Doncaster Astronomical Society (UK)

From Copernicus to Kepler

2008-05-22T21:44:00.002+01:00

At 7.30. p.m. prompt on Thursday, 12th June, 2008, member Mr. Colin Maskill will give a talk entitled 'From Copernicus to Kepler'.

Non members welcome, we meet in St. George's House to the rear of St. George's Minster, Doncaster town centre.

M57 The Ring nebula and focusing

2008-05-15T13:33:00.036+01:00

I had to wait until the early hours of this morning to allow time for Lyra to rise high enough above the roof tops, before I could start imaging M57. This was the first period I've had the opportunity to use the 'Auto Focus' facilities that I have gathered together. Here, I mentioned the motorised Feather Touch focuser with its driver this is used with ASCOM compliant software, such as Focus Max or DSLRFocus.

ASCOM is 'Microsoft Windows' only but I use a Mac laptop, so I had to install 'Windows' on my Mac as a virtual machine via VM Fusion.

DSLR Focus connects to the motorised focuser and also to my Canon 10D. I do a rough focus* through the camera and note the digital position indicator on the laptop, via the DSLR Focus software the focuser is then moved outwards slightly.

The software then makes 3 exposures averages them, moves the focuser a predetermined step inwards and takes three more. This it does for 10 iterations, at the end of this action a graph is produced and the optimum focus position is suggested.
All this happens whilst you just sit back and twiddle your thumbs or put the kettle on.

DSLR Focus does all these focus images in JPEG because it downloads quicker via USB to the laptop. Of course, you must remember to switch back to Raw when you are capturing your sub exposures and of course, I didn't!

So this is is the result of 30 x 120 seconds of medium quality JPEGs.

* This rough focus only has to done once, this particular make of focuser is an 'absolute position focuser' so it's possible to put it in the same predetermined position every focus attempt, the software remembers it, even if you don't.

80 mm refractor, Astronomik CLS filter and a standard Canon 10D DSLR.
Aligned and stacked in Nebulosity and finished in Photoshop CS3.

M27 the Dumbbell Nebula

2008-05-14T20:05:00.006+01:00

A clear sky last night but with a half Moon high up, reasonable transparency too, made a change from the recent clear but very hazy skies. This was taken, an easily available old friend welcoming me to the nebulae of summer, at 3.30am, just as dawn was lightening the sky.

Racing against the dawn, I took 7x120sec frames and a dark for a defect map. No flats, knowing the telescope and chip didn't match and I'd have to crop anyway, and such a small target would still leave acres of starry sky around it. I used GradientXTerminator to help even the background.

The telescope was a Skywatcher 80ED riding on and guided by a Meade 14" LX200. The camera was an MX25C. Processed in AA4 and Photoshop 7.

Brian.

M97 The Owl nebula

2008-05-10T12:05:00.019+01:00

I've spent another night on the garden bench imaging the Messier object, M97, otherwise known as the Owl nebula, NGC 3587. It's in Ursa Major and has a magnitude of + 11.2, also close by and in this frame is the edge on spiral galaxy, M108, NGC 3556.

This planetary nebula is a small dim object, this first photograph is a crop of about 25%, on the second I've cropped even closer to give a better view of that open owl face.

The photograph is made up of 50 x 120 seconds subexposures.

80 mm refractor, Astronomik CLS filter, standard Canon 10D DSLR.
Aligned and stacked with Nebulosity and finished in Photoshop CS3.

NGC 7000 The North America nebula

2008-05-08T10:36:00.018+01:00

This is my first attempt at this nebula and I was surprised at the large size it is, this is an APS full frame shot with no cropping, taken with a standard Canon 10D and an 80 mm refractor, the frame covers an area of sky 2.7° x 1.8°. I think that a focal reducer would probably help here -it would also help flatten the field- the nebula would then sit comfortably within the frame, rather than shoe horned as here.

This image is made up of 11 x 120 seconds exposures, it obviously needs a lot more, but I kept falling asleep at the wheel ( well on the garden bench actually ), so I called it a morning, especially as the garden song thrush was starting to warm up for the chorus.

