Friday, 30 July 2010

20" project

As mentioned in my previous post, I have the opportunity to buy a 20" Dob from someone on the mainland. He transferred the optics to a permanently-mounted equatorial scope and now has the empty scope for sale. All being well, I am going to buy this from him and get a new mirror to fit it and the cost of the entire project should be less than ordering a brand-new, scratch-built custom scope. The original mirror was an f/3.7, so I am either going to have to get a 20" f/3.7 mirror made, which will be slightly pricier than a standard f/4, or get an f/4 and alter the scope by adding longer truss poles, new secondary holder, changing the position of the attachment blocks, and so on, but by the time I've done all that, I may as well spend the extra couple of hundred quid on an f/3.7.
I'll need a Paracorr as the coma will be bad with such a fast mirror, but I can live with that, it'll be worth it to have large aperture! But, we're getting ahead of ourselves - the one item of bad news is that I have to save up first. It'll take me about three months to save for the scope and then at least 8 to save for a mirror so this won't be up and running for the best part of a year yet, unless I get lucky in the wallet department. exciting! I've wanted a large scope ever since I became a deep sky observer the best part of 20 years ago, so this will be an ambition come true.

I'm planning to spend the weekend putting the finishing touches to the shed. Then I need to put the castors on my 12" scope's base so I can roll it in and out then we're in business!

There's no sign of the weather clearing up. It's typical unsettled English summer weather. I hope it clears up in August, so I can catch the Sagittarius and Ophiuchus summer goodies before they vanish into the twilight.

Oh, and I got my monitor back on Monday. Only it's not my monitor, it's a replacement, which is good as it's a brand-new machine and unlikely to go wrong - I hope. At least PC World eventually got it sorted for me after first trying to fob me off with this 'You have a contract with the manufacturer, not us' crap - they need to read the Sale of Goods Act, especially this bit. Stuff less than a year old should not break, but it does occasionally and the retailer has a responsibility, under the Act, to refund, repair or replace the item and not give the customer the flick with some stupid excuse about 'extended warranties'.
The sketches, I am pleased to say, look fine.

Sunday, 25 July 2010


The new shed is now in place. We started putting it up yesterday and after six hours, a lot of swearing and a few 'teddies chucked out of prams' (patience is not one of my strong points; fortunately the neighbours appeared to be out and thus, hopefully, did not hear an 'f-word-every-other-word' rant at one stage in the proceedings!) it was just about finished with only a few finishing touches to be added. I did make a couple of cock ups but it seems largely straight, secure and solid so I don't think it'll blow down in a gale. It also appears to keep the rain out. There was a thundery downpour this morning and, apart from rain coming in the windows as I hadn't installed them, it looked to be bone dry with the sole exception of one side which let in a few drops in at floor level. I'll get some sealant and sort that out. The real test will come when the autumn and winter set in and we get howling gales and driving rain. I am going to leave it for a while before I put my scope in it to see how it fares, that'll let me see what needs doing to keep any weather out. I went to a party last night and a friend told me that any flat pack assemble-it-yourself item comes with free swear words, the amount of which directly correlates to the nature of the item and the annoyance factor of putting it up; i.e. kitchen units come with 100 free swear words, a shed like mine comes with about 100,000 while a greenhouse comes with several million!
I put the windows in this afternoon, unlike the rest of the thing there were no annoying mini-crises to put up with!

I have not done any serious observing for a while, apart from a couple of mini-sessions with the refractor on a couple of evenings two weeks back. This is because the weather is so highly variable at the moment and evenings which start off clear are not staying that way. We are having a very unsettled summer, apart from a hot couple of weeks in late June/early July. I did manage to sketch a couple of Messiers, just to keep my hand in, while cloud-dodging.

M8, the Lagoon Nebula in Sagittarius. 3.5" refractor at 36x

M27, the Dumbell Nebula in Vulpecula. 3.5" refractor at 36x.

I have no idea what these sketches look like on most people's monitors. My 20" widescreen monitor went bang just over a week ago so I took it back to PC World (who did not want to know, despite the monitor being well under a year old, so I had to resort to playing the arsey customer which, to be honest, I hate doing. I've worked in retail myself - it sucks) and am waiting for the repaired monitor or a replacement. In the meantime I am using an elderly borrowed 17" square matte flat screen job which isn't that good for picture editing or viewing. The sketches look appalling on this one, I am hoping that they look a lot better elsewhere!

I also aimed my 400mm Canon telephoto lens at the Moon the other evening - yes, you did read that right. The Moon. Not only that, it meant I was doing some astronomical imaging - the shame. ;-D
Here's the result of that. I was quite pleased with it, especially as I was handholding the lens at 400 ISO and using a shutter speed of 1/320 sec at f/5.6. I sent a copy to my friend, the well-known author and astro-imager Robert Reeves, who sent me some feedback.
No, I am not going to become an imager, but I do like taking the odd shot now and then. It shows how desperate one can get to do something astronomical!

