Saturday, April 7, 2018

Blade Runner 2049? No, Crete 2018


The most impressive Saharan dust event in more than a decade here on Crete happened on 22 Mar 2018. As the day progressed the sky went from yellow to deep orange. All photos are taken with daylight whitebalance, and no post-processing has been performed. 

Sunday, April 1, 2018

The Moon with my old digicam

OK, not a planet this time, but our beautiful Moon. It was the first time I tried the raw option for the Moon with my old Canon S80 digital camera (with the CHDK firmware update). The camera was handheld over the eyepiece. By lucky coincidence the camera's objective fits snugly into the 26 mm Meade eyepiece "barrel", so it is quite easy to hold the camera stable. Without the raw shooting mode I get lots of color fringing and softness at the edges of the Moon (from the eyepiece), but this can all be corrected during the raw "development". Not bad for a 12 year old camera. Shot from my terrace on Feb 8, 2017 (probably). 

Jupiter, May 2017

I am falling behind in my updates :-) This was captured almost a year ago; I think from the Ederi hilltop, on May 3rd 2017 (probably). 

Saturday, April 29, 2017

Jupiter and Io

Jupiter with Io disappearing behind the planet, and reappearing from the shadow later. Captured from Juchtas, Crete (~800 m altitude) on 28 April 2017. The "jump" in the animation is from when I relocated from a little below the peak, to the actual peak where the seeing was better. Even just slightly below the peak I could feel an intermittent cold drainage flow, and the telescopic views were blurred as a result.

Monday, May 12, 2014

Saturn at opposition (almost), and Mars

Saturn reached opposition on May 10th, 18:15 UTC. Unfortunately the weather was cloudy at that time. This image was taken the following evening, around 27 hours after opposition. Around opposition the rings brighten quite suddenly and quite a lot; this is because the rings are illuminated from directly behind the observer. This effect is often called the Seeliger effect

From the same evening, my only Mars image so far this year. Pretty unimpressive...

Thursday, March 27, 2014

Returning with Jupiter...

It's been quite a while since my previous post - almost two years. During this time I have only occasionally done some observing. The reasons are many; work, other interests (I have been very interested in calisthenics the last couple of years), being tired of mosquitoes getting into my flat every time I open the door to take out or take in the telescope, being plain old lazy, and simply not finding the same joy as before in astronomy. Nevertheless, I do not intend to let this blog share the fate with so many blogs that die after a few posts. So, for starters, here is an image of Jupiter from some time ago. Captured from Ederi hilltop on 19th March 2014,  1741 UT.

Wednesday, April 18, 2012

Mini-review of Glatter Parallizer

As a planet imager I am obsessed with accurate collimation. One of the many sources of error lies in the lose fit between a 1.25" adapter and the 2" focuser, and lose fit between the 1.25" collimator and the adapter. In the past I would solve this by shimming the adapter (with tape) and the barrel of my laser collimator, making the fit so tight that I had to put the shimmed 1.25" adapter in the freezer to be able to insert it in the 2" focuser tube! That also meant I could not remove the adapter in the field.

My recently aquired Glatter Parallizer has solved my problems. While I have not done any extensive testing, I can tell that it gives me about the same accuracy as I could achieve with my best shimming efforts. What remains of wobble is probably inherent in the focuser and laser collimator. The design is remarkably simple, just an angled setscrew and outer surface that isn't quite round. The "manual" is equally short; just one sentence!