Hello,
Timeseries observations of ASASSN-24hd through a V filter were done on 24
and 25 Dec 2024 at CBA KKO. They covered the epochs JD
2460669.35-2460669.48 and JD 2460670.34-2460670.51 respectively.
The LCs on both nights showed a clear periodic modulation (superhumps) in
the shape of a saw tooth, a pattern that seems to occur with many
outbursting ugwz stars seen over the years.
The amplitude of the cyclic modulation during those nights were about .25V
and .20V resp. and the mean brightness's were 12.79V and 12.92V.
A period analysis using the PDM and GLS methods with Peranso 3.0 yielded a
period of 0.583d +/- 0.003d on both nights, and considering the total
observing baseline over the two nights a mean period of 0.580d +/- .0015d
was derived.
Earlier observations done on 19 Dec (mid-time JD 2460664.38) showed the
object at a brightness of 12.06V but without any clear modulation.
From the discovery data it can be concluded that the superhumps started
between 8 and 12 days into the outburst.
The large amplitude outburst, the considerable delay in the formation of
superhumps, the LC pattern of the superhumps and the relative short
periodicity of them ought to direct towards the ugwz status of ASASSN-24hd.
Further observations are planned, weather allowing
Berto Monard / CBA KKO
Calitzdorp / South Africa