Category: Solar System

Whilst waiting for the sky to darken enough to image M13, I put the webcam on the 9.25 and took a 3 minute video of Saturn against the twilight sky.

I converted the avi file into individual bitmaps using VirtualDub and the then centred the planet in the frame, cropped the image and carried out an initial quality assessment all in one step using Ninox (previously called PPMcentre). Having ordered the frames by quality it is then easy to delete the ones worst affected by atmospheric conditions.

Using Registax, I then stacked the best 300 frames and sharpened the result which is here:

The rings have opened up slightly from their edge-on appearance earlier this year.

With Venus a brilliant object in the early evening sky on Boxing day I put the webcam on the back of the Celestron 9.25″. The ultimate goal is to image the cloud detail on Venus and to this end I’ve aquired a violet filter (Wratten 47) but as this doesn’t block IR I need to piggy-back an IR block filter. Until I obtain one; this is in visible light with an IR-UV block to limit atmospheric dispertion.

A bright moon at the observatory limited deep sky observing so we shot some more footage of Uranus, this time with the recently refurbished 20″ reflector. As this telescope is f/5 a x2 barlow produced a slightly larger image for the same f/10 as the Celestron.

The clouds finally cleared on Saturday evening for long enough to finally get some pictures of the outer planes, Uranus and Neptune. These pictures are really only for completeness. While these planets are gas giants, they’re so far away that they appear tiny through the telescope. The distances in the outer Solar system are truely staggering, Uranus is 19AU away (an AU is the distance form the Earth to the Sun, 93 million miles) or 1.6 billion miles; Neptune, 29AU or 2.7 billion miles. Put another way, the light that the telescope is collecting from Neptune has travelled for 8 hours since leaving the Sun.

Both images were taken using the modified webcam on the Club’s Celestron 9.25″ at f/10.

Another evening photographing Jupiter. This time with the BAS Celestron 9.25″ on the 23rd Jul. Separate red, green and blue avi’s of 45 seconds each were taken, stacked in Registax and then combined in the GIMP (an open source imaging program).

The ’seeing’ was pretty good, but once again, the very low altitude limited the detail in the picture. However, the Great Red Spot is just visible on the right had side of the planet.

Processing a picture taken some 10 minutes earlier shows more of the GRS and comparing the images also reveals the speed that the planet is rotating. This image is in red light only and I’ve flipped it both horizontally and vertically to match convention.

Finally, the opportunity to photograph Jupiter presented itself on a fine Saturday evening. With the current Astronomy Now competition limiting entries to ones produced with telescopes under 4 inches in diameter I decided to try out the BAS 3? Vixen refractor.

Bad seeing curtailed imaging at midnight but I managed to capture a few sequences with red, green & blue filters.  With the planet barely 9 degrees above the horizon, results were never going to be stunning, but some sharpening of a composite image produced the following:

This one is a challenge. It’s very small and it’s always close to the sun (as well as presently being 88 million miles away!). However, as it’s approaching it’s best elongation from the sun for the year, now is the time to take pictures of it.

This one is the result of stacking about 300 frames from a video of about 2000 individual frames. A narrow band Infra-Red (742nm) filter helps to improve the contrast against the evening sky.

A wonderfully clear evening for photographing this conjunction of Mercury and the moon. Taken with a Canon EOS 350D with a 300mm lens.

After the regular Tuesday meeting of the Imaging Group was somewhat washed out the next clear opportunity was Thursday. This composite picture shows Saturn with 5 of it’s moons at 2100 GMT 1-5-2008.

There’s some photoshop trickery here to replace the very overexposed planet with a correctly exposed one.

From the left, the moons are; Titan, Iapetus (very faint), Rhea, Tethys and Dione.