Arwen's meanderings

Hi everyone and welcome to my dinghy cruising blog about my John Welsford designed 'navigator' named Arwen. Built over three years, Arwen was launched in August 2007. She is a standing lug yawl 14' 6" in length. This blog records our dinghy cruising voyages together around the coastal waters of SW England.
Arwen has an associated YouTube channel so visit www.YouTube.com/c/plymouthwelshboy to find our most recent cruises and click subscribe.
On this blog you will find posts about dinghy cruising locations, accounts of our voyages, maintenance tips and 'How to's' ranging from rigging standing lug sails and building galley boxes to using 'anchor buddies' and creating 'pilotage notes'. I hope you find something that inspires you to get out on the water in your boat. Drop us a comment and happy sailing.
Steve and Arwen

Wednesday 13 October 2021

Unable to sail so I divert my attention elsewhere

 With a trailer off the road, a lovely long spell of nice northerly winds and autumnal sunshine and pods of Atlantic porpoise off the Great Mewstone just outside the breakwater, it is very frustrating at the moment. 

Very frustrating indeed. 

So I have taken the opportunity of cloudless night skies to do so more astrophotography down at my local beach, Wembury. 

It is a Bortle 4 sky with the orangery glow of Plymouth light pollution to the north. But over the last few nights I have been blessed with some lovely views of a crescent to half moon, all orangery-pink, low in the sky; so low in fact, it has set by around 10.00 ish pm. Lovely silvery yellow tracks across Wembury Bay. 

My equipment is simple enough

  • a skywatcher discovery 150i WIFI telescope with GOTO mount
  • an ioptron skytracker pro tracking mount
  • an unmodded canon 800D with two kit lenses (18 - 55mm and 55 - 250mm); and then  24mm and  50mm prime lenses
  • a carbon fibre tripod
  • a joby gorillapod
Over the last couple of nights I have been targeting deep space objects on the tracker whilst enjoying wonderful views of Jupiter, Saturn, globular clusters and various nebulae on the telescope. 

Astrophotography is a completely new hobby to me and I only started it six months or so ago.  There have been lots of dark cloudy skies since but below are the efforts from the last two nights. Enjoy. 

This is a shot of the galactic core of our own galaxy, the Milky Way and I was very lucky to get it. The galactic core is now disappearing from our view over winter and there is only an hour or so when you can get a shot of it at this time of year . Even then it is low on the horizon. 
Camera settings: ISO 800, 24mm F/2.8 50 photos at 45" each on ioptron tracker

Our Milky Way galaxy is a barred spiral galaxy and if we could look down on it we would see a central bulge area and four rotating spiral arms out of it. The galactic core is the rotational centre where a black hole exists. We are 26,000 light years away from it. The photos of light hitting my camera sensor on Sunday night started their journey 26,000 light years ago, so the image you see is what the galactic core looked like 26,000 light years ago. 

Our Milky Way has a visible diameter of between 100,000 - 200,0000 light years; contains an estimated 100 - 400 billion stars and at least as many planets. Our solar system travels at 515,000 miles per hour and would take 250 million years to go around the entire Milky Way. 

Andromeda galaxy
ISO 800  at 180mm, F/5.6 50 photos at 50" each
All stacked with dark and bias frames in DeepSkyStacker and then processed using Affinity Photo

and here is the finished processed image
Sadly I have no idea about the fundamental workings of Affinity Photo - it is a steep learning curve even with the textbook and YouTube tutorials so this is my first effort and it does show

Andromeda is the closest spiral galaxy to our own; 200,000 light years across in diameter, it lies 2.5million light years away from us and can be seen as a distant little smudge in the sky just below the constellation Cassiopeia. 

Last night I had a crack at M45 Pleiades otherwise known as 'The Seven Sisters'. It is an open star cluster in the constellation Taurus, containing very hot B-type stars which are blue and luminous. They formed 100 million years ago and the blue reflection nebula around them is thought to be an unrelated dust cloud. 

Photo capture details were ioptron tracker and then 200mm F/5.6 ISO 800 and 40 photos of 50" each. As you can see, my post processing skills are lamentable and progress is slow, but hey, I'm retired...so I have the time to learn eh? 

First effort and I over sharpened things and stretched the image too much

Same data but second processing effort

Same data, third effort. No special effects. 
If you look closely you can just see a slight discolouration outside of the immediate blue. I think there is more data to process there, but I have absolutely no idea how to do that without losing the data I have already processed in the image

Have I said its a steep learning curve is this astrophotography malarkey?
It is almost as dark an art as trying to efficiently set and trim a standing lug sail yawl! 

4 comments:

JP said...

Some great photos! It's been really cloudy recently here so I haven't got the Star Adventurer Pro out for a long time. I'm not sure I've quite got the hang of it quite yet, though it might be I was pushing it too hard with too heavy lenses.

steve said...

Hi JP - if you use facebook - there are several learning astrophotography groups on there and many of them use star adventurers. They'd be a very good source of advice on what lenses to use if that is any help.

How you doing - you well?

JP said...

The skies were clear one evening this week so tried testing the Star Adventurer and it managed to track ok but with lighter lens+camera, 55mm on APSC so only about 80mm. I really want to try the 70-300mm lens so can get some pics of some interesting targets, such as the ones you posted, but the forecast is cloud over the coming week. Oh well, I'm silly busy at work next couple of weeks anyhow, so wouldn't have much free time

steve said...

I can use my dslr with its 250mm lens on the skytracker pro with no effect and get exposures up to a couple of minutes. Weather dependent of course! Hope you get some time away from work. The insanity of 60 hour weeks hasn't escaped me yet - I still wake up in the night occasionally with panic attacks - normally because my brain seems to think I forgot to plan my a level lessons the night before.....five years retired and I still have night panic attacks. Ho Hum!