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.

2012K1_20140609_0028_White

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).

2012K1_20140426_2303_White

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

 

More on the Meteor Watch…

It’s now less than a week until a new meteor shower MIGHT light up the pre-dawn sky, so I thought I’d go up to our chosen observing site – the northern end of Scout Scar – and check the place out, and take some pictures which will help those of you unfamiliar with the area to get to the right place late on Friday night.

So… it turns out that Scout Scar is INCREDIBLE!!!! Why did no-one MAKE me go up there and see it before now??? What were you all thinking????? The view from up there is spectacular, a greet sweeping 360 degree panoramic view of Kendal and its surrounding countryside. And the view north will be perfect for viewing whatever happens on Friday night/Saturday morning, so thanks again to Simon White for suggesting that…

bn

Ok… so, here’s where we’re holding our Meteor Watch, after midnight on Friday night…

ss4

…and here’s the car park where you all need park up…

ss5

Aerial views are fine, but don’t tell you what a place looks like from ground level. This is what you will see on the right as you reach the car park entrance…

a

Then you need to cross the road and head for this gate…

20140518_175435

20140518_175507

Then head up this path…

20140518_175524

…until you reach here

20140518_175823

And that’s roughly where we’ll be observing from. There are a couple of benches up there, but I would recommend taking a deck chair or lawn chair up there to rest on while you’re watching the sky.

I should say again here that there is absolutely no guarantee whatsoever that we will see ANYTHING Friday night/Saturday morning. But we are absolutely guaranteed to see nothing if we don’t try. So, I hope you’ll join us if you can.

12th May 2014 – Meeting

The meeting was well attended (around 40 members) and Stuart Atkinson kicked off with a description of his recent observing sessions, and the resulting beautiful photos. EAS members have been searching all round Kendal and the surrounding areas for good observing sites, and we have tracked down quite a few dark places. As well as finding places suitable for an evening session, some members are interested in sites where we could hold our own Starcamp. Stuart has found a local campsite that would offer very dark skies but is quite close and accessible.

That would be for later on in the year. In the meantime, there has been a prediction of a possible meteor shower on 23/24th May 2014, from a new trail of dust, i.e. not one of the regular showers. Since it is new, no-one knows how bright it might be, but we are always hopeful, and a Meteor Watch is planned up on Scout Scar for the night of the 23rd. This will not be a public event, just for EAS members.

Stuart also reminded everyone to look out for noctilucent clouds, as we are approaching the season for them There were some really good ones last year, and several members got good photos.

After the break, we had a presentation from Simon White, who explained the hard work that goes into his amazing photos (and also the occasional glitch!). He had managed to capture comet PANSTARRS c/2012 K1 and M51 in the same frame, but they put up a fight.

Simon was followed by Ian Bradley showing his holiday snaps of the restored 72″ telescope built at Birr in Ireland by the 3rd Earl of Rosse in the mid-19th Century. It was an astonishing technical achievement in its day, but central Ireland was perhaps not the best place to site it. The cloud cover rivals Kendal’s!

Lastly Carol Grayson showed us how she had managed to capture two unusual optical highlights on the Moon, the Lunar X and the Lunar V. In both cases, these are the result of the way the oblique sunlight hits the mountains and crater ridges as the Moon turns, and they can only be seen quite briefly.

Liz Hodgson

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)

1

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

20140502_161941_resized

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…

s m j

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…

cass s

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

earthshine

Moon with Earthshine…

mw2 s

The Milky Way above the lake…

sw1 s

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…

2

…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. 🙂