[vsnet-alert 24366] Re: (cba:chat) ASASSN-20gd: new SU UMa-type dwarf nova

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

Dear colleagues,

Further to below, I continued follow-up observations of ASASSN-20gd. Last night's observations (June 17/18, 2020), obtaind at CBA Extremadura Observatory, now show the emergence of regular full-grown superhumps with an amplitude of 0.21 mag. Using the ANOVA, Lomb-Scargle, Generalized-Lomb-Scargle and PDM methods (Peranso 3.0, under development) methods, the combined superhump period is 0.0562 +/- 0.0004d. The object was at mag 15.3 (CV) on Jun 18th. 

Best regards
Tonny

-----Original Message-----
From: cba-chat [mailto:cba-chat-bounces at cbastro.org] On Behalf Of Tonny Vanmunster
Sent: zondag 14 juni 2020 16:12
To: cba-chat at cbastro.org; 'Taichi Kato'; 'ALERT, VSNET'; vsnet-campaign-dn at ooruri.kusastro.kyoto-u.ac.jp; vsnet-newvar at yahoogroups.com; 'vsnet-outburst'
Subject: (cba:chat) ASASSN-20gd: new SU UMa-type dwarf nova

Dear colleagues,

I have just finished analysing my unfiltered CCD observations of ASASSN-20gd, obtained during 2 consecutive nights, June 12/13 and June 13/14 at CBA Extremadura Observatory, using a 0.40-m f/5.1 telescope and SX-46 CCD camera.

On both nights, low amplitude superhumps (0.07 mag) were visible, establishing ASASSN-20gd as a new SU UMa-type dwarf nova. Combining my own observations with June 12/13 and 13/14 observations of Josch Hambsch, I performed a period analysis using the ANOVA, Lomb-Scargle, Generalized-Lomb-Scargle and PDM methods (Peranso 3.0, under development) methods. This yields a combined superhump period of 0.0559 +/- 0.0004d. The object was at mag 14.9 (CV) on Jun 14th. It is declining in brightness at approx. 0.14 mag/d.

More pronounced superhumps may still develop in the days to come, so continued observations of this object are highly recommended.

I will send my observations to AAVSO, CBA and VSNET for further analysis.

Best regards
Tonny

--
Tonny Vanmunster
CBA Belgium Observatory
CBA Extremadura Observatory
www.cbabelgium.com
www.peranso.com
 
  

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