Archive for the 'Astrostuff' Category

Observing Report 21st July 2010 (Sunspots in Active Region 1089 – Session 1)

Posted by on July 22nd 2010 in Astrostuff, Making stuff, New tricks for an old dog, Observing Reports, Pics
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Using some black plastic sheet, some Meccano fasteners, some Superglue, some sticky-tape, a Cornflakes box, a cardboard tube and a pair of Val's old knickers, I constructed a safe solar filter using the some of the Baader AstroSolar Safety Film that I got for my birthday. It fits securely over the front of the C80 refractor:

 

 

OK, so I lied about the box, the cardboard tube and the knickers, it turned out that I didn't really need them :mrgreen:

Anyway, it needed testing properly so I nipped up to the obsy and grabbed some .avi footage of Active Region 1089, where there is an impressive array of sunspots. After processing in K3CCDTools3, Registax and PSCS3, I've ended up with the following two images which are essentially the same except for the application of a little equalization in the second image:

Sunspots in AR1089 (21/07/2010).
100/1000 stacked frames.
DMK mono CCD camera on the C80ED-R.

 As previous but equalized in PSCS3


I'll try to get more footage of this thing over the next few days to see how it changes. I'll probably use a bit of the leftover solar film to make filters for the D50's lenses, and then get some full-disc shots.

BE WARNED: Never view the Sun without a suitable Solar Filter! Solar observing is dangerous and can be hazardous to eyesight and equipment. Don't moan at me when you've burned holes in your retinas, set fire to your person/possessions and/or fried the chip in your camera. Proper solar-observing kit comes with serious safety advice - ignore it at your own peril!

Package 4 – a raci little number

Posted by on July 17th 2010 in Astrostuff, Shiny new kit
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The Celestron straight-through 9x50 finderscope supplied with my 8" Newtonian has served well for a while now but it's always been a neck-twisting operation to actually use it. The eyepiece is just too close to the main scope and it usually ends up in a position where it's awkward to look through it:

The original finderscope

I'd been considering shelling out for a cheap right-angled version but couldn't justify the expense, but then my luck changed - I found a cheap second-hand Orion 9x50 RACI* finderscope for sale on UK Astronomy Buy & Sell.

Setting-up is going to be a much more comfortable affair now that Package 4 has been delivered and its contents installed:

The replacement finderscope

The original finderscope won't go to waste, though - I've fitted it to the 80mm refractor in place of the supplied straight-through 6x30 which I'll keep in the spares box just-in-case.

Sorted 🙂

(* RACI = Right Angled Corrected Image)

Package 1

Posted by on July 11th 2010 in Astrostuff, Making stuff
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You'll recall that during my previous observing session the link between my focuser and my SkyWatcher Auto-Focuser stepper-motor broke. Here's a pic showing the setup, the link is the 2-part ally gubbins that links the drive-shaft of the stepper-motor (on the right) to the shaft of the focus-adjuster (on the left):

Here is a couple of shots of the offending article:

It works in a peculiar way... the small end is attached good and proper to the shaft of the focus-adjuster by means of a grub-screw that clamps onto a flat on the shaft. No problems there. The attachment to the drive-shaft of the motor, however, is rather odd. It works by friction, using an internal O-ring that is compressed around the shaft by screwing together the two parts of the link. It doesn't like changes in temperature (too warm and the O-ring deforms and spins, too cold and it contracts and doesn't grip tightly. Oh, and there's always some flex and hence backlash due to the "flexible" nature of the O-ring/shaft connection. It was destined to fail, and indeed did so.

So, a better-engineered solution was required. Something so simple that a child could use it.

Step forward Package 1. This contained a good-old-fashioned Meccano 4-hole brass coupling:

As supplied, the fit to the focus-adjuster shaft was perfect. The motor drive-shaft, however, has a larger diameter, so I had to run a drill-bit half-way down the coupling to open it up a tad. From then on, fitting it was child's play, using proper screws to attach to the flats on both shafts.

Now it's a good and solid link, just as it should be, with no chance of slippage and no backlash due to the motor torquing itself against any resistance from the focuser.

