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NGC 7331 galaxy & Stephan's quintet

 

 Wide field

At prime focus from my dark observing site (Rookhope) I got a view showing both NGC 7331 (on the left) and the group of galaxies known as Stefan's Quintet (on the right):

Photo of NGC7331 and Stefan's Quintet

Canon EOS5DMkII 254mm Newtonian @ 1200mm 32 x 30s f/4.8 ISO6400 2011-01-06 19:21:05-19:40:38 UT
From Rookhope 54.8N 2.1W 330m asl. Rural, almost no light pollution (3 Bortles)

 NGC 7331

The galaxy NGC 7331 is in the constellation of Pegasus. It is rather similar to M31 (and therefore to our own Milky Way) but it is much further away, at a distance of 50 million light years. My photo also shows some of its dwarf satellite galaxies.

The galaxy NGC 7331

Canon EOS5DMkII 254mm Newtonian @ 1200mm 65 x 10s f/4.8 ISO6400 2009-9-26 21:26:52-21:44:07 UT
From Whitley Bay 55.1N 1.5W 10m asl. Suburban, significant light pollution (6.5 Bortles)

Here is a map showing where some of the small satellite galaxies of NGC7331 can be found in the photo above:

Map of satellites of NGC 7331

 Stephan's quintet

In one corner* of the full photo from which the above was cropped, it is just possible to make out Stephan's quintet of interacting galaxies. The nearest one of the 5 (NGC 7320) is about 40 million light years away but the others are, according to latest research, some 300 million light years away!

Photo of Stephan's quintet from suburbia

Canon EOS5DMkII 254mm Newtonian @ 1200mm 65 x 10s f/4.8 ISO6400 2009-9-26 21:26:52-21:44:07 UT
From Whitley Bay 55.1N 1.5W 10m asl. Suburban, significant light pollution (6.5 Bortles)

Map of Stephan's quartet

* Having been cut from the corner of the original 36 x 24mm frame, it is evident that the star images in the last photo are far from circular. This is due to photographing at the prime focus of a short focal length Newtonian telescope. Such instruments inevitably suffer from a type of off-axis optical aberration called coma. Other photos I have taken through a Barlow lens have a smaller angular field of view which makes the coma less obvious and also, to some extent, the diverging Barlow lens compensates for it.

 Better view of the quintet

The above was from light-polluted suburbia. From a much darker site I got this:

Photo of Stephan's quintet from dark site

Canon EOS5DMkII 254mm Newtonian @ 1200mm 65 x 30s f/4.8 ISO6400 2011-01-06 19:47:05-20:24:53 UT
From Rookhope 54.8N 2.1W 330m asl. Rural, almost no light pollution (3 Bortles)

 Finder chart

This chart was created by a chart generator application I wrote. It uses the Hipparcos and Tycho star data.

Finder chart for NGC7331 and Stephan's quintet

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