Click on the image for a slightly larger version.

Moon and Mercury

2008-05-07T07:34:00.007+01:00

Having seen on Brian's "whats on" write up that the Moon and Mercury are close on the evening of the 6th of May and a pleasant evening as well I was determined to get a shot or two of the pair setting. Mercury has evaded me quite a few times through cloud etc. So I looked out of my front window and sure enough there they were towards the WNW. I took quite a few pictures from my driveway including this one at 2142 BST.

Taken with my Canon EOS 350D. Tripod mounted for 4s at f9, ISO 200, 55mm lens. Cropped and shopped in Photoshop.

Another view. This time zoomed in....

Taken 5 minutes later. Again with my Canon EOS 350D. Zoom set at 245mm, 3S, ISO 400 at f9. Again cropped and shopped in photoshop.

The sky this month

2008-05-06T18:40:00.004+01:00

We now have another associated link called..... well the title says it all. This will evolve into an information and resources blog, which will enable amateur astronomers to get the most from their observations.
There's also a link for this down the right hand side.

The Vixen VMC260L has arrived

2008-05-04T11:23:00.004+01:00

The first of the new observatory's telescopes has arrived, the Vixen VMC260L which will be used "to take pictures of smaller items, galaxies, Planets, Planetary nebulae, Asteroids etc."

The Observatory's new floor

2008-05-04T08:10:00.011+01:00

Yesterday afternoon a couple of us managed to partially lay the floor inside the new observatory, it took a few hours starting around 1.30 p.m. ish and finishing at 7.00 p.m. after which, we were fed bangers and mash by the local Beaver troop.

The job was to get these rectangular boards into a circular shaped observatory.

The floor can easily be removed for maintenance and access to under floor cables etc. now they've been cut and fitted for size, the next step is to lift them and put in place a damp proof course and insulation.

Panoramic view of the observatory site

2008-05-03T22:10:00.007+01:00

Earlier today, I visited the observatory site and took the opportunity to grab a few exposures to produce this panoramic image.

The camera was fitted to a tripod via a ball and socket head, which has a revolving base and a 360° scale. I took 9 exposure at 10° intervals, using a 16 - 35 mm zoom lens, set at the 28 mm position. To get the camera level, I placed a bubble level in the hot shoe.

Photoshop CS3 was used to combine all the images, I would like to say it took skill and dedication to get this final result, but Photoshop just chugged along and came up with this all on its own.

If you click on the image, you'll get a better view.

More work on the New Dome

2008-04-29T16:30:00.005+01:00

1. As you'll recall it poured down and thundered and did all sorts of things on Sunday the 27th. This served to test the resealing of dome to concrete I'd done the previous day, and it was perfectly dry inside on Monday.
2. The Vixen VMC260L will be delivered tomorrow, I'm told.
3. It arrived as promised and is in my hall.

Continued work on the new dome

2008-04-24T14:16:00.002+01:00

The dome floor dried out and work to seal it was done, but not effectively enough. So the wet parts will have to dry out again and be resealed. It's taking a lot of tubes of the sticky stuff.
The pier, made from 10" Dia. steel piping, is positioned and bolted to the concrete base. It stands 55.5" high, but when the wooden floor is in, the top wil be 48.5" above it. The mount will take the telescopes another 18" higher.
The first of the telescopes has been ordered, a Vixen VMC260L, and its work will be to take pictures of smaller items, galaxies, Planets, Planetary nebulae, Asteroids etc.
A Takahashi FSQ106ED will be used on wider objects, nebulae, star clusters, galaxy clusters etc. A Skywatcher 80ED Pro will be used to fill that function until the Tak is obtained.
The old Meade LX55 6"AR will also sit on the mount and will be fitted with an Hydrogen Alpha filter; the telescope we have, the filter will take a little time.

Brian

The society's new dome goes up

2008-04-13T16:04:00.011+01:00

On Saturday morning members of the society again met at the observatory site to continue with the construction of their new observatory. The captive Sirius dome was released from its shipping crate and slowly pieced together.

