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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.
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.
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
Gary
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 ± 0.11
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).
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?
Good to see your photometry run, Maxim. Thank you!
My first reaction, like yours, is it’s probably flickering. But time will tell
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.
It appears that the slightly overdue outburst of CG Dra has finally started…
June 16.895 UT 15.87CV (SLOOH)
Gary
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)
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. Stewart
Using iTEL 18 (Spain), Vphot gave a V filter mag of 16.86 ( three 300s images stacked) this morning. Stewart
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 2459400.480961
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.
Gary
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.
Stewart
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.
Stewart
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