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Archive for March, 2008

The Sun today – large prominence on SW limb

March 30, 2008 Leave a comment

There’s a nice large loop prominence on the south west limb today. I obtained a few images at 12.00 UT and these show quite a bit of detail in the loop together with the sunspot active regions 987 and 988. Filaments seem to be scarce today and the large diagonal filament which was seen south of 987 and 988 for most of last week seems to have faded completely. Nikon Coolpix 4500 afocal, ISO 100, 25mm wide and 9mm EP’s, PST.

Categories: Solar

Three active regions on the sun – 987, 988, 989

March 27, 2008 Leave a comment

We now have three active regions on the sun with associated sunspots and filaments. From right to left (east to west) you can see 989, 988 under the long diagonal filament and 987. Prominences are small at the moment, you can just make out four on the lower right of the disk.

Categories: Solar

H-Alpha Art!

March 27, 2008 1 comment

I got back from work too late to catch the sunspots yesterday, but I managed to take a few images of the sun as it was setting behind a hill almost a mile away. The effect of the silhouetted trees in front of the sun is quite dramatic and although the sunspots and filaments on the sun are not very clear the whole image is really quite pleasing. The branches of the trees have an almost frosted look to them in stark contrast to the glowing furnace behind them. Here’s the image……..

Categories: Astrophotography, Solar

Active Region 987 appears and its busy!

March 24, 2008 Leave a comment

While photographing the sun yesterday clear areas of plage brightening and sunspot activity were developing on the east limb. Today those areas are clearly visible as active region 987, with active region 988 just chasing it over the limb to the right. The active areas consist of sunspot groups, plage brightening and one long filament arcing across the eastern limb. Observers in the US are reporting some possible flare activity in the bright areas around the main spots. I managed to get some photographs of the active regions at 11.21 and 15.30 UT today with the PST and Coolpix 4500 camera. These images were also accepted by http://www.spaceweather.com/ and a link appears on the front page of that website to my images here http://spaceweather.com/submissions/large_image_popup.php?image_name=Mark-Walters-e-limb-24-3-08_1206361876.jpg

Categories: Solar

Lots of activity on the Sun today!

March 22, 2008 Leave a comment

Well we may be in solar minimum at the moment, but I think somebody forgot to tell the sun about this!! I have neglected to do any sun observations since December 2007 as I have been concentrating more on the deepsky astrophotography, but the Easter break gave me the opportunity to get the Coronado Ha PST 40 mm solarscope and Nikon Coolpix 4500 combo out again. I had read on another forum that someone was having success with better focussing on the 4500 if it was used in macro mode. Although this sounded implausible I wanted to try it out. The sun was a riot of activity around the circumference this afternoon with many fine prominences being visible including a huge arcing example on the southern limb and a nice plasma jet on the eastern limb. And, oh boy, the macro technique sure works!! These are the sharpest focus images I have achieved on the sun so far. Here they are………………..

Categories: Solar

Stellarium 0.9.1 Planetarium Software

March 13, 2008 Leave a comment

This free open-source planetarium software is quite simply stunning. The latest version 0.9.1 came out in January 2008. Previously I had been using Redshift 5, but while trying to locate comets to photograph I was finding the RA and DEC data to be rather inaccurate. The other major limitation of Redshift 5 is that the maximum star magnitude that can be displayed is 14 which often made the verification of photographed comet locations very difficult given that the images usually resolve 15th-16th mag stars.

Having found Cartes du Ciel (also free) to be equally limited in star magnitude unless you download some immense catalogue files I turned to Stellarium and had another look at the downloads available for the programme. To my surprise there were star catalogues (J2000) up to mag 18 readily available in handy compressed files that are just dropped into the main data folder and off you go! As a bonus I also found that bright comet and asteroid data was now available plus some new nebula/galaxy photo textures. With star catalogues loaded up to mag 16 there is no impact on system memory (I have 2Gigs RAM) and some people have reported that the 18 mag catalogue can be used with just 512mb RAM and no obvious system impact! All in all this is shaping up to be one of the best pieces of planetarium software available.

Stellarium oozes quality from the moment you start it up and the startup time takes just 5 seconds now! The night sky looks very realistic and the stars scintillate gently on a black or slightly moonlit background. The foreground is photoreal landscape and can actually be adapted with panorama stitch software to show your own location. There is even an option for some realistic frosty fog at ground level! The controls are all simple to use and the slewing motion to the object of your choice is very smooth and professional. Finding Messier and NGC objects is a breeze with the efficient indexed search function. Nebulae, galaxies and planets have photograph based textures and look superb. All the usual constellation and grid functions are available as well as GoTo control for telescopes via the ASCOM drivers.

Stellarium has now become my first port of call if I want to see what is in the night sky at my location on any given night and build a program of objects to image or observe. If you want to try Stellarium for yourself download it here http://www.stellarium.org/ You will find the Stellarium Wiki here http://www.stellarium.org/wiki/index.php/Main_Page and the Stellarium Forums are here http://sourceforge.net/forum/forum.php?forum_id=278769

Categories: Software

Comet 46P Wirtanen

This comet is currently well placed for telescope viewing and photography lying just to the right of the Pleiades (M45) in the west. It is currently mag 9.5 and fading, but is easily seen in a 4″ or larger telescope with averted vision on a moonless night. It will continue to fade and pass south through Auriga and above Gemini in late March and April. By July it will be Mag 18 and all but invisible to even the largest amateur telescopes. Between March 21st and 31st it will pass through Auriga and very close to a number of the open clusters that abound there and should make for a really nice photo opportunity. Comet 46P Wirtanen takes 5.45 years to complete an orbit of the sun. I photographed it using the Canon 350d attached to the 4.5″ Vixen 115s on the EQ6 mount last night at 10.35pm. You should be able to see a faint green fuzzy ball at the centre of the photo below, that’s the comet! There is a possible small tail to the left of the core.

Categories: Comets