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Tuesday 22 December 2009

Abell 12 (PK 198-6.1)

Cold: -2°C, no breeze, icy (treacherous underfoot).

Seeing Ant I (excellent seeing), transparency around II-III (mediocre). 
NELM 6.0 to 6.2, waxing crescent Moon (33% of full) just setting

Scope: 12 inch Dobsonian.

As it was a clear evening, I decided to take the scope out in slightly unfavourable conditions (ice underfoot, freezing fog forming) to have another go at Abell 12 (PK 198-6.1). While I saw it briefly the other evening, I didn't get a good enough view and I used a lower power. This evening I wanted to use a high power on it.

I eventually saw it after a LOT of averted vision staring (I think it would be easier on a better night) at 304x, located just west of Mu Orionis. It is almost right next to the star so a filter is needed to cut down the glare, I used my usual filter for PNs, an OIII. It is round, even, largish and faint. It is utterly invisible without the OIII filter. 304x + OIII

After coming back in I checked it out on the net, via Google, and people talk of it popping into view with an OIII, in various scopes, from 8 inch upwards. This was not my experience. I had to use a hood, high power and an OIII filter plus a fair bit of averted vision looking to see this, and I think the conditions were the reason I didn't get a good view - this is not a hard object, by all accounts. I definitely want to return to this on a better night.
I also had a crack at the planetary nebula Jonckheere 320, also in Orion, but no joy there. With the icing up of my Telrad and finder, things 'out in the boondocks' were not going to be easy to locate!

I did, however, take a high powered trip into the heart of M42, with my 5mm Radian (304x) and OIII filter. To say that this is an awesome sight is not doing it enough justice. It is bright and incredibly detailed, with mottling, dark areas, bright areas, the Trapezium all hitting the back of the eyes in spectacular fashion. I will do a sketch of this before the spring comes. I suppose one could ask 'why aren't all deep sky objects as easy to see as this' - but then, what would be the fun in that, if all DSOs were a piece of cake to find and see?

Now the infernal Moon - as a deep sky observer, it is hard not to loathe and detest the bloody thing - is on the way back up again (currently 33% of Full), there'll be no more deep sky observing until next month - weather permitting, of course.

Sketching or electronic imaging?

Often in astronomy the question of visual astronomy (Mark One Eyeball) vs electronic imaging (CCDs) crops up. Being very firmly in the first camp I get a tad annoyed when people assume that imaging is the only way to go about getting lasting souvenirs of a nights observing. All too often I encounter beginners who are itching to go straight past visual observing and dive right into imaging and, often, they know nothing about the sky and how to find their way around it. They don't want to know about the joy that is visual deep sky or planetary observing! They're missing the best bits!
I guess that most of the reason for this is because astrophotos are eye-catching and pretty and imagers garner a lot of praise - and rightfully so because imaging is not easy - for their work in getting the pictures. It's also been mentioned elsewhere that imagers are quicker and more keen to blow their own trumpets than visual observers and I believe there's a lot of truth in this. I love a good astrophoto as much as the next person, indeed I have astrophotos on my walls at home, but while I am grateful for the dedicated souls practicising this art I would like to discredit the notion there seems to be that it is the only way to practise amateur astronomy.
While the magazines are full of ads for wonderful electronic gizmoes and feature lovely photos of colourful swirling nebulae and mysterious galaxies and legions of 'how to' articles on imaging, there isn't a huge amount aimed at the purely visual observer, bar the usual "Such and such is in the sky and you can see it with the unaided eye/binoculars/scope". The UK's Astronomy Now and BBC Sky At Night magazines now feature regular sketching articles by Jeremy Perez and Carol Lakomiak - and this is excellent to inspire others to take up astronomical sketching, although AN is better in this regard because Jeremy gets a couple of pages while Carol, in S@N, gets a mere half page although this is better than nothing as S@N resisted featuring sketching for a long while (I wrote to the editor a few years ago about featuring sketches and got a dismissive reply, I stopped buying the magazine for a long while because of this).
People tend to think of astronomy as an expensive hobby but it isn't and, once you have a scope, you need nothing else except pencil and paper. Give visual observing and sketching a go, it is not hard and a lot easier - and more fun - that you think. Don't let the imagers have all the fun and grab all the plaudits!

Monday 21 December 2009

Winter clusters and nebulae, 20 December 2009

The first nearly cloudless evening for ages prompted me to carry out the big scope for an evening's chasing of winter nebulae. I set up the scope and left it to cool while it got dark and I gathered my stuff together. The weather has been very cold of late, with snow last Friday and subsequent days being below zero, with plenty of ice on the ground. Because of the ice, and not wanting to slip over, I didn't set up in my usual place on the patio, but further up the garden, on a concrete patch I often use as it does afford a better view of the sky (the patio is closer to the house and is more convenient for going in and out of the kitchen extension, which I use as a kind of 'observatory', with my eyepieces, charts and other stuff spread out over the work surfaces and the top of the freezer).

