Stephan's Quintet and NGC 7331

Stephan's Quintet is the small group of five galaxies at the bottom right of the picture. The spiral galaxy to the left is merely in the line of sight. The other four galaxies are very close together and interacting.

NGC 7331 (the brightest galaxy in the picture) is a spiral galaxy of visual magnitude 9.5 and at a distance of 46 million light years. The galaxies in the top left of this picture (including NGC 7331) are often referred to as the Deer Lick Group. It is not a real galaxy group - the fainter galaxies are ten times more distant.
This galaxy is particularly interesting because it is so similar to our own galaxy. It has about the save size, a similar sized black hole at the centre and the spiral structure is also similar.

 Stephan's Quintet, as its name implies, is a group of five galaxies (NGC7317, 7318A, 7318B, 7319 and 7320)  300 million light years from Earth in the constellation Pegasus. This unusual system has often been used as proof that the redshift is not truly a distance indicator, which would completely overturn current cosmology, because although four of the galaxies have similar, large redshifts, the fifth (NGC7320), although apparently a member of the group, shows a much smaller redshift. Conventional theory states that the low-redshift galaxy is in a nearby group (the NGC7331 group) and by coincidence appears on the sky projected against a distant background group. Opponents point to debris and tails around the low-redshift galaxy, suggesting that it is interacting with the high-redshift systems, which would require that all five galaxies be at the same physical location in space.

This image was taken with a Canon 40D DSLR and Stellarview 102ED refractor @ f/5.6. 30 x 5 mins @ ISO 1600 images captured, aligned and stacked in Nebulosity. Digital Development in Images Plus and final processing in Photoshop....The Galaxies are so faint with the 102mm scope so a future imaging session with the Meade 12" scope would improve clarity.

 

Probably the most famous galaxy other than the Milky Way, the Andromeda galaxy is our nearest neighbour in space as far as large galaxies are concerned. Andromeda provides a great opportunity to astronomers as it is thought to be very similar to our own galaxy, allowing us to look at galaxies with a different perspective. It is also odd because Andromeda is one of the very few blue shifted galaxies, this blue shifting indicates the galaxy is moving towards us. Astronomers have measured the speed of the galaxy to be about 300km/s and is expected to collide with our own galaxy in approximately 2 billion years.

M31 lies in the constellation of Andromeda and is very easy to find for the amateur astronomer with almost any telescope. Even though the visual magnitude of Andromeda is very bright, +4.4mag, it is quite hard to see anything more than a smudge as it has a very low surface brightness, this is due to the physical size of the galaxy. To view detail visually it is important to have very dark skies and as much contrast as you can get.  Andromeda is probably the most photographed galaxy. M31 lies approximately 0.8Mpc(~2 million light years) away from us and is part of the local group of which m31 and the milky way are the two largest galaxies.

Like the Milky Way, Andromeda Galaxy has satellite galaxies, consisting of 14 known dwarf galaxies. The best known and most readily observed satellite galaxies are M32 & M110.

Based on current evidence, it appears that M32 underwent a close encounter with M31 in the past. M32 may once have been a larger galaxy that had its stellar disk removed by M31, & underwent a sharp increase of star formation in the core region, which lasted until the relative recent past.

M110 also appears to be interacting with M31, & astronomers have found a stream of metal-rich stars in the halo of M31 that appears to have been stripped from these satellite galaxies. M110 does contain a dusty lane, which is a hint for recent or ongoing star formation. This is unusual in elliptical galaxies, which are usually fairly low in dust & gas.

In 2006 it was discovered that nine of these galaxies lie along a plane that intersects the core of the Andromeda Galaxy, rather than being randomly generated. This may indicate a common origin for the satellites.

 This latest image of M31 was taken on 11th August 2010 at 2am....The seeing was good for my part of the world, I could see the Milky Way clearly as it crossed the centre of the sky. I witnessed about 5 Perseid meteors during my imaging run and one can be seen at bottom left of image. Images taken with a Canon 40D and Stellarview 102ED at F/ 5.6. 12 seperate images of 5 minutes, ISO 1600 were taken in Nebulosity. Processing in Images Plus and Photoshop....Copyright Keith Grice 2010

M81 and M82 in Ursa Major are two of the brightest members of the M81 group of galaxies. M81 (often called Bode’s Nebula after being discovered by Johann Elert Bode in 1774) is a large bright spiral approximately 12 million light-years distant, whilst M82 (the “Cigar Galaxy”) is an irregular starburst galaxy, highly disturbed by gravitational interaction with other members of the group.

In the region of M81 and M82 (and across large parts of the northern sky), there is a large faint nebular complex associated with dust and gas expelled from the plane of the galaxy. The region here is part of MW3, Mandel Wilson Catalog Of Unexplored Nebulae and the faint dusty areas show up faintly in a strongly stretched image of the region. This has been refered to as an “Integrated Flux Nebula” since it reflects the galaxy’s light rather than that of a single star. Also visible is Holmberg IX (below M81) which is a small, faint blue irregular galaxy also in the M81 Group.

This image was taken on the 16th May 2010 with a Canon 40D DSLR and Stellarview 102ED Refractor at F/ 5.6. Exposure time is 95 minutes, 19 x 5mins @ ISO 1600 captured, aligned and stacked in Nebulosity. Digital Development in Images Plus and final processing in Photoshop. Image has been magnified and cropped.

'Cigar Galaxy'
Located 12 million light-years away, M82 appears high in the northern spring sky in the direction of the constellation Ursa Major, the Great Bear. It is also called the 'Cigar Galaxy' because of the elongated elliptical shape produced by the tilt of its starry disk relative to our line of sight.  
 
M82 is a magnificent starburst galaxy. Throughout its central region young stars are being born ten times faster than they are inside in our Milky Way Galaxy.

M82 occupies the same region of sky as M81and is around 11 million light years away. Lying edge on to us it presents a classic cigar shape, hence it's common name. M82 is a "starburst galaxy". The core of the galaxy contains some highly energised star clusters which are emitting huge amounts of ionised hydrogen. It may be that this results from disturbance following a previous interaction with M81.

This image was taken on the 16th May 2010 with a Canon 40D DSLR and Stellarview 102ED Refractor at F / 5.6. Exposure is 95 minutes, 19 x 5mins @ ISO 1600 captured in Nebulosity. Digital Development in Images Plus and final processing in Photoshop. Image magnified 100%.