Archive

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

Comet 17P Holmes Winter 2007

What a great visual sight this has been over the last winter! Comet 17P Holmes, normally invisible to the naked eye at magnitude +17, suddenly flared up to magnitude +2.5 between October 23-25th 2007 due to a spectacular internal explosion. Suddenly we had what appeared to be a new star in the constellation Perseus close to Mirfak. It was easily naked eye visual and in binoculars, or a small telescope, it appeared as a small white circle with a fainter greyish outer halo. Over the next three months the outer halo expanded enormously so that by the end of December it was much larger than the full moon. For much of November and December it’s shape resembled a huge jellyfish flying through space. It is now fading because it has become so large and diffuse and it is also receding away from us, however a small telescope will still resolve the comet and we should be able to see it for at least two more months. It is currently magnitude 4.5 and will be mag 5.2 by the end of April.

I managed to photograph it on a couple of occasions. The photo below shows the comet left of centre as a creamy white circle in Perseus on 28/10/07. This is more or less what it looked like to the naked eye. Taken with Canon 350d, 2 seconds at ISO 1600 on Alt/Az mount.
Comet-Holmes-location-28-10
On 13/12/07 I photographed Holmes again after it had expanded to the size of the moon and the jellyfish shape can be clearly seen. Canon 350d at prime focus, Equinox ED 80, EQ6 mount, 3 minutes ISO 800……….
holmes-3
Categories: Comets Tags: , ,

Lots of New Toys!

Back in July of last year I decided it was time to get back into amateur astronomy. I joined the British Astronomical Association and took out a substantial loan to buy equipment that would serve all of my developing interests within the subject. Mid Life Crisis ? Well, perhaps, but it was something I had been planning to do for a long time. I considered that I had done the naked eye/binoculars observing apprenticeship and I wanted to be able to see more and further than before. I also wanted to get into the exciting world of astrophotography now that the equipment is relatively affordable and of high quality.

So what equipment did I buy ? Well I had always loved the crispness and contrast of views through a good quality refractor and they require no cooling down time prior to use so I bought a Vixen ED 115s 4.5″ apochromat 890mm (F7.7) as the main imaging/observing scope and a Skywatcher Equinox ED 80 3.1″ apochromat 500mm (F6.25) as a portable imaging and observing scope which could also act as the guidescope for the Vixen when doing autoguided photography.

Knowing that I would get into solar astronomy and recording again I bought a secondhand Coronado Ha PST 40mm solarscope which will let me see prominences, filaments, sunspots and other surface detail.

The mount is a Skywatcher EQ6 SKyScan Pro german equatorial powered by a portable 12v battery power pack.

The imaging cameras include the Atik 16ic mono and an Atik 16HR-C one-shot colour. I also have the Canon 350d dslr which can be mounted on the telescopes.

Other accessories include:

  • Eyepieces: Meade Series 5000 (20mm, 9mm) plus a wonderful WO SWAN 32mm 2″ eyepiece for wide views. Celestron 2X Ultima Barlow.
  • Filters: Astronomik CLS, Ha, OIII, SII, UHC. Baader Solar Continuum. Atik UV/IR Block. Double Variable Polarizing. Aperture Solar Filters (white light)
  • William Optics Dielectric Diagonal
  • Aputure Canon 350d Remote Release/Timer
  • Kendrick DigiFire 7 Dew Heater
  • Celestron Alt/Az tripod for the solarscope
  • Maxim DL and DSLR imaging software
  • Noel’s Photoshop Astronomy Plugins
  • A spare Celestron 12v power pack for the cameras and dew heater
  • A refurbished Toshiba Tecra M3 Laptop
  • Numerous books on the subject!

Phew!

Categories: Equipment

A Return to the Hobby

Well, its pouring with rain and blowing a gale outside so this seemed the right time to start up a diary of my recent return to amateur astronomy after 25 years. Why so long away from the subject ? Well astronomy was never completely ignored over that time and I always kept up with the latest events via astronomy magazines, the news and the internet. I even occasionally made observations with the naked eye or a pair of 10×50 binoculars (I will never forget the joys of seeing Comet Hale Bopp above the house we rented in Montgomery over the Winter of 1996/7, the total solar eclipse of August 1999, the many lunar eclipses and numerous meteors). But somehow the common pressures of life and financial circumstances never permitted me to pursue the hobby in any depth and most of all I lacked a decent telescope!

Where did the interest start? Well of course I saw the first lunar landing on the moon in 1969 on our small black and white TV, but strangely that never seemed to trigger much interest at the time in going outside and observing, perhaps because I was only 5 years old! Much later, it must have been 1977 or 1978, I will never forget the night I was out in the back garden of my parents house near Ponterwyd in mid Wales. Looking north I saw a huge fireball streak across the sky and disappear out over the Irish Sea. It was so large it even produced an audible sonic shock wave as it entered our upper atmosphere. I wasn’t sure what I had seen and wanted to let people know about it so I joined the Society for Popular Astronomy (SPA) and reported it to the Meteor Section. Next month a newsletter came through and my fireball was reported under my own name. I was so excited that I had actually contributed something that I was hooked.

I last used a telescope back in 1982. I had a very basic Tasco 4″ reflector with a few poor quality eyepieces (I am sure some of the lenses were plastic!) , a few filters and a wobbly wooden tripod supporting a manually driven equatorial mount. As lowly as this equipment may have been between 1980 and 1983 that telescope let me see many superb objects including the Moon, Saturn’s rings and Jupiter’s great red spot with a few of the moons of both these planets, Venus, Mars and numerous stars and star clusters. I developed a particular interest in the Sun, perhaps because it changes every day and there is always something new to see on its surface or circumference. I joined the SPA’s Solar Section and by projecting its image onto an old cine projection screen I recorded the changing sunspots and surrounding features, sent the records in and even occasionally got mentioned in the sections newsletter.

I distinctly remember one momentous day which may have ended my observations for good. I had been projecting the sun in the normal way via an eyepiece protected by a glass sun filter screwed into it. I had looked up at the projection screen and was returning to the telescope when I heard a very brief glassy ‘chink’. Looking at the eyepiece sunlight was pouring out of the lens. The solar filter had cracked with the intensity of the focussed sun’s heat!! If I had returned to the eyepiece seconds earlier I might have been totally blinded in the right eye. Of course now it is common knowledge that these cheap glass eyepiece filters are dangerous and should never be used, but back in 1981/2 this was not widely recognised and there were few warnings for the unwary amateur.

After I left home for university the Tasco telescope was sold and developing a career in one of my other main interests, archaeology, took over. In July 2007 I took the plunge and bought some good quality astronomy kit that will last the rest of my lifetime and set off on a new voyage of discovery.

Categories: General