Archive for the “Writing” Category
Feb
03
2012
I have gone for one of my “single bright star” images for this Month’s “Image of the Month”. This Month’s object is the star Procyon or 10-Alpha Canis Minoris in the constellation Canis Minor. Procyon shines brightly in this region of sky at magnitude 0.40 and part of the reason it is so bright is that it is very close to us at just 11.41 light years. With an F5IV-V spectrum, Procyon appears bright white in the sky, and also in this image. You don’t need very long subs when imaging bright stars, but if you want to capture a decent number of background stars you need to use subs from 3-5 minutes long. In order to reduce the noise it is a good idea to get at least a couple of hours of total exposure time, though if conditions are favourable you will get a good result with just an hour or so. As this image was taken with the Sky 90 refractor it is clear that the spikes are “software spikes”. When a single star is the subject of the image I prefer to see some spikes rather than a bright ball of light with an extended fuzzy outline – but that is just personal preference. There are some cases (M44 immediately comes to mind) when I prefer no spikes at all, it depends a great deal on the subject and its setting. There isn’t much apart from Procyon in this region so this one is a case of all or nothing, only really worth taking if you are building up a portfolio of the brightest stars in the sky. Until next month – good imaging
Jan
29
2012
Reprocess and crop to the Double Cluster and Stock 2Posted by Greg Parker in mini-WASP Array
Jan
04
2012
This is precisely the sort of image the mini-WASP array was designed to capture!Posted by Greg Parker in mini-WASP Array
Jan
03
2012
Some earlier Stock 2 data added to the mini-WASP Double Cluster imagePosted by Greg Parker in mini-WASP Array
Jan
03
2012
Double Cluster from the mini-WASP array just before grabbing the lunar halo imagePosted by Greg Parker in mini-WASP Array
Managed to get half an hour on the Double Cluster with one camera before it all went pear-shaped with the weather last night. The Double Cluster and Stock 2 is one image that the mini-WASP array was actually designed for
First off, a very Happy New Year to you all. Well – 2011 can’t be said to have been the best imaging year on record, in fact I think it is fair to say that it is the worst imaging year overall I have recorded in my log book – and that goes back to September 2004. Let us at least hope for a better year, weather-wise, this year. So what is this month’s Imaging Object of the Month? I have decided again to steer clear of the Orion goodies and move to nearby Auriga. Now Auriga usually means IC410/IC405 the Flaming Star nebula – but lying very close by there are a bunch of very nice open clusters and some smaller regions of emission nebulosity. So my Imaging Object for this month is the M38 open cluster region in the constellation Auriga. M38 (NGC1912) is quite a sizeable open cluster at 15 minutes in diameter and pretty bright at magnitude 6.4. Lying just underneath M38 you can see another little open cluster – NGC1907 – which very nicely offsets the subject of the image, M38. I have both clusters offset from the centre of the image as this is part of a much larger mosaic which will eventually include M36, IC417, IC410 and IC405. As per usual with any open cluster you don’t need to use particularly long subs but as I wanted to catch the outer fringes of all the emission nebulosity surrounding IC410 and IC405 (which you can see towards the top right of the image) I used 5-minute subs with the fast f#2 Hyperstar III system – so this image goes pretty deep. As usual, you need at least 4 hours worth of data to start getting on top of the noise in the faint regions. Plenty of stars, plenty of faint nebulosity, the M38 region is certainly worthy of your valuable imaging time. Until next month – clear skies |







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