With the Moon due to occult the Pleiades star cluster, Wednesday evening promised a celestial show like no other. Unfortunately for me the weather had other plans and for most of the day the sky was dominated by a blanket of altostratus cloud that later thinned out somewhat and allowed me a fleeting glimpse of the hazy Moon. It was through these ethereal, episodic breaks in the cloud that I managed the shot above.
Not the most impressive of pictures I have to admit, it’s a 4 second exposure that was shot at 70mm using an f/stop of 8 with an ISO of 100. There’s even a vague hint of a lunar corona in there, but it’s not going win a prize anytime soon. The weather showed no signs of abating and eventually the Moon was completely lost under a relentless carpet of cloud, bringing my very brief session to a close.
Tags: DSLR, Lunar Corona, M45, Moon, The Pleiades, Weather
Posted in Astrophotography | 2 Comments »
It has been a few months since I have tried my hand at another star trail shot, so as Monday night turned to Tuesday morning I decided to head back out and do just that. The temperature was now -8°C and a white, crisp frost had settled on everything, but the sky was so clear it begged believe. The first task was to set the camera up and focus on infinity, which I do by using a distant street light as a reference point. I wanted to capture the sweeping circular motion of the stars, so I aimed the camera on the tail of Ursa Major, made some final setting checks and framed the shot. As a last precaution I ran some test shots just to make sure that I was focused on infinity. With everything checking out okay I began snapping off exposures.
The resulting image that you can see above is a combination of 43×30 second exposures taken at 18mm using an f/stop of 4.5 with an ISO of 400. I had planned on taking 60 exposures in an effort to lengthen the trails, but unfortunately some altocumulus clouds decided to drift into my field of view from the north west as I was nearing exposure number 50. This meant that some of the shots were “spoiled” and had to be dropped at the processing stage.
As star trail images go it’s not great, but it’s not too bad either. What I really need to do is figure out how I can set the camera to take continuous 30 second exposures without having to manually hit the remote switch. This would mean I could get more exposures as well as spend some of the time observing while the camera does it’s thing. Finding a simple solution to this problem would definitely take the stress out of my star trail sessions but until then I’ll have to continue with my method of manually exposing shots.
Tags: DSLR, Star Trails, Ursa Major
Posted in Astrophotography | 3 Comments »
Since RevAaron over at Caffeinated Astronomy began following comet C/2007 N3 (Lulin), his observations and reports have inspired me to spend a little time doing some comet hunting of my own. While comet Lulin skims the dawn horizon and remains (for me) an elusive object, comet 144P/Kushida is well placed for extended observing. Riding high up in the constellation of Taurus, comet Kushida currently has a magnitude of around 10.7 and promises to rapidly brighten as it climbs towards perihelion at the end of January.
With clear skies on Monday night I set up my 25×100 binoculars and began my run at Kushida from 21:30 UT onwards. It was easy enough to locate the position of the comet using a finder chart but it was another thing actually gleaning any substantial detail from it. Sky conditions were excellent - transparency was good as was the seeing but the glare from the waxing gibbous Moon really impinged on my observation and all but washed Kushida away.
Using averted vision I believe I was able to just discern the extremely faint green/blue smudge of the comet but I was not entirely trusting of my own vision. Undeterred by the Moon light I persevered with my hunt for 144P/Kushida but after a further 45 minutes of continued scrutiny I gave in to the futility of my search and called it quits at about 10:20 UT.
While the results of my observation were very ambiguous, it was a good chance to lay the groundwork for further observations that I plan to undertake in the coming weeks (weather permitting). Hopefully with a little luck I can catch a good concrete sighting of this comet as it reaches perihelion towards the end of the month.
Tags: 144P/Kushida, C/2007 N3 Lulin, Comet, Strathspey 25x100, Taurus
Posted in Observing | 1 Comment »
December the 31st: the last day of 2008 proved to be an exceptionally good one where the weather was concerned. With little more than some cirrostratus clouds drifting high up in the atmosphere there was nothing to stop me from setting up the gear and grabbing some photographs of the Moon, Venus and possibly Neptune.
As I was snapping off exposures a jet plane slipped into my field of view and helped add a little interest to the picture above. This was a 1/20 sec RAW mode shot that was taken using a focal length of 70mm and an f/stop of 5.6 with the white balance set to shaded. While this was a fairly straightforward shot, trying to catch even the smallest glimpse of Neptune meant allowing Sunset to turn to dusk, but this would bring it’s own problems. With a magnitude of about 8, Neptune is a fairly dim planet and in order to successfully capture a shot of it a longer exposure would be required, but not so long that the Moon would become blown.
Trying various exposure timings I found that 2 seconds was all the camera could manage before the bright crescent Moon began to flare. Unfortunately 2 seconds just wasn’t adequate enough to hook a shot with Neptune in it, but as a consolation I managed to bag two stars in the constellation Capricornus: Deneb Algedi, a quaternary star system and Nashira, a giant blue/white type A star. The final picture above was taken in RAW mode at 70mm using an f/stop of 5.6 and an ISO of 100 with the white balance set to daylight. Although It’s a decent enough shot it’s frustrating to think that I almost had this sewn up and it would have been nice to end 2008 with a great picture of the Moon, Venus and Neptune, but as the saying goes you win some, you lose some.
Tags: Capricornus, Deneb Algedi, DSLR, Moon, Nashira, Neptune, Venus, Weather
Posted in Astrophotography | 4 Comments »
