series.

I'm not overly sure on this, I'm just giving it a quick heads up to the photometrists whilst the time zones spin round and the egg spurts get online.  Putting filters on it won't hurt anyway, but looks like some Rc is in order, either mixed with V or just Rc on it's own for those with that capacity as I suppose more folk will be capable of doing the V for comparison than have access to Rc.

But it's potentially a congrats to Berto for giving some prompt and early likely confirmation of a recurrent nova like nature, possibly NRA? (red giant NR like T CrB and RS Oph), for this object.

John Greaves

PS there does seem to be a relatively easy optical progenitor for this object, both in images (likely it's even at different mags in 1950 and 1985 red plates), supercosmos Halpha catalogue/images for 1999, and in DENIS catalogue as well as in 2MASS images (albeit not catalogued), despite some comments that there ain't.  A bit confusing in general, but it's unclear what the situation is re this thing.  Unfortunately it's not in UKIDSS dr3, any ESO member with access to UKIDSS dr5 might think to look in images/catalogues of that, as that'd certainly clarify the progenitor situation if it's in there due to the higher resolution images.


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