Deep Space

All Deep Sky pictures on this page were taken with the 10" LX200 and the HX516 CCD Camera, either at f6.3 or f3.3. The camera field of view is quite small so the LX200's ability to accurately go to a given location is important. The LX200 was unguided and hence exposures are limited to about 1 minute. Subsequently multiple 1 minute exposures are combined to produce the finished picture. I have written software which combines the images by aligning the positions of user selected stars in each one. After I click on the approximate location of my chosen stars the software refines the position of each one by calculating the 'centre of mass' of the nearby pixels. Using the star locations it then calculates the least squares solution for the best fit rotation and translation which aligns each picture with the first one.

Final processing is done with a linear contrast stretch designed to bring the brightest point in the nucleus up to about full white whilst removing the sky background to a level just below the outer fringes of the galaxy or nebula. I then apply a logarithmic stretch.


M81 in Ursa Major. Exposure 15x1 minute on 19/04/01. Distance 12 million light years from Earth. A supernova appeared in this galaxy in 1993 which I observed with a 6" Newtonian. Despite the immense distance, it appeared brighter than the two stars to the right of the picture which are in our galaxy.	M61 in Virgo. Exposure 13x1 minute on 20/04/01. This galaxy is in the Virgo cluster and is 60 million light years away. Its diameter of 100,000 light years makes it similar in size to the Milky Way.	NGC891 in Andromeda 13/11/04 17x2mins at f3.3 A fine edge on spiral galaxy with a prominent dust lane. Discovered by Caroline Herschel in 1783.Distances quoted on the web range from 10 to 43 million LY.

M64	M82

M104	NGC4672
	M51 The Whirlpool Galaxy in Canes Venatici. (28x1min at f3.3 on 01/04/02) Distance 37 million light years. Discovered in 1773 by Messier himself. The companion galaxy to the lower right is NGC5195. In colour photos M51 is bluish because it has lots of hot young stars whilst NGC5195 is yellowish with mostly older stars. The dark lines on the inside of the spiral arms of M51 are dust which is the source for these new stars.
	M74 50x1 minute exposures at f3.3 M74 is an Sc type spiral galaxy in Pisces. It is probably about 30 to 40 million light years away from Earth. Since it is face on it has a low surface brightness. Some amateurs have seen hints of its spiral structure in a 4" telescope but from Manchester it was practically invisible in the 10" which shows the effect of light pollution.
	NGC7331 is a type Sb spiral galaxy in the constellation of Pegasus. It is about 30000 light years across and is located some 50 million light years from Earth. Four other fainter galaxies are also seen in this image. They are not associated with NGC7331 but just happen to lie in the same direction from Earth. See p104 of S&T Nov 2001 for an excellent image of this galaxy.
	M 33 (NGC 598) is a spiral galaxy in the constellation of Triangulum. It shines at magnitude 5.7 and is 3 million light years away from Earth. M33, along with the Andromeda Galaxy M32, is a member of the local group. It is smaller than either M32 or the Milky Way but is a typical size for a spiral galaxy. It was discovered by Messier in 1764 but may have been seen over 100 years earlier by Hodierna.


4/1/2000 23:20GMT 135seconds	14/01/01 21:40GMT 7minutes		5/02/2000 21:50GMT 10minutes
		M27 Dumbell Nebula in Vulpecula (5x1 minute at f3.3 on 27/08/01) Messier found M27 on July 12 1764, making it the first planetary nebula ever discovered. Parts of the bright nebula are expanding at 6.8 arc seconds per century, leading to an estimated age of 3000 to 4000 years. As with planetary nebulae, the distance of M27 is not very well known with estimates ranging from 490 to 3500 light years.
		M76 11/12/04 A first attempt at colour imaging using LRGB at f6.3. Exposure times were 21/20/16/16 minutes