20th December 2009
Cold: -2
° C, stiff breeze, 78% humidity.
Some cloud on southern horizon and a waxing crescent Moon, 17% of full. NELM 6.0 TO 6.5 later. Some intermittent interference from neighbours' indoor lights (why do some people not have curtains?).
Seeing Ant II, transparency II-III

Instruments used: 12 inch f5 Dobsonian and 8x42 binoculars

After satisfying myself that the clouds were not about to spread out, they were hugging the southern horizon ('Don't even think about it, you sods!' I found myself saying out loud), I began with an attempt on IC59 and IC63 which are located close to Gamma Cassiopeiae. These are very faint nebulae and, after searching around the area with a medium power eyepiece and UHC filter I can't say in all honesty that I saw these. I saw a slight brightening in the area but that was it.The waxing 17% of full crescent Moon was a sod, surprisingly bright, and it seemed to take an age to set, if I hadn't known better I'd have sworn that the damned thing was stuck where it was!

Next was the planetary nebula IC 2003 in Perseus. This was easy to find, being located exactly halfway between Menkib (Xi Persei) and Atik (Zeta Persei) - put the Telrad finder between those two stars and you will find the nebula. It is stellar at low powers and needs an OIII filter to make it stand out and confirm the sighting. At high power it takes on a slightly fuzzy appearance. There is a slight bluish tinge to this (without the filter) and it has a definitely brighter middle to it. 101x + Lumicon UHC

IC 351 in Perseus. Slightly more difficult to find than IC 2003, it took me a search of around ten minutes to locate it, to the east of IC 2003. This is a tiny, very stellar-looking PN which is pretty bright. Definitely needs the OIII filter 'blinked' in front of the eyepiece to be certain of sighting. Does not look as fuzzy as IC 2003. 190x + Lumicon UHC

While waiting for Orion to clear the house roof (I wanted a crack at PK 198-6.1, located right next to Mu Orionis as well as to look at NGC 2024 and the other stuff in that area) I got the 8x42 binoculars out and looked at a couple of large open clusters in Taurus:

NGC 1647 in Taurus. Huge open cluster. Irregular, not quite round shape. Quite a lot of stars resolved, although hand-holding the binoculars meant it was almost impossible to count them properly. Impression of some brighter foreground stars and a lot of fainter backgrounds ones. I also looked at this with the scope but the overall impression with the scope was of a large, but not rich cluster. Nice. 8x42 binoculars

NGC 1746 in Taurus. This is even larger than N1647, almost twice its size. Contains brighter stars than N1647 but even less rich. 8x42 binoculars

NGC 1952 (M1) in Taurus. While in the area, I decided to take a look at M1, the famous Crab Nebula, as it is a number of years since I last looked at it. It can safely be said that this thing is not famous for being spectacular, as it is a rather nondescript elongated smudge of light. It is, however, famous for being the first item on Charles Messier's list of objects to avoid (for the purposes of not getting them confused with comets, which was what CM was really after) and for being observed by the Earl of Rosse at Birr Castle in Ireland, and it got the 'Crab' nickname from Lord Rosse, his sketch shows tendrils like a crab's appendages - but he had a much bigger scope than me! 190x

NGC 1907 in Auriga. Completely overshadowed by its neighbour, the vast open cluster M38, this open cluster is a nice small, rich cluster. Oval, with a number of brighter stars and a hazy background of much fainter ones. 190x.

PK198-6.1 (Abell 12) in Orion. Easy to find, being located right next to Mu Orionis, but easy to see? Not particularly due to the star's proximity. It is right in the glare from the star and it took high magnification, an OIII filter and a cover over my head to block out stray light for me to see something round, largish and faint next to the star, but I want to have another go at this when Orion is higher and the conditions are better. 190x + Lumicon OIII

NGC 2024 in Orion. Right next to Alnitak (Zeta Orionis, the eastern most belt star), this is slightly overwhelmed by the star's glare but is not hard to spot. The big dark rift  which cuts it in two is the most obvious feature with averted vision bringing out the faint nebulosity either side of it. A UHC filter works quite well on this, while OIII and H-beta kill it. The western half of the nebula, nearest the star, is brighter than the easten half. 60x + Lumicon UHC

By this time it was 2135 GMT (UT) and the clouds were moving in so I finished the session with the obligatory look at M42, the Great Orion Nebula and the detached portion M43. This, in the 40mm Plossl (38x) with the UHC filter attached, was spectacular with tendrils and nebulosity everywhere. The dark indent next to the Trapezium was very obvious as were other dark areas, giving the brightest portion of it a mottled appearance. 38x + UHC 

Packed up as the clouds began to fill the sky.

