My Astronomy




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

Astronomy Blog Index
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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NGC 6405 (M6) - the butterfly cluster in Scorpius

I used telescope T13 at Siding Spring to take this 240 second image of NGC 6405 the Butterfly Cluster.


 North is up and East is to the left.

I solved the original fits file - this is the plate solution

The image has a plate scale of 3.67 arcseconds per pixel and is aligned to within 5 minutes of North. The sky coverage is just over 1.5 degrees by 1 degree 13 minutes. The cluster is 33 minutes square so it is slightly bigger than the full Moon.

 From Burnham he describes the cluster as being "some 5 degrees north of the tail of Scorpius and about 3 1/2  degrees northwest of the similar cluster M7"  

The bright orange star is the semi-regular variable BM Scorpii. I looked this up in the AAVSO VSX catalogue:




The last observation of this star logged at the AAVSO was on the 30th September 2014 and was given a Visual magnitude of 6.3

 I generated a light curve on the AAVSO site by requesting 1000 days of observations be plotted noting from Burnham that it had a long period of about 850 days. 

 I find it difficult to see a regular variation and realise why the AAVSO table above did not specify a value for the period.


Back to the cluster itself it is believed to be at a distance of 400 to 450 parsecs according to Burnham but the WEBDA catalogue gives a more up to date value of 687 parsecs. The diameter of the cluster is about 25 light years.