In short, it's a proper job:

Observing Report 5th-6th July 2010 (A breakdown on the M15)

Posted by on July 7th 2010 in Astrostuff, Observing Reports, Pics
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I got out to my obsy again last night, hoping to get some decent views during the prolonged gaps between regular bands of cloud. Surprisingly, the seeing was quite good considering the day had been hot and the night was still warm. I managed to get some dSLR pics of some Messier objects before the link between my focuser and its motor broke. The breakage meant that I didn't get any dark or flat frames as I was too busy trying (in vain) to cobble together a quick and temporary fix. Nevertheless, I've managed to process out most of the usual spoilers and end up with a reasonable image of M15 (aka NGC 7078), a globular cluster in the constellation Pegasus:

M15 (aka NGC 7078), a globular cluster in the constellation Pegasus.
Subs: 30 light @ 60s, no darks, no flats, ISO200.
D50 and MPCC on the C8N, guided with PHD.

 As previous but with added spikes


The rest of the pics weren't any use so I've chucked them. Besides, I've no time to faff with them anyway - tomorrow I have a focuser to fix.

Observing Report 24th-25th June 2010 (Tidy obsy, scruffy Jupiter)

Posted by on June 25th 2010 in Astrostuff, Observing Reports, Pics
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I managed to get out to the obsy last night, mainly to get the place tidied up and to oust the spiders that had invaded during the spring. The skies weren't really good enough for any deep-sky observing, as there was a persistent high-level moonlit haze that was ruining the contrast and which would have washed-out any images taken with the D50. Nevertheless it was a calm warm night so I stayed up to see Jupiter rise above the eastern horizon into a brightening blue dawn sky.

Not being one to pass up an opportunity, I decided to have a crack at imaging it with the mono DMK camera and some RGB filters even though the seeing wasn't really good enough.

Anyway, the resulting image from the first set of data is below:

 

 

 

 

I've got more data to process, some of which has Europa in the frame as well as Jupiter and Io. If the processing works out OK I'll let you know.

Observing Report 17th June 2010 (Daylight Moon bits)

Posted by on June 22nd 2010 in Astrostuff, Observing Reports, Pics
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Observing the early phases of the Moon from my obsy is a bit of a lottery - due to the restricted western view the only way to get the scope pointing at the thin waxing crescent is when the Moon's high in the sky. At this time of the year, that means observing during the daylight a few hours before sunset, which in turn means that the seeing is always going to be a limiting factor.

Never let it be said that I'm one to shy away from a challenge - here are some images gleaned from webcam data grabbed at about 20:00...

(mouseover the pics for the annotated versions):

Neander (30 miles dia.), Rheita E (40 x 19 miles), Furnerius (76 miles dia.),
Rheita (42 miles dia.), Fraunhofer (35 miles dia.), Metius (53 miles dia.),
Brenner A (19 miles dia.), Young D (27 miles dia.), Fabricius (47 miles dia.),
Vallis Rheita (303 x 18 miles)

 Pitiscus (50 miles dia.), Vlacq (54 miles dia.), Hommel (76 miles dia.),
Rosenberger (58 miles dia.), Nearch (46 miles dia.)

Daniell (18 x 14 miles), Rima G Bond (91 x 2 miles), G Bond (19 miles dia.),
Luther (6 miles dia.), Posidonius (58 miles dia.), Chacornac (31 miles dia.)

Endymion (76 miles dia.), Keldysh (20 miles dia.), Hercules (42 miles dia.),
Atlas (53 miles dia.)

Piccolomini (53 miles dia.), Neander (30 miles dia.), Rothman (25 miles dia.),
Rheita (42 miles dia.), Stiborius (27 miles dia.)

Messala (75 miles dia.), Berosus (45 miles dia.), Bernoulli (29 miles dia.),
Geminus (52 miles dia.), Burckhardt (35 miles dia.), Cleomedes (76 miles dia.)

Madler (17 miles dia.), Theophilus (61 miles dia.), Cyrillus (59 miles dia.),
Beaumont (32 miles dia.), Catharina (61 miles dia.)

 
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