I don’t know if this is previously known, but perhaps was superhumps visible in the intermediate polar HT Cam after its outburst 2023. I have not found any previously reporting about it.
HT Cam had a very short outburst 2023-02-14 (JD 2459989), only lasted 1 or 2 days. During the outburst the star raised from mag 17 to 11.5 and was observed in AAVSO by 3 visual observers and 1 photometric. After the outburst has the star continued to be a bit brighter than before the outburst, from mag. 17-17.2 to now 16.5-16.2.
I have done a period analysis from the photometric time series that was taken right after the outburst and found a variation with the amplitude 0.3 mag and the period 0.06108 days. The humps were most prominent the first 2 weeks after the outburst, but was visible up to 4 weeks after the outburst.
VSX has the period 0.059712 for HT Cam. This should be the orbital period measured spectroscopically. It has also a spin period that is about 1/10 of this period. The period I found is 2.3% higher than the orbital period and could indicate superhumps in the system.
Apart from the month after the outburst I have not found any prominent periods for the star in the region 0.05 to 0.07. The spin period on the other hand is always prominent.
I don’t know of any reports of superhumps in HT Cam, either - there are a couple of other IPs with superhumps (CC Scl, Woudt et al. CC Sculptoris: a superhumping intermediate polar - NASA/ADS and V455 And, Araujo-Betancor et al. HS 2331+3905: The cataclysmic variable that has it all - NASA/ADS) but they have true superoutbursts, whereas HT Cam doesn’t as far as I know (you noted that the 2003 outburst was short). I’m a bit surprised that such a short outburst can excite superhumps, but superhumps can do some surprising things …
I have only basic knowledge about CV’s and would like to draw attention to this event that I found curious. From AAVSO AID was HT Cam in quiescence at JD 2459987.7 (mag 16,9), probably also at 2459988.3 (<15.3), rising at 2459989.3 (13.2), in max at 2459989.6 (11.4), descending at 2459990.3 14.9 and almost back at 2459990.6 (16.1).
There are one time series during the outburst that also shows a few humps. The variation I found was in the weeks after the outburst. I thought that the amplitude and period resembles superhumps. But the type of star and other circumstances does it less probable. But if not superhumps, what was this variation which appeared and disappeared after the short outburst?
There are known cases of true (non-magnetic) SU UMa type systems exhibiting superhumps into quiescence - most famously, V344 Lyr (Still et al. 2010, ApJLett, 717, L113; a follow-up paper by Wood et al. 2011, ApJ, 741, 105 mentions other cases). This include superhumps seen in WZ Sge in what Joe Patterson described as the final decline phase (Patterson et al. 2002, PASP, 114, 721). Also, Araujo-Betancor et al. detected what they thought was a quiescent superhump in V455 And. So, the fact that your detection was back in quiescence should be okay. The remaining question, to me, is if a short outburst can indeed lead to superhumps …
