[vsnet-alert 20920] ASASSN-17eq: new SU UMa type dwarf nova - period refinement

[Tonny Vanmunster]

Dear colleagues,

 

I obtained additional observations of ASASSN-17eq on 2017, Apr 15/16, under clear skies (with moonlight), using the same equipment as below. I’m now able to accurately establish the superhump period, based on my combined data of Apr 13/14, 14/15 and 15/16. Using the ANOVA, Lomb-Scargle and PDM methods (Peranso), this results in a superhump period of 0.0722 +/- 0.0002d. Superhumps with an amplitude of 0.24 mag are still present. The object was at mag 14.35 (unfiltered) on Apr 15th. 

 

Observations will be sent to CBA and VSNET for further analysis.

 

Best regards
Tonny

-- 

Tonny Vanmunster
CBABelgium Observatory
 <http://www.cbabelgium.com> www.cbabelgium.com
 <http://www.peranso.com> www.peranso.com

 

 

From: cba-chat-bounces at cbastro.org [mailto:cba-chat-bounces at cbastro.org] On Behalf Of Tonny Vanmunster
Sent: vrijdag 14 april 2017 23:56
To: tonny.vanmunster at cbabelgium.com; cba-chat at cbastro.org; 'Taichi Kato'; 'ALERT, VSNET'; vsnet-campaign-dn at ooruri.kusastro.kyoto-u.ac.jp; vsnet-newvar at ooruri.kusastro.kyoto-u.ac.jp; vsnet-newvar at yahoogroups.com; 'vsnet-outburst'; vsnet-outburst at yahoogroups.com
Subject: (cba:chat) ASASSN-17eq: new SU UMa type dwarf nova

 

Dear colleagues,

I have just concluded the analysis of my 2017, Apr 13/14 and Apr 14/15 unfiltered CCD photometry sessions of ASASSN-17eq. Observations were made at CBA Belgium Observatory,  using a 0.40-m /f10.0 telescope and STT-3200ME CCD camera, under clear skies (Apr 13/14) and under strongly clouded skies (Apr 14/15), with strong moonlight. 
The resulting light curve clearly shows the presence of a superhump with an amplitude of 0.26 mag. Due to the short duration of my sessions, it is difficult to establish an accurate superhump period. A very preliminary analysis, using the ANOVA method (Peranso), yields a superhump period of 0.071 +/- 0.006d, but additional observations are required to more precisely determine Psh. The object clearly is a new SU UMa-type dwarf nova, and was at mag 14.1 (unfiltered) on Apr 13th.

Observations will be sent to CBA and VSNET for further analysis.

 

Follow-up observations are strongly recommended, for the reasons mentioned above.

Best regards
Tonny

-- 

Tonny Vanmunster
CBABelgium Observatory
www.cbabelgium.com <http://www.cbabelgium.com> 
www.peranso.com <http://www.peranso.com>