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My Telescopes

My Main Telescope - C14 and Paramount ME

My new Paramount MyT and 8-inch Ritchey-Chretien Telescope

MyT Hand Controller

My Meade 12 inch SCT on a CGEM (Classic) Mount

My 4 inch Meade Refractor with Sky Watcher Guidescope and ZWO camera on a CGEM (Classic) Mount

Skywatcher Star Adventurer Mount with Canon 40D


My Solar setup using a DSLR and Mylar Filter on my ETX90

DSLR attached to ETX90. LiveView image of 2015 partial eclipse on Canon 40D

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About the Site

 I try to log my observing and related activities in a regular blog - sometimes there will be a delay but I usually catch up. An index of all my blogs is on the main menu at the top of the page with daily, weekly or monthly views. My Twitter feed is below. I am also interested in photograping wildlife when I can and there is a menu option above to look at some of my images. I try to keep the news feeds from relevant astronomical sources up to date and you will need to scroll down to find these.

The Celestron 14 is mounted on a Paramount ME that I have been using for about 10 years now - you can see that it is mounted on a tripod so is a portable set up. I still manage to transport it on my own and set it all up even though I have just turned 70! It will run for hours centering galaxies in the 12 minute field even when tripod mounted.


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« Day 187 Thursday 2nd October 2014 Cepheid Variable CF Cas Calculation of its apparent Magnitude and Colour Inde | Main | Day 185 Tuesday 30th September 2014 Photometry of LP Cam in NGC 1502 »

Day 186 Wednesday 1st October 2014 Transforming the QX Cas photometry.

Back to the variable star QX Cas in the open cluster NGC 7790 from Monday. I now need to transform Monday's result. For that I need to look also at the image taken through a B filter.

 Here are the results

So using these results and the previous V filter values from Monday in an Excel spreadsheet 


I get the transformed value of V = 10.201

The Variable Star Reference Index has the following data concerning QX Cas

My tests this week of photometry of variable stars are based on single images, I need to use multiple images in practice for values that would be submitted to the AAVSO or the BAA Variable Star Section. I also need to ensure comprehensive reduction and a careful choice of comparison stars.