Archive for the 'Observing Reports' Category

Observing Report 22nd May 2010 (More Moon bits)

Posted by on May 27th 2010 in Astrostuff, Observing Reports, Pics

The skies on Saturday evening were very clear but after the high temperatures of the day the seeing was only middling. I managed to get some dSLR pics of open cluster M29 and of globular cluster M56, these will need some careful processing for which I've yet to find the time. I did get plenty of good views and camera footage of some lunar features, and I've had time to do some preliminary processing of them, the resulting images are as follows (mouseover for the occasional annotated versions):

Gambart (15 miles dia.), the Fra Mauro Highlands and the Apollo 14 landing site

 Plato (61 miles dia.)

Reinhold (29 miles dia.)

Copernicus (56 miles dia.)

Clavius (136 miles dia.)

Tycho (52 miles dia.)

Bullialdus (37 miles dia.)

Anaxagoras (31 miles dia.)

Scoresby (34 miles dia.)

Just in case you don't know your way around up there, here's some help:

Observing Report 22nd April 2010 (More Moon bits)

Posted by on April 25th 2010 in Astrostuff, Observing Reports, Pics

The skies on Thursday evening weren't the clearest I'd ever seen, there being a light haze obscuring the stars. The Moon, however, was reasonably clear, and with the seeing being fairly good I decided to do a bit of crater-spotting. In order to get a good look before the target went out of the field of view of the scope, I had to start before the sun went down, but that didn't seem to be an issue.

During the unusually short session I managed to see and image quite a few features, following is a small selection of what was on offer (mouseover for the occasional annotated versions).

Rupes Recta (Straight Wall) (67 miles long)
FOV approx 256 x 196 miles

 Rima Hyginus (133 miles long)
FOV approx 275 x 185 miles

Timocharis (21 miles dia.)
FOV approx 113 x 82 miles

Eratosthenes (35 miles dia.)
FOV approx 90 x 76 miles

 

Hadley Rille and Apollo 15 landing site
FOV approx 181 x 156 miles

Apollo 16 landing site
FOV approx 146 x 133 miles

Just in case you don't know your way around up there, here's some help:

Observing Report 17th-18th April 2010 (A night with a Wild Thing)

Posted by on April 19th 2010 in Astrostuff, Observing Reports
Tags: ,

With the absence of air-traffic Saturday night was looking good for observing. There was no wind, stable air, clear skies and hardly any sign of the dreaded Icelandic dust. The plan was to have a look for comets, and to see if I could bag one with the camera. A quick look on the CalSky site indicated that Comet 81P/Wild (pronounced Vilt) might be worth a shot. It's a tiny target - currently in the constellation of Virgo, it's low down, quite dim and well beyond the capability of my binoculars - so it was a scope-job. 81P/Wild is quite a significant comet - NASA targeted it for one of their missions - see here and here.

It took me ages to find the target with the 8" Newt even with the GOTO, primarily because the software's datafile for comets is wrong, leading to a huge positional error. Undeterred, I opted for Plan B - I got the comet's true coordinates from CalSky and plugged them into the software, and soon found the required bit of sky. A thorough look through the eyepiece revealed hardly anything, so I ditched that idea and slapped on the D50 at prime-focus with the intent of taking a series of long exposures. I wanted to be taking frames with exposures in the 5-10 minutes range, so I needed to use the other scope and the webcam as an autoguider, but there was no suitably bright and well-positioned guide-star anywhere near the target. Typical. No matter, I'd just have to make do with shorter exposures, but more of them. It wasn't an ideal situation, but it was better than nothing.

After a few hours I'd got what I needed, having taken a series of light and dark frames for the stacking-software to mull over. By that time a haze had started to develop which meant that the session was over. I packed up and started to process the data before heading in for some shut-eye.

So, here are the results:

(Mouseover for the annotated version, click for the biggie)

Comet 81P/Wild (the bluish smudge) in the centre, NGC5493 (a galaxy) to the left of centre, the other labelled items are stars.
53 light and 45 dark frames restricted to 60 second exposure times due to the lack of guiding.
Stacked in DSS and post-processed with PSCS3.