Monday 14 December 2009

Geminids

Just because I am into deep sky observing doesn't mean I don't appreciate a good bit of shallow sky action when it's happening and 13th, 14th and 15th December happen to be when you can see the annual Geminid meteor shower in 2009. It promised to be a good one, with predicted rates of 100-120 meteors an hour. The shower was due to start around 2130 UT although the best time would be after midnight UT when the radiant had risen high enough.
Still having the effects of the bad cold I had caught the previous week I went to bed early and got up at 2330 UT, dressed and carried my folding chair (a useful souvenir of the IW Festival a couple of years ago - a relative of one of my aunt's work colleagues was one of the clean up crew and there were a lot of discarded items, as-new-only-used-once items at that, afterwards, all free to a good home) outside.
In the course of half an hour I saw many meteors, at least three or four a minute, maybe more. Most of them were quite small ones, but there were also large, spectacular ones too. Something I noticed was that you'd get a short lull of a couple of minutes, then a flurry of several meteors before another short lull of a couple of minutes. It was quite a show and, with the Moon out of the way (waning crescent which rose just before 0700 UT), a big improvement over the much more famous Perseids in August which were washed out by a quarter Moon this year.
After half an hour I was getting cold and having to get up at 0600 meant that I couldn't stay outside much longer. A pity as it was shaping up to be a nice night, after cloud earlier in the evening, and I would have loved to have brought the 12 inch out for its first proper winter observing run. I got out of the chair - and my knees were so cold I thought they'd snap! - and headed in after a pleasant half an hour gazing at the sky with nothing but my unaided eyes.
Unfortunately, with a grim forecast and a cloudy sky, tonight does not look as if it will follow suit.

Sunday 13 December 2009

A few more sketches

Here are a few more sketches from the summer/early autumn. These, too, have been scanned straight from the original sketch and processed a bit in PS Elements 6. I have tried to make the stars rounder but without making them appear bloated. By the way, the light patches in the corners and sides are the result of the scanning process: my sketchbook is spiral bound and so the scanner lid does not shut properly, causing light to leak in.

Click images for larger versions.


NGC 7662 ^


M33 with HII regions NGCs 595 and 604^
NGC 604 is the elongated patch just below centre, 595 is labelled at bottom left


NGC 205^

Photoshop sketch experiment

A couple of weeks ago, I tarted up some sketches in Photoshop. A couple of these sketches were of portions of the Veil Nebula in Cygnus, and I decided that maybe they didn't look quite nebulous enough as my sketchbook doesn't have an entirely smooth surface so I tried an experiment with the Photoshop Elements Smudge Tool. I also made the stars rounder with the Blur Tool, although they turned out a bit fatter than intended, but I suppose they represent the sort of seeing we often get here!

It definitely needs a lot more experimentation to get it exactly right though. Here are the first sketches treated in this way, these are scanned straight from the original sketches as I did not bother re-drawing them from their raw state. Click for larger image.


NGC 6992/6995 above

NGC 6960 below


Saturday 12 December 2009

Binocular observing session 11-12 December 2009

Sod's Law was in action last night as I had a severe cold which prevented a proper observing session with the 12 inch, and it was the clearest and most transparent sky we have had in ages. I had spent most of the day in bed with coughs, sneezes and fever, having been sent home from work at lunchtime, but something compelled me to look out of the window at 2330, I am not sure why I expected it to be clear as most of the day had been cloudy and a bit foggy. I felt a bit better and I hate wasting clear skies so decided on a short session; besides it would have been a bit foolish to have stayed out for any real length of time and get cold.
Obviously I didn't feel like lugging the big scope out, or even one of its smaller friends, but I put on jeans, jumper and shoes and went out with the 8x42 binoculars instead. I also pulled out my UHC and OIII filters out to see what winter nebulae I could see with the binoculars.

11-12 December 2009; 2330 - 0005 GMT/UT
0.5
° above freezing
No wind
Excellent transparency apart from the odd bit of clouds on the horizon; out of 5, where 1 is bad and 5 excellent, it was 5. The seeing was reasonably steady too, Antoniadi II.
Naked eye limiting visual magnitude was 6.5

Of course, I just had to go for M42, the Orion Nebula. It is an irresistible object in any instrument, including binoculars, and is worth looking for even if it is the most observed deep sky object in the sky. I make a point of saying hello to it every year, as I do all my favourites, and I can't wait to see it in the 12 inch. Huge, very bright, fan shaped, with four stars visible in the Trapezium. Needs no filtration, although UHC brings it out slightly better (OIII not as effective). M43 also visible as a little round patch.
Also looked at NGC 1981 and NGC 1980.

