Sunday, January 13, 2008

Observation January 12, 2008

Yesterday night was the 3rd clear night of January. It's going to be a good month from an observation point of view.

The objective of this session is to continue the Herschel II list.

Location: Boutersem (Belgium)
Equipment: Celestron Advanced Newton 20cm F5
Eyepieces: 24mm and 16mm - Powermate 2,5x
Limit Magnitude 5.3
Seeing: moderate
Time from 18:30 UT to 00:00 UT with a gap of 2 hours due to clouds

Comet Holmes is still visible with the naked eye.

NGC 2366 – galaxy of mag 10.50 in Camelopardalis.
It’s a long one (7’) so surface brightness is low. Not sure I have seen it.

NGC 2274 – galaxy of mag 12.40 in Camelopardalis.
At 104x I can see it once in a while when moving the tube. It’s better visible at 154x – a round smudge of 3’. I'm not sure if I have seen a core.

NGC 2112 – open cluster in Orion
At 64x I can see 4 faint stars and 1 moderate bright star in an area of 10’. At 104x the cluster is better visible with its 9 stars. The cluster stands really loose from the background.

NGC 1662 – open cluster in Orion
This is a loose open cluster. At 64x 8 bright stars are visible, together with another 7 faint ones. 3 of those bright stars makes a triangle in the centre of the cluster with one of them being orange.

NGC 1762 – galaxy of mag 12.7 in Orion
At 104x the galaxy is almost continuously visible with averted vision. It’s a round smudge of 1’. The foreground star is only visible with averted vision but not at the same time as the galaxy. Interesting object.

NGC 1750 and 1746 – open cluster in Taurus
NGC 1746 is a large open cluster of 40’. It contains many bright and faint stars, I estimate more than 50 stars. At the west side there is a small arc of bright stars. NGC 1750 is the eastern part of NGC 1746 although I cannot see any reason for giving a new number. This just seems to be the same cluster. It’s the area with most of the bright stars. At the north-east side there is a 10’ area with a higher concentration of faint stars.

NGC 1587 – galaxy of mag 11.7 in Taurus
Suspected at 64x. Obvious at 104x but not continuously visible. It’s an oval of 3’ with its longest elongation going from NW to SE. The core is not visible. The galaxy is located between 2 bright stars. I could not look for NGC 1589 because clouds are hiding the field

NGC 1582 – open cluster in Perseus
64x. A loose cluster of 30’ with 8 bright stars and around 30 faint stars. The centre contains almost no stars. One of the bright stars is slightly orange.

NGC 1624 – open cluster and emission nebula in Perseus
At 64x I can see 3 stars laying in a nebula of 5’. At 104x one of the 3 stars is looking brighter than the other 2. The nebula is well visible.

NGC 1605– open cluster in Perseus
I can see 2 stars in the area where this cluster should be located, nothing more.

NGC 1579 – reflection nebula in Perseus
Easily visible at 64x. It’s located south of a moderate bright star. It’s around 5’ big and its shape is irregular. The centre is brighter than the edges. At 104x visibility is enhanced.

NGC 1348 – open cluster in Perseus
At 64x I see an unresolved smudge of 5’ with 2 faint stars. 5 to 6 stars become visible at 104x.

NGC 1207 – galaxy of mag 12.7 in Perseus
Probably seen at 156x – located between 2 faint stars

NGC 1193 – open cluster of mag 12.6 in Perseus
At 156x I see 2 stars and maybe an unresolved smudge. At its west there is a double star with an orange companion.

NGC 1175 – galaxy of mag 12.8 in Perseus
Maybe visible at 156x

NGC 1003 – galaxy of mag 11.3 in Perseus
At 104x it’s a smudge of 2’ located close to a faint stars. Also visible at 154x.

Up to here for Herschel II objects. I’m getting too tired to look for such faint objects. So it’s time to do something more easier.
As Canis Major is well visible now I decided to explore a bit this constellation.

M41 – no notes

NGC 2360 – open cluster in Canis Major
This is a quite concentrated cluster of 25’. At 64x it contains something like 30 stars of which none are bright.

NGC 2362 – open cluster in Canis Major
This is a cluster with a triangle shape. 20 stars in an area of 15’. A bright star is located in the middle of the triangle.

145 Cma (h3945) – double star mag 4.8 – 6.8; 26”
This is a very nice double star. The primary is orange and the secondary is blue. Well separated. Reminds me of Albireo. Beautiful. I recommend you to look for this one.

Arrowhead cluster – asterism in Canis Major
This is an asterism with 7 bright stars and has a shape of an arrowhead.

“Number 3” cluster – asterism in Canis Major
This is an asterism with 20 stars forming a shape of a “3”.

If someone knows the catalogue numbers of the last 2 objects I will be glad to hear it from you.

Up to know I have seen 89 Herschel II objects. It's in fact more because I didn't log the observation of January 6 yet when I have seen 5 or 6 HII objects. I don't think I will be able to see all of them with a 20cm scope, certainly not from Belgium. If I can see, from Belgium and the Provence, 350 oout of the 400 I think it's going to be a nice achievement.

Clear skies to you

Olivier

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