 

Here's a cropped and enhanced version. This is about the best I can get it, no doubt others could do much better with the data:

 

 

I'm quite pleased with that. I don't usually have the patience to deal with the slow pace of imaging the faint fuzzy things up there, but I'm glad that I persisted. If I get another chance, I'll try to get some longer, guided exposures to see how much improvement can be achieved.

Observing Report 11th April 2010 (Venus and Mercury)

Posted by on April 12th 2010 in Astrostuff, Observing Reports
Tags: ,

The two innermost planets have been prominent in the post-sunset western skies for a few weeks, during which time I've had a few good looks at them with binoculars but dodgy weather had prevented me from getting any pics. This evening I took the opportunity to get out with the camera and tripod to bag a few shots. I've not gone through the whole batch yet, but this one's looking favourite:

(Mouseover for the annotated version, click for the biggie)

Venus, Mercury and a few stars. Nikon D50 with 35mm prime, 5s @ F/1.8, ISO 200, taken at 21:13 on 11/04/2010

If the others are any better I'll let you know.

Observing Report 29th-30th January 2010 (Mars just after Opposition)

Posted by on January 31st 2010 in Astrostuff, Observing Reports

The original plan was to observe Mars on the 27th, the night of its closest approach to Earth (the closest approach distance was 0.664 AU (99.33 million km), giving Mars an apparent diameter of 14.105") but the skies were cloudy so the deal was off. Instead, I had to be content with observing just after opposition on the 29th when the skies were nice and clear, the reflected light-pollution was minimal and the seeing was good. The only downside was that the Moon was almost full and visually quite close to Mars, so the sky wasn't as dark as usual. It was damned cold here, but I wasn't about to let the falling temperatures get in the way of seeing Mars at such close quarters.

Before opening the obsy roof I had to put the fan-heater on for a few minutes to warm up the mount as it had been iced-up for a couple of days and it doesn't like starting in the cold (ice in the gears isn't a good thing). After that it was a doddle, except for the frost that formed on everything unheated. The scope was soon pointing at Mars and I cranked-up the new camera.

This time I was trying something different - using RGB filters and a mono camera. This meant grabbing filtered avi data-runs for each of the three colour-channels and another for the luminance-channel... all within a four(ish)-minute period so as to minimise any image-blurring due to Mars' rotation. After a few failed attempts I managed to get the suss on it, and after that the data-sets were quite easy to get, if a tad rushed.

Soon it was time to move on. I had a good look at the Moon but didn't think it merited any camera-work, as the surface-contrast was low due to the face-on illumination. Still, it was fun trying to find the Apollo landing areas. Next time out I might try for some images of them, just for the hell of it.

After an hour indoors to warm up, I went back out and slewed the scope around to Saturn. This time the rings were more open so I grabbed some filtered avi data, but yet again it didn't turn out well due to the planet being so low above the horizon. I'll probably process the data anyway, but if they're crap I'll just bin 'em.

After another hour or so of watching Saturn the temperature had fallen to -7C. The mount was struggling, no doubt due to the cold thickening the grease inside, so I ended the session, closed the obsy roof and put the fan-heater back on to get rid of the ice.

Anyway, this is the result:

Not bad for my first attempt at this method, eh?

Again, you'll have to wait for me to find time to process the Saturn data.

Observing Report 6th January 2010 (hunting far and wide)

Posted by on January 7th 2010 in Astrostuff, Observing Reports
Tags:

And now for something completely different...

Go on, click it, you know you want to!

Orion, snapped on 06/01/2010 @ 21:30 from my back garden - a single 10s NEF exposure @ ISO200, Nikon D50 with 35mm prime @ f/1.8, no filters, fixed tripod and none of the fancy astrogear that's currently out-of-bounds in the iced-over obsy.
Processed with PSCS3 and Noel's Actions, saved as a PNG.
Conditions: average-to-poor seeing, -8C, gentle breeze, low haze with significant light-pollution.

Suffice to say that other than getting some still-to-be-processed pics of Gemini, I didn't do much other observing as it was too damned cold to stay outside.