"Welcome ..."

Cancer. The Crab

2008-04-09T14:00:00.005+01:00

I took this photograph of Cancer showing M44 on the 7th April at 0256 UT. Using Canon EOS 350D 18 - 55mm lens. 25s at f5.6 1600iso. By comparison to some of the bigger constellations Cancer is pretty small and non-descript with the exception of M44 the Beehive cluster and M67. Cropped and shopped using Photoscape.

The last two evenings

2008-04-08T15:24:00.021+01:00

The last two evenings have been very nice here in Central Texas, in contrast to the thunderstorms that greeted us and the ones forecast for tonight onwards. Very clear and cloud free until about 2200 last night. I have easily been able to identify numerous stars, objects etc. The best so far has probably been M44, the beehive cluster visible to the naked eye and through a pair of 10x50 binoculars stunning, it even got a wow out of my wife! Here are few of the pictures I have took just using a Canon EOS 350D DSLR and tripod on Sunday and Monday evenings.

The picture below is of the constellation Leo with Saturn bright (centre right) and the star cluster Melotte 111 towards the bottom left. Taken at 0241UT, 2141 CDT 06/08/04. 18MM lens at f5.6. ISO 1600. 20 secs. Cropped and shopped in Photoscape freeware.

My next offering is wide angle shot. Taken looking in a WNW direction last night, with the tripod head at approx 45 degrees to the horizon so I could get everything in. From right to left Orion, Taurus, The Pleiades and the one day old Moon setting. Taken at 0145 UT, 2045 CDT 07/04/08. ISO 1600, 15s, 18mm lens at f5.6. Once again shopped in Photoscape.

Star Trails Taken last night. Because I am currently at only 31 deg of latitude Polaris is far closer to the horizon and the shot suffered from quite a bit of light pollution from the city of Waco about 15 miles north. 22 Mins exposure at f5.6 at iso 100. Taken at 0337UT. Shopped in photoscape.

My Last one for today is of the glorious 1 day old Moon last night. Taken at 0125UT. ISO 200 1/4s , at f5.6, 18 - 55mm lens.

The Plough

2008-04-07T18:33:00.006+01:00

The constellation Ursa Major contains the group of stars commonly called the Big Dipper in the USA and in Britain we call it the Plough. The handle of the Plough is the Great Bear's tail and the ploughs cup is the Bear's flank. The Plough is not a constellation itself, but an asterism, which is a distinctive group of stars. The stars Alcor & Mizar can easily be identified in the middle of the the handle. Taken with a Canon EOS 350-D. 20s, 18mm wide angle lens, F5.6. ISO 1600 at 0144UT. 2044CDT from Riesel, TX 06/04/08. Cropped and edited using some HP software available to me at the time.

Galileo's Tomb

2008-04-05T08:13:00.002+01:00

Following our recent holiday in the Med we called at Florence and found the the tomb of the famous scientist and astronomer Galileo in the Santa Croce Church in Florence Italy. Galileo's tomb shows him staring up at the stars.

Regards Dave Hardware

How to motorise a Feather Touch focuser

2008-04-03T17:24:00.011+01:00

My 80 mm refractor is fitted with a Starlight Instruments Feather Touch focuser, this first photograph shows the two speed focusing knob, the inner black knob for course focusing and the outer gold coloured knob has a 10 to 1 reduction for fine focus adjustment.
This works very well for visual astronomy, but when I have to get critical focus with a DSLR attached, the view through the viewfinder is dim and even touching the fine focus knob can make the image bounce.

I therefore decided that Starlight Instruments motorised Feather Touch system was just the thing. A stepper motor replaces both right hand manual focus knobs, this is easily fitted by the end user.

I purchased a DSM-1 motor attachment and DH-1 hub which allows the focuser to be remotely operated by a computer. To operate the focuser from the telescope position for visual work, I obtained the DHC-1 Hand controller, which has a digital display, one click of either button moves the focuser in or out, 3 microns at a time, but keeping a button depressed, moves it in one smooth continuous movement.

