[vsnet-alert 23930] Re: (cba:chat) HW Boo: new SU Uma-type dwarf nova

Wed Feb 5 20:33:24 JST 2020

Update: based on last nights observations (2020, Feb 04/05), obtained at CBA Extremadura Observatory, HW Boo now shows full-grown superhumps with an amplitude of 0.30 mag and a (refined) superhump period of 0.0622 +/- 0.0010 d. The object was at mag 13.7 (CV) on Feb 5th.

Best regards

Tonny

From: cba-chat [mailto:cba-chat-bounces at cbastro.org] On Behalf Of Tonny Vanmunster
Sent: dinsdag 4 februari 2020 15:47
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; vsnet-outburst at yahoogroups.com
Subject: (cba:chat) HW Boo: new SU Uma-type dwarf nova

Dear colleagues,

I have collected 2 nights of unfiltered CCD observations of HW Boo (2020, Feb 02/03 and Feb 03/04) at CBA Extremadura Observatory, using a 0.40-m f/5.1 telescope and SX-46 CCD camera, under clear skies.

The first night of observations did not reveal any periodic signal. However, the second night (Feb 03/04) clearly shows the presence of low-amplitude superhumps (0.05- 0.06 mag), hence establishing HW Boo as a new SU UMa-type dwarf nova (with a chance of being a WZ Sge-type dwarf nova - future observations will need to provide clarity). A period analysis using the ANOVA, Lomb-Scargle and PDM methods (Peranso), yields a combined superhump period of 0.0630 +/- 0.0019d. This is in good agreement with the published Porb = 0.06435d (see AAVSO VSX). The object was at mag 13.7 (CV) on Feb 4th.

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

Follow-up observations are highly recommended to study the evolution of superhumps in this system.

Best regards
Tonny

-- 

Tonny Vanmunster
CBA Belgium Observatory
CBA Extremadura Observatory
www.cbabelgium.com <http://www.cbabelgium.com> 
www.peranso.com <http://www.peranso.com> 