Observation by Don Matthews: KQ UMa

Uploaded by

Don Matthews

Observer

Don Matthews

Observed

2019 Nov 04 - 10:52

Uploaded

2019 Nov 04 - 11:20

Objects

Lightcurve
Variable star

Equipment

Celestron 8" SCT
Nikon 7500 DSLR
V filter

Exposure

20 x 20 sec at ISO6400

Location

Fife, Scotland

Target name

KQ UMa

Title

KQ UMa

About this image

I included KQ UMa in my telescopic DSLR programme of SR/L stars by mistake - 'by mistake' because it's an RRAB star rather than an SR or L one. However, before deleting it I thought I would get some observations for a phase diagram.

According to the AAVSO Variable Star Index it has a range of 14.18 to 15.34 R1 and a period of 0.48599 days. Analysing my early results against this period gave a slightly messy fit, a better period for my data being nearer 0.4864 days, about 0.0004 days longer (assuming Windows 10 and Excel are doing the sums properly). That enabled me to home in on maxima on 21 November and 9 December 2018 and more recently on 28 October 2019. The best 'by eye' fit to these three maxima was 0.48639 days, though 0.48640 was better if earlier observations on 1 November 2018 were included. The range from my observations came out at 13.5 to 14.8 V.

Files associated with this observation

KQ UMa phase diagram_0.48639d_2.jpg (304.7 kB)

Like this image

Jeremy Shears, Dr Andrew Smith, Geof Lewis, David Basey, Dr Paul Leyland, Andrew Dumbleton

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