Deep sky observing report

M44, M67, M51, Collinder 70, Coma Star Cluster, M 65, M66, M35, NGC 2158

Friday night I visited Sourbrot (Belgium), one of my favourite dark
sky sites, together with 7 other observers from the local astronomy
group. As I got out of the car, I immediately noticed that the sky
was very transparent. The constellation of cancer was completely
visible to the naked eye, with at its heart the big star cluster
M 44. I got out my 7x50 binoculars and scanned the area for
M 67, the other Messier object in cancer. It was visible just 1.25
degrees west of Alpha Cancri (Acubens).

After setting up my telescope (8-inch f/10 Klevtzov-Cassegrain) I
aimed it at M 67. It is a very rich cluster. At 100x I counted about
50 stars. at higher magnification more stars popped into view.
The stars are spread over an area of 30'. There are several
chains and clumps of stars, but also a few dark lanes, with no
stars at all. There was no glow of unresolved stars.
To the northeast a bright star was visible. There are not many
stars that form patterns (like triangles, squares etc.) so sketching
it quickly was impossible. This will take you at least two hours
if you are a beginner (like me), so I decided to leave the
sketching for a next observing night. For more information
(including finder chart, basic data and eyepiece impression)
pleas follow this link

http://www.backyard-astro.com/pMachi...?id=49_0_1_0_M

After observing M 67 for almost an hour I took a short break. I
noticed that Leo was already high in the eastern sky. To
the north east of Leo lies Coma Berenice, the only
constellation that is named after a real person, queen
Berenice II of Egypt. The Coma Star Cluster was visible
to the naked eye. This is a beautiful binocular object. In 7x50
binoculars it filled almost the whole field of view (6 degrees)
with bright stars. For more info on the
Coma Star Cluster please follow this link.

http://www.backyard-astro.com/focuson/focuson.html

and choose Coma Berenice

In the west, Orion could be found. I pointed the 7x50 at
Collinder 70 (Orion's belt), a stunning view. I did not count
the stars, but I estimate that I saw at least 40 to 60 stars splashed
over the 6 degree field of view, with the three bright Belt stars
in the centre.

I returned to my telescope and the next half hour I spent with M 51
and its companion NGC 5195, in Canes Venatici. I immediately
spotted the two bright cores of the galaxies. I could not detect the
spiral arms of M 51,but using averted vision I saw the big outline
of the galaxies disk as a very faint, grey circular smudge of light,
at least 7 to 8 arc minutes wide. From my own light polluted
backyard, this would be impossible. I only see the two bright
cores from there.

Then, I had a look at M 35 and NGC 2158 through a 10-inch dobson.
This is definitely my favourite couple of open clusters. They where
visible in the same field of view, using a low power eyepiece.
M 35 was completely resolved, while NGC 2158 was a glow of
unresolved stars. Just imagine that M35 lies at a distance of
2.800 light years, while NGC 2158 lies at a distance of 14.000
light years, five times as far as M35!

Finally that I had a look at M 65 and M 66 through an 8-inch Vixen
Klevtzov- Cassegrain. This couple of galaxies in Leo was very
easy to detect, much better than in my own backyard. As I was
looking at M 65, the clouds started to cover the sky.

Sunday night, I observed M 44 from my own backyard, using 15x80
binoculars, mounted on the sky window. This is a true binocular
object. The conditions where good (for two hours). I could see all
the major stars that form the Constellation of Cancer, including the
two stars north and south of the Praesepe M44), Asellus Borealis
and Asellus Australis, with the naked eye. Even M 44 was visible
using averted vision. M 67 was only visible in binoculars.
In the 15 x 80 I counted about 50 stars. Just south of the clusters
centre, a triangle of almost equally bright stars was visible,
Burnham 584. I don't know if it was my imagination, but I suspected
a hint of yellow or orange in the star at the tip of the triangle.
In the next two hours I stayed with this big open cluster and tried
to make a sketch of it. At 00.15 hours UT on Monday morning
the clouds again covered the sky, but it had been a great
weekend of deep sky observing.

For a sketch I made last night of M 44 please follow this link:

http://www.backyard-astro.com/pMachi...?id=51_0_1_0_M

Clear Skies !
Math
http://www.backyard-astro.com