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AB DRA's Recent Behavior

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BRJ's picture
AB DRA's Recent Behavior

Has anyone else taken note of the rather abnormal behavior that 1953+77 AB DRA has been exhibiting in recent months? A check of its recent lightcurve shows infrequent and irregular outbursts relative to the previous 500-700 days. Earlier AB's outbursts came with much greater frequency and regularity. There is some suggestion that this CV undergoes intervals of odd irregularity, but this latest example seems more dramatic than those I've observed in the past.

J.Bortle   (BRJ)


lmk's picture
Possible UGZ?

Hi John, Yes, I had noted this new behavior too, in prior posts. Between Nov 2104 and Feb 2015, it appeared to have entered a "standstill", and since Mar 2015 has resumed outbursts from standstill, and has not returned to its original minimum area in the mag 15 range. However, I have been "overruled" by others in attempting to change its classification to such.



Lew Cook
Lew Cook's picture
VSX does have updated note

Mike and John, if you check VSX, it does have Mike's note. That is a good first step ...


spp's picture
possible UGZ?


I see that it had been previously classified as UGZ in Combined General Catalogue of Variable Stars (Vol. I-III) (Kholopov+ 1998).  When did it lose the Z?

I am now observing it in V and I, once per night, as frequently as weather permits.


BRJ's picture
AB DRA's Continuing Odd Behavior

I last posted regarding this variable's increasing odd behavior three months ago and since that time its state of inactivity has become even more excessive. It now appears that AB DRA has basically ceased to undergo outbursts all together, there not having been a confirmed normal outburst since the opening of September and even its possible but not well documented irregular fluctuation have died out recently.

A check of this star's long-term lightcurve going back 10,000 days indicates that no similar episode of inactivity has been reported previously and it is likely one can go back much further than this without finding such.

J.Bortle   (BRJ)

stellakafka's picture
change in quiescence!

Hello all,


I was looking at the full light curve and noticed that AB Dra was in a non-outbursting mode for about 3-4 months about the same time last year. Since then, the quiescence level has become brighter. This is not really a standshtill, but it is certainly a change in the behavior of the system. More data s needed!


CVs are fun!

Best wishes - clear skies,


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