I have decided that I won't mess around getting a 16" Lightbridge. I do want a decent scope of 18 or 20 inches, so I will carry on saving and get a custom-built, quality Dob. One route, and one that I am currently investigating, is to buy an existing Dob chassis and get the optics to fit. I know someone who has a lovely one (a 20") for sale, minus the optics. However, I'd need an f/3.7 mirror and secondary to fit it as buying a more common f/4 or f/5 would involve a bit of a rebuild, something I don't want to get into. If I can't easily get hold of an f/3.7 mirror for a reasonable price (i.e. comparable to that of an f/4) then I'll probably revert back to Plan A, which is buy a custom-made dob.

Thursday, 15 July 2010

From the notebooks 2 - Obscure Planetaries from Australia

Here are some more sketches from that 1997 trip Down Under. These are some of the more obscure planetary nebulae I observed on that trip. All of these sketches were made at the 1997 Queensland Astrofest at Lions Camp Duckadang, Linville, Queensland on 25/26th and 26/27th August 1997. The scope I used was a 20 inch Dobsonian.

Henize 2-111, Centaurus

Henize 2-141, Norma

Henize 2-207, Ara

Longmore 16, Scorpius

Menzel 1 (PK 322-2.1), Norma
Shapley 1 (PK 329+02.1), Norma

PK 322-5.1, Triangulum Australe

The observatory is still not up yet. That is because our weather has gone completely to pot and is now more like that of October than it is of mid-July. There are gale-force winds, low temperatures (17C/63F) and rain. Plenty of rain. This will please the miserable buggers who have moaned about the heat and lack of rain and who have now got their own way but I hate this crap and want summer back as soon as possible. Apart from anything else, there's no observing to be had but even before the weather completely broke up we'd been stuck in a cycle of clear afternoons and cloudy nights for a couple of weeks.

I might have to rethink getting a big scope. I have not yet been able to find a permanent full-time job and the agency work has completely dried up, although I have some part-time seasonal work delivering tourist guides. I have an interview in two weeks' time for a part-time data-entry job which offers just over £6000 ($9000) and if I get that, which won't be enough on its own, I could at least combine it with the seasonal work. Unfortunately this seasonal job only lasts for the duration of the holiday season before dropping back to a few hours a week.
A 16" Meade Lightbridge, at +/- £1800 is not beyond my financial reach on part-time/low wages but a custom-built scope at just over £3100 is, as things stand. Maybe I should just get a LB and then go for a custom-built David Lukehurst Dob when/if my work and financial situation improves? LB's aren't bad scopes with a bit of tweaking, although their mirror boxes are incredibly heavy for the size of the scope. Hopefully, though, by the time I have managed to put away £1.8K things might have improved.

Thursday, 8 July 2010

From the notebooks - Australia 1997

I was going through old observing note books to scan in my sketches for my new website and I came across some from my observing trip to Australia in 1997. Those brought back some exciting and magical memories! I have decided to share some of the best ones here, as well as in their categories on my web site.
Click each image for a larger view.

NGC 5139, the great Omega Centauri. This 'King of the Globular Clusters' can be seen from southern Europe and the southern United States but has to be seen from the Southern Hemisphere in order to appreciate it in its full glory.
I looked at this wherever I went during both trips Downunder, from South America and also each time I have gone far enough south in the Northern Hemisphere to see it.
It's huge, slightly elliptical and has a curious footprint-shaped area of less star density or obscuring dust, just off-centre. Spectacular.

8" Cassegrain at 72x, Manly, Brisbane, Qld, Australia
August 11th, 1997

NGC 4755, the Jewel Box cluster in Crux.
This is my favourite star cluster, shaped like a capital 'A' and made up of blue and white stars of varying brightnesses but with a conspicuous red giant at the centre.

8" Celestron SCT, Alice Springs, NT, Australia
July 21st, 1997

NGC 6822, galaxy in Sagittarius. This is Barnard's Galaxy, a faint dwarf galaxy. The galaxy was a faint elliptical glow, quite faint against the background sky. Elongated 2:1 north-south with no central brightening.

20" Dobsonian at 60x. Lions Camp Duckadang, Linville, Qld, Australia
August 26th 1997

NGC 55, galaxy in Sculptor.
At -39 S, this is too low to be seen from England, even from the IW (our theoretical cut off is -40 but with atmospheric extinction, not a chance). Huge elongated galaxy with a very bright, mottled core. Only just fits into field of view at 120x.

12.5" Dall-Kirkham Cassegrain
Ellesmere, Qld, Australia
August 3rd 1997

NGC 7293, the Helix Nebula in Aquarius
I made two separate observations of this. One was from a rural site, the other from an urban one. Needless to say, I saw the nebula without an OIII filter more easily from the countryside than I did with a filter from the suburbs of Brisbane, where it was invisible. It was also 1st quarter Moon when I saw it in the suburbs.
Very large, oval ring with a low surface brightness and diffuse outer edges. No central star seen. Drawing made at the suburban site.
8" Cassegrain at 72x, Manly, Brisbane, Qld, Australia
August 11th, 1997

Monday, 5 July 2010

Some sketches from TSP

I have finally got round to scanning in various sketches, as I was doing a rebuild of my website and needed to scan pictures for it. Among these are some of the pics from this year's Texas Star Party. Click on each sketch for a larger image.

