American Association of Variable Star Observers (AAVSO)
Tue, 07/20/2021 - 18:46


AAVSO Alert Notice 747 announces an observing campaign on the WZ Sge-type cataclysmic variable V627 Peg. Please see the notice for details and observing instructions.

There are threads for this campaign under the following forums:

- Campaigns and Observation Reports:
- Cataclysmic Variables:
- Spectroscopy:

Please subscribe to these threads if you are participating in the campaign so you can be updated by the astronomer and by HQ. Join in the discussion or ask questions there!

Many thanks, and Good observing,

Elizabeth O. Waagen, AAVSO HQ

Vereniging Voor Sterrenkunde, Werkgroep Veranderlijke Sterren (Belgium) (VVS)
Current vis. magnitude 2021/07/20 21h35UT

Estimated current vis mag. 9.9 (9.5-10.2 comp. stars.).

Cassegrain 250mm, 90x.


American Association of Variable Star Observers (AAVSO)
Checking In

Hi all,

I'm Christian, the guy who requested your help with this target, so I just wanted to check in quickly to say hello and thank everybody who is able to contribute.

Hopefully the alert explains things well enough -- very briefly, this is kind of an exciting outburst, because V627 Peg is one of the closest WZ Sge-type dwarf novae, and -- like most of these systems -- erupts very infrequently, something like once every few years. Since the system is so nearby -- and therefore very bright in outburst -- this is a fantastic chance to follow the evolution of a WZ Sge outburst in more detail than is usually possible. In particular, high cadence photometry and even spectroscopy should be feasible even with relatively small apertures.

What we are especially interested in is the multi-wavelength evolution of the the system as it declines back into quiescence. We are currently getting X-ray and ultraviolet data with the Swift satellite observatory, and we have several radio telescopes trying to get observations that would allow us to track whether there is a jet in the system during outburst, and how this evolves. The sort of questions we'd like to answer are whether the (dis)appearance of the jet is connected to other events at other bands, e.g. the emergence of emission lines on the decline, or perhaps particular types of fast oscillations in the optical photometry, or maybe changes in the optical color of the system.

The Swift campaign will run for at least 30 days, so any data you can get over that period would be great. Spectroscopy and two-colour (B and V, say) high cadence photometry are especially encouraged for those of you who can do this. But any data will be useful in helping us to establish the optical evolution.

I'll try to check in here periodically to answer any questions that may arise, but please feel free to contact me directly as well if you need a response more quickly (