ASASSN-23aw: new SU UMa star
Using observations by Josch Hambsch, superhumps have
developed since Feb. 23. The period is 0.0520(1) or
0.0549(1) d (rather difficult to determine due to
the low sampling rate).
Re: MASTER OT J055845.55+391533.4: new SU UMa-type dwarf nova
> The resulting light curve clearly shows the presence of regular superhumps
> (4 in total) with an amplitude of 0.20 mag, establishing MASTER OT
> J055845.55+391533.4 as a new SU UMa-type dwarf nova.
The object is unusual in that it almost regularly showed
a deep dip during past outbursts. There were sometimes
variations like oscillations after the dip, and the overall
behavior resembles a double superoutburst.
2018 Apr., 2019 Mar.-Apr., 2020 May, 2021 Jan.-Feb.,
2021 Sep. all showed this feature. There was, however,
no fading tail looking like an AM CVn star. The number
of normal outbursts was smaller than that of superoutbursts.
Please continue observing, since a dip is expected within
a week. Recording variation of superhumps during the entire
course of a superoutburst is very important to see what
is happening.
Dear colleagues,
I have just finished analysing my unfiltered CCD observations of MASTER OT
J055845.55+391533.4 obtained on 2023, Feb 22/23 at CBA Extremadura
Observatory (Spain) using a 0.40-m f/5.1 telescope and SX-46 CCD camera
under relatively clear skies.
The resulting light curve clearly shows the presence of regular superhumps
(4 in total) with an amplitude of 0.20 mag, establishing MASTER OT
J055845.55+391533.4 as a new SU UMa-type dwarf nova. A period analysis,
using the ANOVA, Generalized-Lomb-Scargle, PDM and Conditional Entropy
methods (Peranso 3.0) yields a combined superhump period of 0.0553 +/-
0.0004d. The object was at mag CV = 14.4 on Feb 23rd.
I will send my observations to AAVSO, CBA and VSNET for further analysis.
Best regards
Tonny
---
Tonny Vanmunster
CBA Belgium Observatory
CBA Extremadura Observatory
<http://www.cbabelgium.com> http://www.cbabelgium.com
PERANSO: The Light Curve and Period Analysis Software
http://www.peranso.com
GDSJ0703457-063947: IW And star
Using ATLAS forced photometry (Tonry et al. 2018;
Shingles et al. 2021), this object turned out to be
an IW And star (typical behavior in 2022). The variation
was more heartbeat-like in 2020-2021, when the object
was slightly brighter. This may be a suggestion of
various IW And-type behavior depending on the mass-transfer
rate.
MASTER OT J055845.55+391533.4 superhumps?
Kiyota-san reported observations. The data appear consistent
with a longer superhump period of a hydrogen-rich system.
The data, however, were not enough and more observations
are needed (the outburst behavior is unusual for ar ordinary
SU UMa star).