CG Dra: a VSS campaign

Forums Variable Stars CG Dra: a VSS campaign

Viewing 20 posts - 1 through 20 (of 196 total)
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  • #574963
    Jeremy Shears
    Participant

    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.

    #584196
    Maxim Usatov
    Participant

    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.

    #584198
    Jeremy Shears
    Participant

    That’s super, Maxim. Good luck!

    #584202
    Gary Poyner
    Participant

    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

    #584211
    Maxim Usatov
    Participant

    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

    #584228
    Graeme Coates
    Participant

    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).

    #584235
    Maxim Usatov
    Participant

    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?

    #584236
    Jeremy Shears
    Participant

    Good to see your photometry run, Maxim. Thank you!

    My first reaction, like yours, is it’s probably flickering. But time will tell

    #584250
    Stewart John Bean
    Participant

    16.9 V mag on the early morning 20th May. Data is at AAVSO site. Stewart

    #584271
    Maxim Usatov
    Participant

    A few more observations – moonlit sky.

    #584274
    Maxim Usatov
    Participant

    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.

    #584375
    Gary Poyner
    Participant

    It appears that the slightly overdue outburst of CG Dra has finally started…

    June 16.895 UT  15.87CV  (SLOOH)

    Gary

    #584385
    Graeme Coates
    Participant

    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)

    #584394
    Stewart John Bean
    Participant

    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

    #584410
    Stewart John Bean
    Participant

    Using iTEL 18 (Spain),  Vphot gave a V filter mag of 16.86 ( three 300s images stacked)  this morning. Stewart

    #584418
    Dr Paul Leyland
    Participant

    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

    #584429
    Gary Poyner
    Participant

    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

    #584440
    Stewart John Bean
    Participant

    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

    #584486
    Stewart John Bean
    Participant

    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

    #584488
    Nick James
    Participant

    Yes, it looks to be at the bottom of a cycle.

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