Dear colleagues
Further to my report on Nov 26th, 2022 regarding the detection of superhumps in the optical lightcurve of CSS 091019:220450+054852, we have now obtained a total of 652 observations covering a time span of 1.6 days, combining my own observations with observations kindly provided by David Messier (CBA network). This has allowed us to significantly refine the superhump period, resulting in a (long) Psh = 0.0960 +/- 0.0002d, using the ANOVA, Generalized-Lomb-Scargle, PDM and Conditional Entropy methods (Peranso 3.0). The average superhump amplitude was 0.46 mag.
Best regards Tonny
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Tonny Vanmunster CBA Belgium Observatory CBA Extremadura Observatory http://www.cbabelgium.com
PERANSO : The Light Curve and Period Analysis Software http://www.peranso.com
-----Original Message----- From: cba-chat cba-chat-bounces@cbastro.org On Behalf Of tonny.vanmunster@gmail.com Sent: Saturday, 26 November 2022 01:03 To: cba-chat@cbastro.org; 'Kenta TAGUCHI' kentagch@kusastro.kyoto-u.ac.jp; vsnet-alert@ooruri.kusastro.kyoto-u.ac.jp; 'Taichi Kato' tkato@kusastro.kyoto-u.ac.jp; vsnet-campaign-dn@ooruri.kusastro.kyoto-u.ac.jp; vsnet-newvar@yahoogroups.com; 'vsnet-outburst' vsnet-outburst@ooruri.kusastro.kyoto-u.ac.jp Subject: (cba:chat) CSS 091019:220450+054852: new SU UMa-type dwarf nova
Dear colleagues,
I have just finished analysing my unfiltered CCD observations of CSS 091019:220450+054852, obtained on 2022, Nov 25/26 at CBA Belgium Observatory, using a 0.40-m f/10.0 telescope and QHY-286M CMOS camera under clear skies.
Regular superhumps with an amplitude of 0.40 mag are very clearly visible in the resulting light curve, establishing CSS 091019:220450+054852 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 (long) superhump period of 0.0855 +/- 0.0006d. The object was at mag CV = 15.3 on Nov 25th. There's still some uncertainty on the superhump period as my session lasted 2.3h only. Hence, follow-up observations are strongly recommended.
I will send my observations to AAVSO, CBA and VSNET for further analysis.
Best regards Tonny
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Tonny Vanmunster CBA Belgium Observatory CBA Extremadura Observatory http://www.cbabelgium.com
PERANSO : The Light Curve and Period Analysis Software http://www.peranso.com