I also had a (over optimistic it has to be said) look for NGC 2024, the Flame Nebula, but I did not see it. I didn't think I would in binoculars but, as they say, nothing ventured, nothing gained.

NGC 2237-8/NGC 2246; the Rosette Nebula in Monoceros.
Large, round and bright with the star cluster NGC 2244 at the centre. The nebula is only just visible without a filter, but the UHC makes it very easy to see. The OIII is also effective but it's best with the UHC.

Ursa Major was low behind the trees but M81 and M82 were above the trees and easily seen with the 8x42s.

M31 was bright and huge through the binoculars, spanning the entire field of view. The core was bright and the spiral arms extensive. Good view of the dust lanes.

NGC 869 and NGC 884; the Double Cluster
Gorgeous through the binoculars. Very rich and large with the stars easily resolved.

Trumpler 2
Small fuzzy patch just SE of DC. Also NGC 957, another hazy patch.

NGC 1499; the California Nebula. This isn't quite as easy to see as the Rosette, especially without a filter, but the UHC filter brings it out and you can see a hazy brightening of faint nebulosity extending east-west, immediately north of Menkib.

By then it was 0035 (GMT/UT) and I was getting cold and coughing a lot so I had to reluctantly drag myself away from the sky and head indoors and back to bed.

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The odds on me attending the 2010 Texas Star Party have slightly improved. I have got a temporary job until Christmas and have so far, managed to save nearly half the air fare. Hopefully, a run of employment between now and April will enable me to get there. The air fare's most of the battle, with prices ranging between £350 and £550 (of course I can't leave it too late before getting the plane ticket, must get that in January or February or it'll become more expensive), while the TSP, including accommodation, is fairly cheap and doesn't require a lot of saving for. The other big 'expense' is the cash for any goodies that might catch my eye when I am there such as a 2-inch UHC filter that I want for viewing large nebulae with my 35mm Televue Panoptic.

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I have retrieved my clear sky spreadsheet from the wreckage, scanned it twice with Norton, and loaded it onto the new computer. I had been keeping a note of the weather in the intervening period - not exactly hard when it's mostly been cloudy! - and have been able to pick up where I left off. November makes dismal viewing with two clear nights and one partially clear night in the whole month, but I wasn't able to take advantage of those clear nights unfortunately. As noted in a previous entry, it has been two months of nearly continuous wind and rain, with a large part of the UK affected by flooding.

Thursday 3 December 2009

Observing by 97% moonlight

After what has seemed like an absolute eternity (in reality it was around two months - but that's plenty long enough), I finally managed an observing session. Sure it was a very short observing session of one hour, but it was an observing session nonetheless.
The reason for this was that not only has the UK been battered by a succession of Atlantic storms leaving half the country under water, work and illnesses (a succession of nasty abcsesses) have also interfered with any hope of getting outside on the rare clear occasions.

It was clear this evening, so I set up my 12 inch Dob, despite the rising Moon which was one day past full so, as you'd expect, it was washing out the sky quite badly, an effect exacerbated by mist and high thin cloud. Despite this I decided to try an experiment. I wanted to see if NGC 404 was visible. This is a galaxy in Andromeda, adjacent to Mirach (it has the nickname The Ghost of Mirach) and it was visible. It's not that faint anyway, but it's the sort of thing you'd expect the Moon to kill stone dead. It was, as you'd expect, fainter and harder to see than usual, but otherwise visible.

Cygnus was getting low in the west but I decided to poke round there for a bit partly because it will soon be gone until next summer but also it was in the part of the sky opposite the Moon. Obviously I wasn't going to be silly and hunt for nebulae that I had no chance of seeing in those conditions but I did seek out some clusters instead, open clusters are pretty immune to light pollution. One of the clusters observed was Collinder 419. To say that this was unspectacular is an understatement. 'Boring' is probably a more accurate description. It's composed of three or four brightish stars and a few more nondescript fainter ones.

The session was short, due to the conditions, only an hour but after two months without, even an hour in crap conditions is better than nothing! Roll on the next clear night that has no Moon in the way!

It was also my scope's first outing since I made the modifications to the mirror cell, with the new collimation springs from Bob's Knobs. When I took it outside and set it up the collimation was only slightly out and it took hardly any time at all to get it spot on, a major improvement on before. My new laser collimator also works nicely.