Category: Deep Sky

I’ve resisted imaging M51 for a while now with the feeling that the world doesn’t need yet another picture. However, my recent  rough and ready image and Dan’s work convinced me that this really is one of my favourite night sky objects. So, I gathered 60 minutes of exposure time on GRAS-3 in 5 minute sub-frames. The results, while nice to look at lacked some definition in the finer detail and I found myself wondering what rather more exposure time would do for the image. The following night I gathered another 60 minutes and, when added in, the difference was stunning. Detail in the dust lanes that had been rather blurred before leapt out of the screen and this was before any additional processing had been done.

I made several attempts at processing the results before settling on this image. I’ll probably return to this in the future and try and enhance the tidal tail of stars that have been swept out by this galactic close encounter.

While the Leo Triplet is well known, there is a fourth member of this group a little further away and it’s depicted here in this 2.5 degree field.

All three galaxies in the main triplet show signs of interaction and the group as a whole is listed in Arp’s Atlas of Peculiar galaxies as ARP 317. M66 is also listed separately as ARP 16 (Spiral with detached segments). Distance to the group is about 33 million light years and measuring this picture shows that the nuclei of M65 & M66 could be as close together as 192,000 light years. By comparison, our nearest galactic neighbour is M31, Andromeda at 2.5 million light years.

The image is a stack of 15x 3 minute exposures at ISO400 using the WO Zenithstar  70 with a Sky Watcher field flattener.  Some trailing is apparent and the individual frames could use rather more exposure time and/or a higher ISO setting.

There’s been rather a trend on this blog towards pairs recently and to continue this theme here’s an image of NGC 4567 & NGC 4568, sometimes known as the Siamese Twins. This pair of interacting galaxies are part of the Virgo cluster and for some years were considered a line of sight pairing as there’s no visual evidence of interaction.

This image is the result of a stack of 14 five minute frames taken on GRAS-4 over two nights.

This picture was taken with the Canon 75-300 zoom before I bought the Williams Optics refractor. The focal length is 190mm and this image is about one quarter of the original field. Sixteen 3 minute exposures were combined and despite the short exposure time and mis-shapen stars some detail is visible in the galaxies. Also in the frame are two more smaller galaxies, NGC 2976 is on the right and NGC 3077 is at the bottom.