Home › Forums › Variable Stars › CG Dra: a VSS campaign
- This topic has 191 replies, 9 voices, and was last updated 1 month, 2 weeks ago by Maxim Usatov.
9 May 2021 at 8:02 pm #574963
I’ve just posted an article about observing this dwarf nova. This is a star that is always doing something. It has outbursts every 11 days or so, and yet has been neglected of late.
It’s also a good target for those wanting to have a go at digital photometry. For several years I used a 10 cm refactor and CCD to follow this object. And you don’t need to use a filter. Perhaps you can fit in a few 60 sec exposures among your other imaging projects.
Visual obs also welcome, although at it’s brightest it’s 15th mag, so a large telescope will be needed.11 May 2021 at 9:40 am #584196
Many thanks for the article, Jeremy. I’ve scheduled a few instruments in Spain and New Mexico, so hopefully will have some data to chew on.11 May 2021 at 12:47 pm #584198
That’s super, Maxim. Good luck!14 May 2021 at 11:21 am #584202
CG Dra has been slowly rising to outburst over the past couple of nights…
May 10.06UT 17.06CV
May 12.01UT 16.88CV
May 12.98UT 16.15CV
May 13.95UT 15.90CV
Uisng both the OU COAST and SLOOH 2
Gary16 May 2021 at 9:18 am #584211
Alas, poor weather at my all locations. Runs cancelled one after another. Was only able to get this today on 0.5 m in New Mexico:
CG Dra, 2021-05-16 07:04:57.000 UTC, V = 16.33 ± 0.1117 May 2021 at 4:19 pm #584228Graeme CoatesParticipant
Looks like it’s on the fade after the peak on the 13th/14th – back at about 16.7CV early this morning (17-May-21 03:18-03:56UT).18 May 2021 at 3:36 pm #584235
Got a good session on May 17th. First observation 06:02, last 09:04 UTC. I wonder, is this a ~ 0.2 mag flickering or irregular modulations or this is actually an eclipse? In case of the latter then why the exit follows by an irregular tail – clumpy accretion disk?18 May 2021 at 6:40 pm #584236
Good to see your photometry run, Maxim. Thank you!
My first reaction, like yours, is it’s probably flickering. But time will tell22 May 2021 at 9:37 am #584250
16.9 V mag on the early morning 20th May. Data is at AAVSO site. Stewart28 May 2021 at 1:24 pm #584271
A few more observations – moonlit sky.29 May 2021 at 11:33 am #584274
CG Dra, 2021-05-29 09:17:01.000 UTC, V = 16.71 ± 0.091
Difficult to get any good accuracy due to the Moon now.17 June 2021 at 2:21 pm #584375
It appears that the slightly overdue outburst of CG Dra has finally started…
June 16.895 UT 15.87CV (SLOOH)
Gary23 June 2021 at 10:14 am #584385Graeme CoatesParticipant
Looks like this is a “long” type outburst – appeared to be still brighter than mag 16 this morning from Spain:
Jun 23.131UT 15.84CV (+/-0.04)26 June 2021 at 11:54 am #584394
Ken Menzies (AAVSO) has helped me upload images with the clear filter as CV into the AAVSO database. All fit with the existing results from other observers so I seem to have done it right. Stewart2 July 2021 at 1:57 pm #584410
Using iTEL 18 (Spain), Vphot gave a V filter mag of 16.86 ( three 300s images stacked) this morning. Stewart6 July 2021 at 1:45 pm #584418Dr Paul LeylandParticipant
My first scientific observation since returning to La Palma and to a whole host of instrumental and computer problems.
V=16.85 ± 0.04 at JD 2459400.4809617 July 2021 at 3:49 pm #584429
CG Dra currently in outburst …
Jly 04.909 16.77CV; Jly 05.951 15.98CV; Jly 06.695 15.89CV
About 20d since previous (long) outburst.
Gary10 July 2021 at 4:32 pm #584440
iTEL 18 and Vphot report CG Dra, 2459405.55119, 16.693 V filter
So a short outburst that I have just missed. Still all results are useful. iTEL subscription get refreshed on the 12th so will try again.
Stewart19 July 2021 at 3:53 pm #584486
iTEL 18 and Vphot gave CG Dra at 16.71 very early this morning.
Check star 147 (14.674 ) estimated at 14.679. Airmass 1.04.
Stewart19 July 2021 at 10:55 pm #584488Nick JamesParticipant
Yes, it looks to be at the bottom of a cycle.
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