[vsnet-alert 24489] Re: [vsnet-outburst 25445] M31V1113 = RX J0044.3+4134 = AT 2020plo: not likely early superhumps

[Tonny Vanmunster tonny.vanmunster@gmail.com via vsnet-alert]

Dear Taichi,

 

I think you have not correctly read my email. There are of course no (early)
superhumps in the data sets you have analysed. That is exactly what I wrote
in my email: "... over the past 6 nights, showing very small amplitude,
irregular variations". I had analysed these data myself, also finding the
period and aliases you mention below, but given the very small amplitude, I
did not even consider this certain enough for reporting.

 

It is only with the data set of July 27/28, which you do not have available,
that modulations have started to change in this system. Variations have
become much more pronounced (0.16 mag amplitude instead of 0.03 mag !),
starting to show a pattern of what I reported as "appears to be early
superhumps", and leading to the statement of a likely classification as WZ
Sge-type dwarf nova. I clearly mentioned "to be confirmed through further
observations", hence I hope the uncertainty in my interpretation was
sufficiently clear.

 

I have meanwhile inspected my newest data of last night (July 28/29), a 4.9h
unfiltered session, which take away further uncertainty about this system.
The light curve shows very clear 0.17 mag superhumps, indicating that my
observations of yesterday (July 27/28) were revealng the emergence of
regular (not early, you're right on this) superhumps. It is safe to conclude
that the system is an SU UMa-type dwarf nova. More news in a fews minutes.

 

I will send you both the July 27/28 and July 28/29 data sets also in a few
minutes, for your further analysis.

 

Best regards

Tonny

 

 

-----Original Message-----
From: vsnet-outburst
[mailto:vsnet-outburst-bounces at ooruri.kusastro.kyoto-u.ac.jp] On Behalf Of
Taichi Kato
Sent: woensdag 29 juli 2020 7:24
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Subject: [vsnet-outburst 25445] M31V1113 = RX J0044.3+4134 = AT 2020plo: not
likely early superhumps

 

M31V1113 = RX J0044.3+4134 = AT 2020plo: not likely early superhumps

 

> A period analysis using the ANOVA, Lomb-Scargle, 

> Generalized-Lomb-Scargle and PDM methods (Peranso 3.0, under 

> development), yields a combined superhump period of

> 0.0705 +/- 0.0028d, but given the short baseline this value obviously 

> needs to be refined over the next nigths.

 

   My analysis (not including the Jul 27/28 data) yielded a period of
0.06729(6) d (aliases 0.07210 and 0.06729).

Singly peaked and not likely early superhumps.

The amplitude was very small (0.028 mag).

The amplitude of early superhumps is usually largest around the peak
brightness and does not emerge later.

 

   The mean fading rate (0.059 mag/d) is also too small for the early
superhump stage.