NGC 3245A, Leo Minor
Observed with Dennis Beckley's 18" Obsession at 258x.
Very thin and very faint. Pops into view with averted vision. Evenly bright throughout.
Prude Ranch, Ft. Davis, TX, USA

NGC 3279, Leo
18" Obsession, 258x
Bright, very thin, elongated.
Prude Ranch, Ft. Davis, TX, USA

NGC 3432,Leo Minor
18" Obsession, 258x
Very thin, irregular. Mottled, elongated centre.
Prude Ranch, Ft. Davis, TX, USA

NGC 5394 and 5395 (Arp 84), Canes Venatici.
48" Dobsonian
Very large and bright through the 48". Full of detail. 5395 is the larger of the two galaxies and is interacting with neighbour 5394. There is a bridge connecting the two galaxies. There is distortion in the spiral arms of 5395.
The Lowrey Observatory, Ft. Davis, TX, USA

NGC 3242, Hydra.
48" Dobsonian, 814x.
This is, like all eye candies, pretty nice in more modest apertures but is absolutely sensational in the eyepiece of 'Barbarella'. There are two green rings, the inner ring is more oval than the outer one and is thickened at each end while the outer one has a furry appearance. The central star is bright. Between the rings is 'gauzy' looking nebulosity which has a tinge of pink to it and the whole p.n. looks three-dimensional. I try not to write 'wow' in observing descriptions, As they say. Fabulous!
The Lowrey Observatory, Ft. Davis, TX, USA

NGC 4038 and 4039, Corvus
36" f/5 Obsession Dobsonian, 352x.
Very large and bright at 352x in the 36".
NGC 4038 is the thinner (uppermost in sketch) of the two galaxies. It is elongated and distorted with a brighter, mottled centre. NGC 4039 is fatter and not so elongated. It has bright HII regions and is very mottled. I can see 4039's tidal tail easily but 4038's is fainter and does not show up in the scan, although it is in the original sketch.
Prude Ranch, Ft. Davis, TX, USA

By the way, my website has been added to, with Messier galaxies the first observations up. Click here to visit the site.
I am getting itchy feet and am longing to visit Australia, or somewhere else south of the Equator, to see southern goodies again. Last year's visit Downunder wasn't the best for astronomy, although I wasn't actually on an astronomy trip, with the single opportunity I got for some serious observing washed out by storms and torrential rain during Australia's wettest and windiest winter for 25 years! However, any potential trips will have to wait until at least the end of 2011 as I want to get that 18" scope first!

Sunday, 4 July 2010

Fourth of July

Firstly, I would like to wish my American friends a very happy Fourth of July! I hope you all have a great day. :-)

It was clear last night but, as it's only the beginning of July, it still isn't 100% dark, so I didn't take the 12 inch outside (although once the shed's up and the scope installed, that will change as I won't have the effort of lugging it in and out of my room) but I did do a quick binocular session.
My first interesting object - two objects in fact - wasn't a natural celestial body but the International Space Station, at 2300 BST (2200 UT). The ISS flight path takes it over here and you see it about every 90 minutes on a clear night, not much of a big deal these days as it's familiar enough. However, in front of the ISS was a smaller, fainter, satellite on the same course and moving at the same speed. I knew it wasn't the Shuttle, as none are in space at the moment (and soon, sadly, none will be ever again :-( ) so I did wonder what it was, until I remembered an item I'd seen on the BBC News website earlier in the day about the Russian Progress cargo ship which was supposed to dock with the ISS but which had malfunctioned. Progress had overtaken the ISS while the mission controllers were working out how to fix the problem. I asked about it on Facebook and, apparently, it was Progress I saw.

I went back outside later, at midnight, with my 8x42 binoculars and just scanned around once I'd got dark adapted. I just looked for Messier objects and I saw M81, M82, M4, M22, M16, M17, M20, M8, M103, M11, M39, M10, M12 and M24. Ok, I know it's not exactly hard core deep sky observing, but it'll do me for now until observing can properly begin again later in the month.

In Astronomy Now last month it was stated that M7 is not visible from the United Kingdom. That may be true further north but not true on the Isle of Wight. I can't see it from the back garden here because of a low hill with trees on the top of it about quarter of a mile away (last night, I stood on a garden chair to see if I could spot M7 in between the trees on the hill but without success) but, at -34 declination it is certainly visible, if a little murky from being so low down, from the island. I have seen it from the Vectis AS observatory site just down the road and I have seen it from the Military Road. So, yes, it is visible from the UK.

The new 'observatory' is finally under way. At left is the miniscule progress so far. With help - I have a dodgy back and worse knees and my aunt has arthritis! - this should be done this week and the shed assembled.