[vsnet-alert 21601] Re: DDE 76 supercycle

[Josch Hambsch]

I have taken a time series of DDE76 last night. 
Data are sent for further analysis to Kato et al.

Regards,

Josch
-----Original Message-----
From: vsnet-alert [mailto:vsnet-alert-bounces at ooruri.kusastro.kyoto-u.ac.jp] On Behalf Of Denis Denisenko
Sent: Sonntag, 19. November 2017 13:30
To: vsnet-alert at ooruri.kusastro.kyoto-u.ac.jp
Subject: [vsnet-alert 21600] DDE 76 supercycle

Rod Stubbings has reported the recent activity of this dwarf nova in Pictor with unkonwn orbital period.

DDE 76 = 1RXS J052113.4-520311
  20171111.512   140  Stu.RASNZ
  20171113.510   155  Stu.RASNZ
  20171118.537   140  Stu.RASNZ

Archival light curve from ASAS-SN (Shappee et al., 2014; Kochanek et al., 2017):
https://asas-sn.osu.edu/light_curves/9d78cc08-7eb7-48ea-b110-e401d54bb74c

It shows several superoutbursts with an average interval 145 days between them. Maxima detected by ASAS-SN:

2456934.81506 13.685  ASAS-SN
2457080.55822 13.586  ASAS-SN
2457223.92781 13.649  ASAS-SN
2457378.64750 13.457  ASAS-SN

Superoutburst around JD=2457530 was missed due to the seasonal gap.

2457680.85136 13.575  ASAS-SN
2457829.58150 13.354  ASAS-SN
2457951.94554 13.522  ASAS-SN

Best covered superoutburst at JD=2457829 was showing 0.1 mag/day fading rate over 10 days.

Since the supercycle varies between 122 and 155 days, the next superoutburst should occur anytime around JD=2458076 and JD=2458100 (Nov. 18 - Dec. 12) or may have already started. Probably Nov. 11 detection at 14.0m was a precursor. Usually normal outbursts in ASAS-SN data were no brighter than 14.4-14.5m with a couple exceptions at 14.0m.

Denis Denisenko
http://scan.sai.msu.ru/~denis/VarDDE.html


---
Diese E-Mail wurde von Avast Antivirus-Software auf Viren geprüft.
https://www.avast.com/antivirus