Is Photometry of Cataclysmic Varible after Outburst Useful?
Announcement: New Forums
We are excited to announce the launch of our new forums! You can access it forums.aavso.org. For questions, please see our blog post. The forums at aavso.org/forum have become read-only.
American Association of Variable Star Observers (AAVSO)
Fri, 06/20/2014 - 21:21
Hello! I imaged a couple of nova last year. As they start to rise in my location, I'm wondering if it would be helpful to provide images/data now that they are not in outburst? Thank you and best regards.
As Brian say, absolutely. In particular, time-series observations becoming very interesting once the nova ejecta have become optically thin in its "nebular" phase. The stuff on the surface of the white dwarf has been blasted out far enough that it is cool and at a very low density, allowing us to see back into the binary system itself (during the explosion, it's essentially a giant opaque fireball). So time series once the fireball has faded allow us to look at what's happening in the binary system itself: eclipses (if the inclination is right), reformation of the accretion disc, flickering and others.
Right now V5666 Sgr (Nova Sgr 2014) has plateaued around V Mag 12.7, and seems to be showing quasi-periodic oscillations of 0.03-0.05 Mag with a period around 10-15 mins. Our old friend V339 Del seems to be doing something very similar (Mag c.12.5, oscillations of c.17 mins) but that's based on only one timeseries on June 7 by CMJA. V1369 Cen is six months after maximum, but still at V mag 8, and has been full of surprises. I'm sure there's more of interest to come in this system.
Going beyond the classical novae, few months ago there was also a call on these forums for time-series on recurrent nova V745 Sco, but at fainter than Mag 18 this one is beyond my aperture; I'd need 30 mins integration to get a decent SNR for a single measurement.
My favourite of all is PNV J17144255-2943481, a newly-discovered WZ Sge-type dwarf nova. It hit its maximum of V 10 on April 12. It's faded to 15.5 now, superhumping on the way down, but was regularly (?) rebrightening to 13 every 4 days or so. It's a fascinating light curve to have a look at, but only one regular oberver, HMB. If it ever clears here I'll get some data on this one, using no filter and V zero point.
All these except V339 Del are Southern objects, of course. I daresay the Northern objects on Arne's list are equally interesting.
Absolutely! Take a
Hi Mike,
Absolutely! Take a look at Arne's recent post on continuing to follow recent novae: http://www.aavso.org/nova-updates
Regards,
Brian
As Brian say,
Hi Mike,
As Brian say, absolutely. In particular, time-series observations becoming very interesting once the nova ejecta have become optically thin in its "nebular" phase. The stuff on the surface of the white dwarf has been blasted out far enough that it is cool and at a very low density, allowing us to see back into the binary system itself (during the explosion, it's essentially a giant opaque fireball). So time series once the fireball has faded allow us to look at what's happening in the binary system itself: eclipses (if the inclination is right), reformation of the accretion disc, flickering and others.
Right now V5666 Sgr (Nova Sgr 2014) has plateaued around V Mag 12.7, and seems to be showing quasi-periodic oscillations of 0.03-0.05 Mag with a period around 10-15 mins. Our old friend V339 Del seems to be doing something very similar (Mag c.12.5, oscillations of c.17 mins) but that's based on only one timeseries on June 7 by CMJA. V1369 Cen is six months after maximum, but still at V mag 8, and has been full of surprises. I'm sure there's more of interest to come in this system.
Going beyond the classical novae, few months ago there was also a call on these forums for time-series on recurrent nova V745 Sco, but at fainter than Mag 18 this one is beyond my aperture; I'd need 30 mins integration to get a decent SNR for a single measurement.
My favourite of all is PNV J17144255-2943481, a newly-discovered WZ Sge-type dwarf nova. It hit its maximum of V 10 on April 12. It's faded to 15.5 now, superhumping on the way down, but was regularly (?) rebrightening to 13 every 4 days or so. It's a fascinating light curve to have a look at, but only one regular oberver, HMB. If it ever clears here I'll get some data on this one, using no filter and V zero point.
All these except V339 Del are Southern objects, of course. I daresay the Northern objects on Arne's list are equally interesting.
Cheers
Jonathan
Johnathen,
When you write "Arne's list" in the last paragraph of your post, to what list do you refer and where is it available?
PS. never mind I found it in the previous post.
Thanks.