NLCs shine over Kendal

The 2014 NLC Season is now at its half way point, and although we’ve missed some because of the weather (same old story, I know) there have been a couple of pretty good displays visible from Kendal, which I managed to get photos of from the Castle. First, a display seen June 19/20th…

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Then we had a display the other night, July 6/7th… which was spectacular from further north, and the east, but from here in Kendal my view was ruined by lingering cloud (which followed the NLC as it drifted east!!)…

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…and I had a fleeting moment of fame when the “Good Morning Britan” weather presenter, Laura Tobin, retweeted one of my pics to all her Followers and recommended my NLC blog page, too…

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Hopefully there are a few more good displays to come between now and the end of the month, but oh, the weather has to buck its ideas up…!!!

NLC activity picking up…

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Hope some of you saw the rather impressive display of noctilucent clouds last Thursday night/Friday morning? I saw it from Kendal Castle (of course!) and took lots of pictures (of course!) but rather than write all that up here, can I ask you to wander over to my blog where there’s a full report? Ta.

http://cumbriansky.wordpress.com/2014/06/20/the-nlc-appear-at-last/

 

The importance of good skies

As mentioned at the last couple of meetings, I’ve been taking every opportunity to catch a photo of comet C/2012K1 (PANSTARRS) making its way across the night sky.  It has brightened to about Magnitude 8 at the moment, but as the nights get shorter around the summer solstice, it becomes harder to photograph a such diffuse object against a dark sky.

Here is my effort from last night (to be precise, early this morning), highlighting several issues that upset good astrophotography.  20 exposures of one minute each, stacked together with the 20 frames aligned on the comet – so the stars appear as short lines because the comet has moved a slight amount from one exposure to the next.

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What are the issues ?

1.  At this time of year, the Sun dips only 12º below the horizon at night.  Full astronomical darkness needs 18º below (which won’t happen again until the 3rd of August), so in astronomical terms the sky isn’t really dark.

2.  The comet is visually only about 60º away from the Moon, which is also above the horizon and more than half illuminated.  The moonlight lightens the background even more than the twilight, making it hard to distinguish the comet tail.

3.  Although the sky looks clear to the eye – and there are no clouds visible – there is a high level of humidity (about 90%).  The humidity catches the moonlight and creates the illusion of streaks across the sky as the telescope mount tracks the movement of the stars.

4.  The comet is now only 25º above the horizon, which means it is being photographed through much more of the Earth’s atmosphere.

Compare the result with an earlier photo, which was processed identically to the above.  This one was taken on the 26th of April in full darkness, with no Moon, 60% humidity and the comet at an elevation of 83º (almost vertically above the observer).

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Even though the comet is a couple of magnitudes fainter, it is much more distinct in the photo.  Dark, clear skies are the key.

Simon

 

Full moon image

Prompted by a full moon photo from our ex-chairman Ken Hough, I thought I’d try something different for me.

As a kid, one of my goals was to take a picture of the Moon when it was full. I think prompted by a picture in Patrick Moore’s ‘Observers Book of Astronomy’ which I read cover to cover. I thought it would be hard and I was right. I failed due to lack of equipment and ability. I knew nothing about photography, especially ‘wet’ film photography. A few years later I took slides but never attempted anything astronomical.

Now, many years later, owning an 8″ Meade SCT, I thought it’d be easy. I was wrong… I found that my 8” gave poor shots using the Canon SLR at prime focus. The 8″ scope was fine with a webcam [stacked etc. with Registax] for small fields of view, but the whole Moon was non-starter. However, with my “little” William Optics ZenithStar 66 Petzval ED Semi-APO  66mm f/6 (400mm focal length) aperture scope, I thought an experiment was worthwhile. Its large field of view would easily encompass the Moon on my Canon EOS 400D and stilI allow short exposures to get round seeing issues.

Last week May 13th, at nearly full moon [phase was 98.9%], I mounted the scope on a wobbly cheap photographic tripod and took a series of images from central Kendal with as fast an exposure as I could – 1/4000th ISO 800  – with the Canon camera at prime focus. I aligned 8 of these in Photoshop, overlaid them and then flattened the resultant, applied an unsharp mask and adjusted the levels to bring out some more detail – what is usually called stretching in astro-image processing. All the grainyness of the original images virtually disappered and I’m pleased with the result. Lots more detail than I’ve ever got before as my previous attempts normally looked washed out and bland. Really pleased.

Moon, phase 99% May 13 2014,  8 images 4000th iso 800 WO 63mm Scope, Canon EOS400D

Moon, phase 99% May 13 2014, 8 images 4000th iso 800 WO 63mm Scope, Canon EOS400D

Ian B

Stargazing and Scarecrows…

Last weekend Stella and I made our annual pilgrimage to the village of Wray for its Scarecrow Festival. “What’s that got to do with astronomy???” I hear you cry. Well, this year we decided to find a place to camp down there, rather than go there and back in a day, and the place we stayed at – Redwell Fisheries – turned out to have a pretty good dark sky, dark enough to enable me to take some pretty good photographs of the stars, and dark enough to set me thinking about a future EAS event – but more of that later…

Here’s where we camped at, Redwell Fisheries… (click on all the following images to enlarge them)

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…and here’s the camping field, with our wee tent…

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The Scarecrow Festival parade was very good, as usual, and by the time we got back to the campsite it was getting dark, with a beautiful crescent Moon (plus Earthshine) and Jupiter sinking down towards the west…

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About an hour later it was dark enough to see actual stars, so Stella and I headed down to the lake which lies at the centre of the site, found a nice dark spit, and I started what turned into a couple of hours of pretty rewarding astrophotography. Here are some of the pics I took – note some of these are composites of several stacked images…

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(That’s CASSIOPEIA, if you couldn’t pick it out)

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Moon with Earthshine…

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The Milky Way above the lake…

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The stars around Deneb

So, a pretty successful “astrophotography safari”, and it did set me wondering about a possible EAS trip there, maybe even for a camping weekend? The site manager said she would be delighted to have us there, and would turn off as many lights as she could to make it as dark as possible for us. The sky is already pretty dark, considering the site’s proximity to Lancaster and Morecambe etc… Here’s where it is on the national Google Earth light pollution map…

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…but that doesn’t really do it justice, trust me. The NW sky was a little bright, but the sweep of the sky from north to south was really very dark, and I’m sure we’d enjoy great views through our telescopes from there if we went. Anyway, just mulling a few ideas over, so I’ll let you know if anything is planned. 🙂