Jupiter Observations – Friday 2 November 2012

Location: Home, Garden , Top of the drive
Conditions: clear, reasonable seeing. Cloudy later.
Equipment: Skywatcher 130, AsdaCam
Highlights: Jupiter

Good clear skies tonight. Jupiter was the first thing I set my sights on and I got so caught up in it that I didn’t move the scope to another target all evening. First of all my notes taken while observing and then the results of the imaging I tried.

21:47 Jupiter seems to be the main prize for tonight. Looking ok in 25mm eyepiece. 2 moons visible. With the 6mm eyepiece signs of banding are showing.
Fitted the RA motor so I’ve got it tracking reasonably well. Occasional dec tweak needed so not perfectly aligned but good enough for me.
I slotted the AsdaCam webcam into the eyepiece socket and shot some AVIs.
Io is supposed to be transiting but I can’t see it. I think I may have seen a notch at the edge of the disk earlier in the 6mm but I can’t be absolutely certain.
Actually, I can see three of the moons. Callisto is visible to N.
According to SkySafari+ the Great Red Spot is meant to be visible – can’t see it visually though.

22:15 The clouds are starting to close in. Rather than pack up though I’m sitting in the garden with the laptop and have set Registax processing the first of the AVIs I shot of Jupiter. I decided I couldn’t wait until later. Also, if I’m doing it wrong I’d rather know now when I have chance to retry than find out later after I’ve packed up and gone in.
So while that processes the clouds have cleared a bit. In between breaks in the cloud I’m writing up these notes.
Meanwhile tried the 6mm barlowed. The disk is huge but not much detail. This cheap and basic barlow does degrade the image.
Cloud settling so making notes now. If it clears I’ll look again. It would be cool to see Io come off the disk.
Tried with moon filter and barlow on 6mm to increase contract. Too much glass in the way now. Barlow off. Hard to tell if moon filter helps. It tones down the brightness but doesn’t help contrast. Tried green wratten 56 filter. Wow that brings out contrast.
I should look into planetary filters. Which colours are best for Jupiter?
Registax has finshed stacking. Had a quick play with the wavelets. Oh wow!!! Got an image with some colour and banding detail. More than I can see visually.
…And the laptop battery dies before could save the test stacking. Not a problem as the source AVIs are safe and now I know the potential is there to pull something from these AVIs. If this patch of cloud doesn’t clear I’m off inside to process them.

22:25. A break in the cloud but not enough to see Io come off the disk. Lets focus instead on the belts.
Northern Equatorial is almost at centre. Can see Southern Equatorial too.
Made a quick sketch. It’ll be interesting to compare with the photos I get from Registax.

22:38. Packing up now. Too much cloud. I’m abandoning the sketch. I think I’m just sketching what I think I saw earlier.

Once inside I had another go at processing my AVIs in Registax. This is a piece of free software that takes a video you’ve shot with a webcam or a series of still frames, finds the best frames and then combines them with some clever processing to bring out more detail. Whilst the workflow is pretty much the same with every image there’s a lot of parameters to choose so on these first attempts it’s a bit trial and error. My first attempt at an image isn’t bad though. It’s clearly Jupiter and it is quite exciting to see this on screen and know that I shot that, in my garden, with a hacked webcam that cost £3 from Asda. It’s 400 million miles away.

I posted the picture to Twitter and Facebook and went to bed, picking up a few positive comments from friends.

I had another go at processing the following day on Saturday. I did a bit of tweaking in Photoshop after to rotate 180° as the image through the scope was inverted. I also resampled it so that it wasn’t so pixelated when enlarged a bit. A further tweak on the contrast brought out the Great Red Spot at the right edge of the Southern Belt. I got excited again at this. I knew it should be there when I was observing visually but couldn’t see it. It’s incredible the extra information you can pull out this way. Think I need to get a better webcam with higher resolution.

The Moon, Observations – Friday 26 October 2012

Location: Home, top and middle of drive.
Conditions: thin cloud, amost full moon.
Equipment: Skywatcher 130, asdacam, 7×15 binoculars
Highlights: Moon, Jupiter

The nights are closing in.  Good news for observing.  Clear early on this evening but by the time I got the scope out and set up about 20:30 it was getting cloudy.  It was OK observing the moon through the cloud although at times there was too much reflection into the clouds causing something of a halo effect that meant there was no definition to be found on the edges. Moon was about 3 days from being full so there was still a terminator.
The crater Bailey was just into the darkness. The rays around Tycho were bright white.
Cloud was moving quite quickly so was variable in thickness. Decided to have a go at imaging so popped a cheap 640 x480 webcam (£3 from Asda) that I’d previously modified, removing the lens and IR filter, into the eyepiece holder.   Shot a few AVIs to try some processing later….
Cloud cover was at about 90% by 22:00 so I packed up. Of course by the time I was taking the last of the kit in, about 20 minutes later it was clearing up again.
Jupiter was just clearing the front gates so I took a quick look through the binoculars.  Looking forward to getting the ‘scope on this and seeing the banding in coming weeks.  Walsall Astro’s What’s Up Newsletter for November helpfully includes transit times for the Galilean Moons and the Great Red Spot (GRS) which I’ve added to the Observation Plans page so I’m looking forward to observing those events.

Summer Triangle Widefield Imaging – First Attempt

At mentioned in my last post, I ended up with 263 frames of the Summer Triangle. I thought I’d have a go at processing one of these to see if I could get more detail out.

So here’s my starting image.

I hadn’t realised quite how bad my light pollution was until I saw this.
It’s a 30 second exposure, sunlight white balance at ISO400 taken on a Canon EOS400D with a Sigma zoom set at it’s widest 18mm focal length.
faintest stars you can see here are about magnitude 4.
I then tweaked it a bit in photoshop, adjusting levels to bring out fainter stars up to about magnitude 7. I removed the colour cast as best I could, although I think I went a bit too at as it’s quite blue now.

Now I know this is far from perfect. It’s a first attempt and I can see quite a few problems.
Stars aren’t quite in focus. I’d focused manually and it’s difficult to know in the dark through the camera eyepiece.
Next time I’ll lock the mirror up to prevent that causing a bit of shake.
Exposure is only 30 seconds but I don’t think I can do longer without the stars blurring with motion. I could, if I put the camera on the telescope’s mount. There is a piggy back mounting screw.
I think I need to really up the ISO, perhaps up to 1600 to captured the fainter stars. I’d held back because I thought I’d end up overexposed with all the light pollution. I think though, that I can fix that with levels in processing.
I need to investigate stacking multiple images too, as that seems to be how many people do it.

Finally I annotated the final image in Skitch on the iPad to identify the various constellations and stars. That was an fun and educational thing to do. I hadn’t noticed the small constellation Delphinus creeping in just below Cygnus for instance, and on zooming in and around the shot, I also noticed Collinder 399, Brocchi’s Cluster aka the Coathanger sneaking in.