Astronomy

Observing Log for

Session Details


Northallerton

54.3299, -1.44529

10m

Notes

I went out twice during the evening - the first observing session was dominated by Open Clusters in the Monoceros-Canis Major region of the sky. I wrote about these in an article for the Durham University Astronomical Society. The second session took me back to Coma Berenices and more galaxies.

Observations

M41 - Canis Major Open Cluster

My first stop was 41, a large open cluster in Canis Major. With Sirius already close to the horizon this was a difficult find with turbulence and trees both getting in the way. Eventually I was rewarded with a moderately populous cluster with a few bright stars. The proximity of the horizon plus the presence of the moon seemed washed out any colours in the stars.

M41 is around 200 million years old and may have been known to Aristotle in 325 BC. It contains around 100 stars and is 2300 light years away, close to another OC called Collinder 121.

M47 - Puppis Open Cluster

A stunning open cluster in Puppis. It appeared to be comprised of many scattered, bright stars with a dense region in the centre that appeared to look like a mini Hyades.

47 is 1,600 light years away and its brightest star is mag 5.7. It is estimated to be 98 million years old and in front there is a double star, Sigma 1121.

M46 - Puppis Open Cluster

A second Open Cluster, located close to M47 but dimmer overal despite seeming more populous. The overall appearance was more grainy with many fainter stars hinting at further unresolved stars beyond.

46 is around 5.5 kly away and is thought to be around 300 million years old. A planetary nebula NGC 2438 is thought to be passing through it but I could not detect this object in the telescope - the moon may have washed out this dim target.

M48 - Hydra Open Cluster

A large but seemingly scattered cluster of bright stars in Hydra. I examined this one with the 10mm Plossl and identified one yellow giant star of the three which are present. 48 is 1500 light years away and is estimated to be 300 million years old. It was catalogued by Messier but a mistake in his recording meant that its exact location wasn't identified until 1934.

Beta Monoceros

Described by William Herschel as "the most beautiful sight in the heavens" I was expecting a lot from this triple star system. In my not so well collimated scope it was a difficult to focus on all three stars but the stretched triangle shape was visible, each of the bright white stars of a similar magnitude.

M50

Located in Monoceros a very sparse region of the sky (though actually deep in the Milky Way) this compact Open Cluster was difficult to find. Working my way from Beta I located the Milky Way and then followed it until I came to the cluster. It is a compact cluster with a dense central region containing one red giant which easily stood out against the other blue-white stars.

50 is around 3200 light years away and is thought to be 78 million years old.

M53 - Coma Berenices Globular Cluster

53 is a globular star cluster located one degree northeast of alpha Comae. It was difficult to identify because of its compact nature - the bright core and outer halo made it look very similar to the galaxies I had been looking at on previous nights. This problem was compounded by the moonlight, however by increasing the magnification I could identify graininess towards the centre meaning I had found the globular cluster.

M53 is the brightest Messier in the constellation at mag7.7, and is thought to be 65,000 light years away.

24 Comae - The Spring Albireo

This is a really nice little double star - a fixed binary with a golden primary and an emerald-blue secondary component (mags 5.2, 6.5; separation 20.3") which gives it the resemblance of a smaller version of Albiereo in Cygnus, hence its moniker. Definitely one to add to the "highlights" list.

M64 - Blackeye Galaxy

I was looking forward to this as all the pictures you see look very impressive, even this one which is what you might see through a moderate sized telescope. When I found it it was disappointingly normal looking. At magnitude 8.5 it was compact and bright but I think the moonlight washed out all the outer detail meaning that the dark central patch (the black eye) was not visible. I will return to this on a moonless night.

Coma Cluster Messiers

The Coma Cluster is filled with galaxies and I was finding it difficult to identify what I was seeing. By comparing what I saw at the telescope with a detailed sky map I believe that I observed 86, 84, 87 and 89.