AAVSO: American Association of Variable Star Observers

Proposal #91

Proposer (3522) Bart Staels (STAELS.BART.BVBA@PANDORA.BE) obscode: SBL
Assigned To(3663) Dirk Terrell
Date SubmittedNov. 26, 2018

HS 0229+8016 was identified as a cataclysmic variable star during follow-up observations of optically selected CV candidates from the Hamburg Quasar Survey by Aungwerojwit et al. [1]. Its orbital period is 232.550 ± 0.049 min (0.16149 d).

The light curve over the last 12 years appears to show almost continuous low amplitude outbursts of ~0.7 mag for much of the time. Each outburst lasts ~12 - 14 days and the star varies between mag ~13.6 and 14.3. There are two intervals of 100 - 200 days when these appear to reduce or even stop. This is reminiscent of Z Cam behaviour, although this classification is by no means certain. Prof. Boris Gänsicke (University of Warwick, UK) suggests that the low amplitude could mean that only part of the disc takes part in the outbursts, so it may be very close to the borderline of disc stability.

Boris has suggested that intensive observations over a few outburst cycles may shed further light on the behaviour of the system. I would therefore like to request observations of HS 0229+8016 from now and continuing for the next three months (until end Feb 2019). I would like one (or a few) observations per night to define the overall outburst light curve and whether there is a quiescence period between outbursts. CCD observations with a V-filter are preferred

Target RA (H.HH) Dec (D.DD) Magnitude Telescope Observation Frequency Expiration Date Proprietary Term
HS 0229+8016 2.599508 80.49561 13.6–14.3 6 Months


(3663) Dirk Terrell — Nov. 28, 2018, 10:12 a.m.

Note from Arne:
"Technically, there is no problem in monitoring HS0229+8016. At V=14, it should be fairly easy with TMO61 and SRO. The field is relatively uncrowded. It is too faint for any of the BSM systems. If approved, I'd suggest getting a 3-exposure dataset every 2 hours or so during the night. One option would be to use TMO61 for the even HA hours and SRO for the odd ones. Probably 120 second V-band exposures would be adequate. This is a good season for extensive coverage of the target."

Comments on this proposal are closed.