[vsnet-alert 24139] Re: (cba:chat) ASASSN-15kd: new SU UMa-type dwarf novae

[John.R.Thorstensen at Dartmouth.edu]

I took a spectrum of a roughly 17th mag star on this 
position in 2017 March, and found it to be an ordinary G star.
This is very likely a chance superposition; the 
CV evidently gets much fainter than this star,
so its range of variability is larger than it 
might appear.

John Thorstensen



On Fri, 3 Apr 2020, Tonny Vanmunster wrote:

> 
> Dear colleagues,
> 
>  
> 
> I have collected 4 nights of unfiltered CCD observations of ASASSN-15kd (2020, Mar 25/26, 29/30, Mar 31/Apr 01 and Apr 02/03), using
> my CBA Belgium Observatory and CBA Extremadura Observatory telescopes.
> 
>  
> 
> During the first two nights, there was hardly any periodic modulation in the observations. However, the data from Mar 31/Apr 01 and
> Apr 02/03 show well developed superhumps with an amplitude of 0.18 mag, hence establishing ASASSN-15kd as new SU UMa-type dwarf nova.
>  Using 4 different period analysis methods [Lomb-Scargle, Generalized Lomb-Scargle, PDM, ANOVA] (Peranso 3.0), the combined superhump
> period is 0.0843 +/- 0.0045d. ASASSN-15kd was at mag 16.8 (CV ) on Apr 03rd.
> 
>  
> 
> Observations will be sent to AAVSO, CBA and VSNET for further analysis.
> 
> Follow-up observations are highly recommended to refine the superhump period and to study its further evolution.
> 
>  
> 
> Best regards
> 
> Tonny
> 
> 
> --
> 
> Tonny Vanmunster
> CBA Belgium Observatory
> CBA Extremadura Observatory
> www.cbabelgium.com
> www.peranso.com
> 
>  
> 
> 
>

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John R. Thorstensen
Department of Physics and Astronomy
Dartmouth College
6127 Wilder Laboratory
Hanover, NH 03755

Office: 239 Wilder Hall
Phone:  603 646 2869     Fax: 1446   Hinman Box 6127
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