Posts tagged “double cluster

Another one of those mixed Astro-photography nights

Ah, the dark nights are coming and for once I’m over the moon about it. Dark nights and colder days mean longer dark clear nights with means longer to check out the celestial displays above. I’d always viewed the summer nights are preparation for the winter when I’d really be able to get into the astro-photography and after what seems like the worst summer in living memory it’s just about upon us.

For once Edinburgh had a rare happening. A weekend night with a clear sky. Normally the sky clears when I’ve got to be up at half 6 in the morning so it was nice to see it on a Saturday night for a change. So, out went the scope about 9.15 to cool down, this time, I was going to do everything right.

I even had a go at EQ aligning the NexStar SE5. This telescope has a built in basic wedge (I mean really basic but it’s better than not having one!). The alignment process seemed like something from the Krypton Factor but thanks to this blog (http://astroadventures.wordpress.com/) I found I was able to figure it out and it’s not really that hard!

So, with scope levelled, aligned and the precise GOTO working while the sky was getting darker I let my nephew play about with the skytour on the handset, you have to encourage potential young astronomers don’t you?

Encourage maybe but little did I realise what the half hour of near constant slewing of the scope was about to do. All was well until we homed in on M57, the Ring Nebula. There it was nice and clear. Camera onto the visual back, couple of shortish exposures to get the focus and all was good. Started ramping up the exposure times with the D7000 tethered to my MacBook, even better I was getting 30s exposures with no trailing and loads of stars so I set the MacBook to keep taking shots and walked away and left it.

5 shots in I noticed a problem. Those nice stars were more like lines, not just elongated stars, lines! What the hell? Figuring a possible alignment issue I realigned the scope and pointed towards the Double Cluster in Perseus. Same problem. So, I flattened out the wedge and aligned in Alt-Az mode, same problem.

At this point I was getting irate. Nasty words were floating around in the dark and the telescopes parentage was being questioned. With not a lot else to try I ran the mains power out to the scope and plugged into that instead of my Maplin’s power tank and guess what? Yes, everything was fine. So I’d undone my EQ align for nothing, it was down to my crap cheap power tank being ran down with constant slewing with the skytour earlier.

With proper power restored, I managed to get 20s exposures in Alt-Az mode on the Double Cluster and also had another go at Jupiter once I cleared the neighbours tree. Jupiter was a revelation, last time I tried it on the webcam it was a disaster, and this time I could actually see banding on the planet on the capture programme. I didn’t get many shots at it until the not forecast clouds rolled in. I’m sure the met office had a random weather selector, their forecasts seems to have little in common with the weather in the real world.

By this time it was near 1am so I packed up figuring the clouds would hang about all night. An hour later I’m back in the garden taking the dog for a piddle and guess what, a fantastically clear night again. Typical.

Still, I’m reasonably pleased with the modest haul of shots I got, certainly one of my better nights to date.

Jupiter, top shot is 2 AVI captures processed at merged to show the planet and the moons. Bottom is a 2x Barlow AVI capture of just the planet.

Jupiter x2

Double Cluster, I’ve added some diffraction spikes to this one in Photoshop, not sure about the effect but I think I like it.

Double Cluster in Perseus w:spikes

The Ring Nebula, just a single RAW in the end but pleased at how clear the nebula is!

Ring Nebula 8 September 2012


Astro-photography success at last?

Who’d have thought that within a week of buying a new telescope I’d have had 3 clear nights to try it out? It’s almost unheard of, especially in Scotland this year but not being one to miss a decent chance out came the new Celestron NexStar 5SE.

First impressions of this little scope are it’s incredibly well built. Everything about it is solid and the tripod it comes on isn’t a million miles away from the EQ5 I had previously, it’s even got a basic built in wedge. The Alt-Az mount is very different however and must be powered up to use, once you get used to it though it’s pretty easy to use and the GOTO is pretty accurate as long as you take time to align it properly.

First night out I made a schoolboy error and didn’t use a dew shield, the result was a dewed up scope once I had it aligned and ready to take a pic or 2. A roll of thin camping mat and some Velcro has done wonders to address that particular issue!

2nd night out was more about getting a decent alignment and trying to get at least one usable shot. Aligning the scope is easy enough. I’ve not managed to get the SkyAlign 3 star method to work yet but the Auto-2 star works fine and if I sync with another 3rd star it seems pretty accurate, in as much as I can see objects in the field of view if not dead in the centre of the 25mm supplied eyepiece.

One thing I have noticed is that placing the wedge hinge (even if you are not using it) facing north and making the mount totally level really pays off and it worth taking time to setup properly.

Using Artucus and Altair as the alignment stars and then syncing with Vega seems to work fine and since these 3 are visible in the twilight it lets me get setup for the fainter objects in good time.

From the first attempts at photography the real pain I discovered was finding the focus point with the camera. It’s a fair bit away from the focus point with the 25mm eyepiece and unless there’s a really bright star in the field of view you won’t be able to focus through the viewfinder. The solution is to use a really bright star and focus with the eyepiece. Switching to the camera you can note which direction to focus and how many turns it takes to get there with the camera. For the 5se, around 1 full turn right is the starting point and from there you can fine tune.

First target of night 3 was the Double Cluster, Caldwell 14 in Perseus. This looks great in the eyepiece and the stars are nice and bright so it was a good first target. Alignment was reasonable and I was able to stretch exposures to about 8s with no star trailing. The end result showed a lot of stars and some nice colours in the stars too. I’ve not attempted stacking yet so these are all single shots in RAW and processed in Photoshop.

Double Cluster, Caldwell 14 8 August 2012

Next target was the Great Globular Cluster in Hercules, or M13. In the eyepiece M13 is just a grey fuzzy patch and there’s not a lot of bright stars around it so I had to go with the one turn right method of focus and fine tune from there. It took a good few goes but I got a reasonable result, which I’m pretty happy with for a first attempt.

M13 Hercules Cluster 8 August 2012

The next target I tried was the Ring Nebula. This was visible in the viewfinder using averted vision but very faint. As it was nearly straight up though there wasn’t enough room to fit the camera on the scope with the mount base being in the way so that’ll have to wait for another night when it’s better placed.

Next target was the Andromeda Galaxy. I was biting off more than I could chew here and the result shows. We’ll try that one again in the winter nights!

Andromeda Galaxy

I ended the night up on the Moon as it rose about the houses around midnight and considering it was behind thin cloud the result was pretty good.

Moon 9 August 2012

All in though, a pretty good night and I made more progress with the NexStar 5se in 2 nights than I made with the 200P/EQ5 in 4 months which has to be good. As an aside I should also point out that this is what a rank beginner can achieve with a modest investment in a light polluted area.

If that’s not enough to spur you into giving it a go, while out last night on what was a warm and still night I also caught sight of the International Space Station twice and at least 8 meteors from the Perisids which peak this weekend.

Space quite simply, is awesome!