Affiliation
Vereniging Voor Sterrenkunde, Werkgroep Veranderlijke Sterren (Belgium) (VVS)
Mon, 08/08/2016 - 15:34
Hi,
KT Per is acting very strange lately. It keeps hanging around 14.6 Could this be a standstill we are witnessing, although KT Per not catalogued as an UGZ...
Regards,
Eddy
It looks like its varying between mag 12 and 15 as normal, from the lightcurve? https://www.aavso.org/lcg/plot?auid=000-BBD-135&starname=KT%20PER&lastd…
Hi Mike,
Last night still not in quiescence. It keeps hanging around mid 14th magnitude. Have this been seen before?
Regards,
Eddy
Well Eddy, looking at the lightcurve of the past several cycles, I don't see a big difference between this minimum now and the previous ones, except for more data points, due to seasonal effects. CV's do not always have exactly the same min/max between cycles. I believe the current working definition of UGZ requires the standstill to be of sufficient length, and more in the middle ground between min/max, rather than near the bottom... Of course its a judgement call for some cases, but I really don't see much of UGZ behavior here (yet!?).
https://www.aavso.org/lcg/plot?auid=000-BBD-135&starname=KT%20PER&lastd…
I would concur with LMK that KT PER's recent behavior seems well with its normal cycle range. A true Z CAM-type stanstill for KT would likely find the star fluctuating for a time near magnitude 13.5 , or so.
However, I would hasten to add that if one observes dwarf novae long enough you do tend to see some rather peculiar behavior take place sooner or later, much of it not mentioned or acknowledged in the usual reference literature. So, Eddie, I would most definite advise you to keep a close eye on KT PER the rest of its observing season and see what it may ultimately do.
J.Bortle (BRJ)
Yes, I seem to recall a few years back SS Aur exhibited ZC-like behaviour; and KT Per does have a very short outburst period, a feature also shared by Z Cams. I don't think the distinction between the types is quite as clear as was assumed in the past!
Well, as I see, the standstill (?) lasted 7-8 days (but how did you know this in advance? :) ), then again brightened! (Or else the RX And doing such a thing.)
https://www.aavso.org/lcg/plot?auid=000-BBD-135&starname=KT%20PER&lastdays=20&start=&stop=2457616.9238312617&obscode=&obscode_symbol=2&obstotals=yes&calendar=calendar&forcetics=&pointsize=1&width=800&height=450&mag1=&mag2=&mean=&vmean=&grid=on&visual=on&uband=on&fainterthan=on&bband=on
Otherwise, the KT Per is unofficially categorized as "Z CAM Impostor".