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Leo's tail & Virgo's Cluster

Melotte 111, the Coma star cluster

Canon EOS5DMkII 100-400mm @ 300mm f/5.6 17x30s ISO6400 2011-04-03 20:47:01-20:56:13 UT
From Rookhope 54.8N 2.1W 330m asl. Rural, almost no light pollution (3 Bortles)

To the naked eye the main feature of the small constellation Coma Berenices is a faint star cluster, number 111 in Melotte's catalogue. It spans about 5° so it will not fit into a telescopic field of view and has to be photographed with a camera lens only.

The cluster has been described as the Lion's Tail and the following image illustrates why. The two white rectangles show the positions of the preceding and following images.

Annotated image of Leo, Coma Berenices and part of Virgo

Canon EOS5DMkII 24-105mm @ 24mm f/5.6 18x30s ISO6400 2011-04-03 22:44:18-22:57:44 UT
From Rookhope 54.8N 2.1W 330m asl. Rural, almost no light pollution (3 Bortles)

Are on the border of Coma and Virgo

Canon EOS5DMkII 100-400mm @ 300mm f/5.6 34x30s ISO6400 2011-04-03 20:59:37-21:19:34 UT
From Rookhope 54.8N 2.1W 330m asl. Rural, almost no light pollution (3 Bortles)

The 3 white boxes above indicate the positions of the telescopic views of details in the Virgo cluster, below (click on the thumbnails to see the images larger).

Not visible to the naked eye, Coma is full of galaxies. This is partly because the constellation contains the North Galactic Pole, in other words the direction normal to the plane of the Milky Way and therefore free of obstructions so we can see clearly to a great distance. But also there is a real cluster of galaxies, interacting with each other gravitationally. The cluster is thought to contain up to about 2,000 galaxies. It stretches south into the constellation of Virgo and the main concentration lies there, so it is called the Virgo cluster. Its centre is about 54 million light years from us.

The image on the right looks uninteresting but at its full size (3744 x 5616 pixels) a large number of galaxies can be seen in it. Here is an example from just right of the centre of the image on the right, M100 and another galaxy, enlarged to full scale (1 pixel in the camera = 1 pixel on the screen):

Enlarged view of M100

 M90 & M89


Thumbnail of M90 and M89

 M86 & M84


Thumbnail of M86 and M84

 NGC 4216

A galaxy

Thumbnail of NGC4216

I made a mosaic covering many degrees just south of the Coma/Virgo border. I have annotated it with the names of the main galaxies. Click on the thumbnail to see it properly.

Thumbnail of Virgo cluster mosaic

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