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


Monday, January 7, 2008

PK 111-2.1 (Hubble 12) - bis

As I said in my previous post, whenever it will be clear again I will look once more for Hubble 12. Yesterday, January 6 was clear and yes, I can confirm I saw PK 112-2.1 without any doubt with my 20 cm scope

At 64x it was easily visible as a stellar object, and it reacted positively on an OIII filter. At this magnification I could see only 1 star next to the nebula. But at 104x I could see the 2 stars next to the nebula exaclty like on my finder chart. The object itself remains stellar at 104x

I have seen yesterday evening many other objects from the HII list and other planetaries, but that's a topic for another post.

Clear Skies


Saturday, January 5, 2008

PK 111-2.1 (Hubble 12)

In my previous post I talked about my observation of PK 111-2.1. This is what I mentioned:

PK 111-2.1 – planetary nebula of 2” of mag 13.0 in Cassiopeia
This nebula is situated next to 2 faint stars. So I should see 3 stars, but unfortunately I can see only 2. One star is a bit brighter than the other one. Both stars are of mag 11.5 and 11.7 so I have to conclude I don't seen PK 111-2.1. Who could confirm the nebula is fainter than those 2 stars? Note: gives magnitude 14.0. Eye&Telescope gives mag 13.0

Well, after some discussions on the dutch astronomy mailing list it seems I have been able to see the planetary. The nebula itself is of magnitude 11.9, the central star is of magnitude 14.0.
A picture of confirms the situation (I'm not sure I'm allowed to post this picture, so if you are interested please go to the blackskies website).

Whenever the sky is clear I will observe once more this object.

Clear Skies


Friday, January 4, 2008

Observation January 2, 2008

This is the first observation this year with a telescope. It's quite cold (something around -3 °C). I'm going for a few Herschel II objects and planetary nebula's

Location: Boutersem (Belgium)
Material: Celestron Advanced GoTo Newton 20cm (8") F5
Eyepieces: Panoptic 24mm and Nagler 16mm - Powermate 2,5x
Naked Eye Limit Magnitude: starting with less than 5.0, ending with somewhat higher than 5.0
Seeing: moderate
Timing: 18:00 UT to 22:30 UT

But we'll start with 2 comets.

Comet Holmes
Visible with naked eye. But it's difficult because it's not yet completely dark. Through the 7x50 finder Holmes is a large round object but still difficult to see. Also at 42x the comet is hardly visible. I can see some nebulosity in the shape of an arc. This arcs becomes a bit more visible with a deepsky filter. Now I can see half of a circle. What a difference with the observations during October and November.

Comet Tuttle
Tuttle is not visible with the naked eye. It's barely visible with my binoculars. But through the finder (7x50) Tuttle is round with a small but bright core. At 64x I can see a coma of 10' with a faint nucleus. The coma is surrounded by some nebula which is round and 25' large. One star is visible through this nebula. A deepsky filter enhances the visibility. The shape looks more triangular than round.

M33 en NGC 604 – galaxy and HII region in Triangulum
NGC 604 is visible at 64x with deepsky filter. It's surprisingly easy to see although averted vision is necessary. At 154x (and deepsky filter) the object is elongated (2:1) and one side seems brighter than the other one.

NGC 513 – galaxy of mag 12.9 in Andromeda
This is a Herschel II object. Difficult. Only visible at 156x and with averted vision. Size is 2’.

NGC 499 – galaxy of mag 12.2 in Pisces
This one is in the neighbourhood of NGC 513. At 156x it's quite easily visible with averted vision. NGC 499 has an oval shape of 3'.

NGC 507 – galaxy of mag 11.3 in Pisces
Also this one is in the neighbourhood of NGC 513. At 156x NGC 507 is a large round object of 4 to 5' with a small core. More difficult than NGC 499.

NGC 7640 – galaxy of mag 11.3 in Andromeda
This is a very difficult object. It's 10' long (!) and hence it has a low surface brightness (SB: 14.5). According to Eye&Telescope the contrast reserve is -0.25, so it would not be visible with my scope. Indeed, at low power I see nothing at all. Maybe, but I say maybe, I can see the South-East side at 154x.

NGC 214 – galaxy of mag 12.2 in Andromeda
At 104x I can see an oval of 3'. Averted vision is required to see this object. The elongation is 2:1 and the direction is NE-SW.

These were the Herschel II objects. Now we have some planetary nebulas in Cassiopeia.

IC 289 – planetary nebula of 35” of mag 13.3 in Cassiopeia
From time to time visible at 154x with OIII filter. It's very difficult, but once in while a disc is visible.

IC 1747 – planetary nebula of 13” of mag 12.1 in Cassiopeia
This one is visible with direct vision at 154x without the aid of any filter. I see a little disc with a bright centre. It reacts very well with an OIII filter.

PK 119-6.1 – planetary nebula of 8” of mag 12.2 in Cassiopeia
At 156x PK 119-6.1 is easily visible as a "star". Observation is confirmed with an OIII filter because it reacts very well.

PK 118-8.1 – planetary nebula of 9” of mag 12.5 in Cassiopeia
Also this one is looking as a star at 156x. Observation is confirmed by OIII and UHC filter. The faint star of mag 12.9 near the nebula was not visible.

PK 111-2.1 – planetary nebula of 2” of mag 13.0 in Cassiopeia
This nebula is situated next to 2 faint stars. So I should see 3 stars, but unfortunately I can see only 2. One star is a bit brighter than the other one. Both stars are of mag 11.5 and 11.7 so I have to conclude I don't seen PK 111-2.1. Who could confirm the nebula is fainter than those 2 stars? Note: gives magnitude 14.0. Eye&Telescope gives mag 13.0

After all those faint objects it is time for showpiece such a M42 and M43. This was only for a short period, because my Celestron Powertank ran empty. This is strange because it was completely charged before starting to observe. It's a pity because I wanted to continue for 1/2 hour with Herschel II objects in Auriga and Taurus.

Anyway, the evening is a success: 2 comets, 3 HII objects and 4 new planetary nebulas.

Clear skies to you

Observation January 1, 2008

Around 10 pm UT the sky has brightened up partially. Comet Holmes is still visible with the naked eye. With the binocular I can see Holmes and M34 in the same field of view. Both are looking like 2 round patches of light. Holmes is however larger than M34. I tried to look for Comet Tuttle, which is not visible, nor with naked eye, nor with binoculars.

Tuesday, January 1, 2008

My Next Project

Since 3,5 years I'm back in Astronomy I completed 2 projects: the Messier list was completed in 2006 and the Herchell 400 list has been recently completed early December 2007. I really enjoyed doing those projects because it's like an objective to pursue. It's rather long term (takes more than a year to do), it needs good planning, patience is key but also perseverance. I like to be under the stars with a list to complete, if you know what I'm meaning.

So what’s next?

I’m thinking about 2 possible projects. The Herschel II list is the first one. I’m not so sure the 400 objects can be done with a 20cm scope, but I’ll try to do a maximum of it

The 2nd project is based on a fantastic accomplishment of a Dutch astronomer. He has been able to observe 282 planetary nebulas with a 20cm scope. Can you imagine the performance?
So I’m currently making a list of all planetaries above -30° and brighter than 14.3. It’s a list of 312 objects but I’m sure not all of them are visible. The list is based on and Eye&Telescope planning software.

So I’ll start once the sky is clear, which is hopefully for not too long now. I’m eager to start those 2 nice projects …

Clear skies to all of you.