Z CamPaign Targets for 2014
Mike Simonsen
In the Z CamPaign Update for December 2013, I told you where we stand with results from the first four years, new findings and publications, and I hinted at where we might go from here. Without further ado, here is a list of Z CamPaign targets for 2014, with some notes on individual stars and priorities.
First, please continue to monitor as many of the bona fide Z Cam stars as possible every clear night at least once per night in V. Time series are not required at this stage of the project.
Of the list of known Z Cams, there are still several that need denser coverage than they have been getting in the past to fill out the light curves and reveal these stars secrets and true nature. Observations of AY Psc, HL CMa, BX Pup, Leo5, ST Cha, HP Nor, UZ Ser, BP CrA are particularly valuable in this regard.
Below is the list of bona fide Z Cam stars.
*Asterisks denote stars that have been shown to go into outburst from standstill.
There may be more. Please continue monitoring for such activity.
The list of suspected Z Cams has grown slightly with the addition of two new stars, 1RXS J015017.0+375614 and CSS 100624:220031+033431
1RXS J015017.0+375614 does appear to be in standstill in the CRTS light curve. I would jump on this star right away and stick with it for the next year. It could remain in standstill, go into outburst or fade to quiescence at any time, and we don’t want to miss it. If we can establish that this is currently a standstill, and then show “normal” dwarf novae behavior for a month or more, we can include this one as a new bona fide member and publish another result.
Light curve of 1RXS J015017.0+375614 showing what appears to be a standstill
(Drake et al. 2009, ApJ, 696, 870)
With another solid year or two of nightly data we should be able to establish whether or not V392 Per, PY Per, WZ CMa, V426 Oph, V868 Cyg, IS Del and TT Ind are Z Cams or not. These are the brighter, well observed stars on the suspect list, so let’s prioritize these for 2014 and see if we can’t catch them in the act of a standstill.
I think we can drop V735 Sgr and V991 Aql from the list of suspects with a little more literature research, so don’t waste any open shutter time on these stars unless you hear otherwise from me.
The remaining stars on the list are generally fainter and will require some serious effort, and larger apertures to unlock their secrets. The full list of suspects for 2014 is below.
Finally, there are some stars who are not Z Cams but are interesting enough to follow in their own right that I am going to mention them here, hoping some of you will adopt one or more to your program.
There has been a lot written about FS Aur, and I think the book is still open on this one. It may not be relevant to the Z CamPaign, but observations of this star will be of interest to astronomers for a long time to come.
V849 Her and FY Vul are nova-like variables that are active enough to be interesting to follow, and may eventually become the subjects of the next phase of the Z CamPaign – investigating the continuum of dwarf novae behavior, the evolution of DNe from one class to another and the relationship to the hibernating novae theory.
And finally, V1363 Cygni is a fascinating, as yet unclassified oddball in the CV zoo. Denser CCD coverage exposing the behavior of this star at faint magnitudes below outburst (where is spends most of its time) reveal a restless unpredictable nature.