The build quality is excellent and the three parts are made from anodised aluminium and compliments the Feather Touch focuser. There are no UK agents, therefore I had to deal directly with Starlight Instruments and import the equipment directly from the USA myself.

The Leo Triplet

2008-03-31T14:52:00.007+01:00

Last night I had a go at the Leo Triplet, the sky wasn't totally clear, clouds were about and sometimes I was shooting through the gaps, however, I did get some clear sky for a time.

I actually took 50 x 120 exposures but had to discard 11 due to cloud getting in the way. Tonight for the first time I have a USB link between my DSLR and the laptop, which worked! I could check the focus on the screen rather than the back of the DSLR. I'm still having to go out to the camera though to tweak the focus knobs, but in the very near future I'm hoping even that can be done remotely.

At 1.30 am I called it a night the clouds were getting too thick here, so I had an early night.

39 x 120 seconds exposure. 25 x 120 seconds Dark frames and 20 Flat frames.
80 mm refractor, Canon 10D DSLR and an Astronomik CLS filter. Stacked and aligned in Nebulosity, finished in Photoshop CS3 also using Noel's Actions.

A start to the society's new observatory

2008-03-29T09:00:00.003Z

Yesterday morning a number of society members gathered at the observatory site to lay the concrete base for the new Sirius Observatory that arrived from Australia a few weeks ago.

Our first dome can be seen in the background with the shipping crate containing the new Sirius dome.

Eddie, Brian, Martin and Malcolm.
Photographs with a Canon 1D Mk2 and a 16 to 35 mm zoom lens.

The Makarian chain region

2008-03-22T17:33:00.027Z

I'm fascinated by photographs that show clusters of distant galaxies, this is, as the title says, the Makarian chain region, part of the Virgo galaxy cluster.

I didn't know what results to expect - well not much really - when I pointed my small refractor with attached DSLR, but this is the resultant image. It does need more exposure, however this one is made up of 31 x 120 seconds exposure.

On this image I've identified a number of the galaxies and from these it should be easy enough for you to identify any of the others. Apparently NGC 4435 and NGC 4438 are known as 'The eyes'

80 mm refractor, Astronomik CLS filter and a standard Canon 10D.
Aligned and stacked in Nebulosity, finished in Photoshop CS3.

M106 in Ursa Major

2008-03-22T12:41:00.003Z

I've tried this before without success so disciplined myself to keep at it for 3 hours, but the haze and my poor processing still failed to get the most out of the data. Just visible are 4 more galaxies, one brighter than the other 3.

The exposure was 35x300sec using the 80ED and H9C with an IDAS LPS filter. I'll try it again sometime with shorter subs and without the filter.

M82 the Cigar galaxy

2008-03-18T22:16:00.002Z

February the 8th '08, a hazy night but this was high up enough to try. The exposure was 10x600 secs, though some more were lost to cloud and thicker haze. The 80ED was used at native 600mm focal length, though I was tempted to add a barlow to increase the image size.
The camera was the SX H9C and guiding was through the 14" Meade LX200 that the 80ED was riding on.
Processing in AA4 and Photoshop 7, not my forte at all. Must practice on that side of the business.

Double Cluster

2008-03-13T08:15:00.006Z

The open star clusters NGC 869 and 884, widely known as the Double Cluster in the constellation of Perseus. I've tried to image this cluster a number of times but never had much success in focusing, but a few nights ago I had another bash and produced this image.

The cluster is over 7000 light years away and looks good through a pair of binoculars.

30 x 120 seconds exposures with a 80 mm refractor, Astronomik CLS filter and a standard Canon 10D. Stacked and aligned in Nebulosity and finished in Photoshop CS3, with Noel's Actions.

Earthshine

2008-03-10T12:34:00.005Z

It was a slender crescent moon last evening, I wanted to show Earthshine . So, I exposed for shadow side of the moon which gave me this resultant image, an aeroplane with flashing lights can be seen approaching the moon from the left.

Canon 1D Mk2 , 300 mm f2.8 lens and 2 x extender. 1 second at f6.3 ISO 400.