Coventry and Warwicks Astronomical Society

On Friday the 14th of September I will be once again re-visiting Coventry and Warwicks Astronomical Society.

This time I will be presenting The History of Manned Space Flight, The Space Race, between The USA and Russia, which resulted in the magnificent Apollo lunar landings between 1969 and 1972.

I am really looking forward to seeing them all again.

Their meetings start at 7:15pm.

Venue:
Earlsdon Methodist Church Hall,
Earlsdon Road South,
Earlsdon,
Coventry,
CV5 6NF

Kelling Skycamp Beckons

The darker skies of Kelling Heath and Loughton Astronomical Society’s annual Autumn Kelling Skycamp are calling.

Well, it is that time of year once again.

Towards the end of this week, and over this weekend, for the main event, hundreds of astronomical-minded folks will be gathering in North Norfolk at this much anticipated annual event. I feel that Kelling starts the years observing season off with a real bang.

It’s a great sociable event, so don’t let the current weather cloud forecast put you from coming along. If it does clear, there’s the chance to see some really dark skies, and look through some huge telescopes people bring along. Or just sit outside the tent with a glass (or a hot cuppa) in your hand and sit underneath the stars and take it all in.

I’ll look forward once again catching up with some of my very good friends and if you’re coming along, come and find me to say “Hello”.

I might even have some of my books with me to sell too. 😉

So, here’s to another great weekend of astronomy (With a fair bit of socialising added in).

Dave

Sky Diary for September 2018

My free monthly sky diary for September 2018 showing the events of the night sky visible from the UK is now available in pdf form to download and print.
Click here, or on the image below to download the pdf.

I also have a sky diary to share on Google calendars.
Click here to go to my Google calendar.

More sky events will be added to the live Google calendar as more information becomes available.

FAS Convention – 22nd September 2018

The Federation of Astronomical Societies is holding it’s annual AGM and convention.
Click on the white text above for more details.

This year it is being held at The University of York on the 22nd of September.

Starting at 9:00am after a short AGM, a whole day of astronomy goodness awaits.

There’s a great line up of speakers for the day:

  • Prof. Mike Cruise – The Gravitational Sky.
  • Prof. Katherine Blundell OBE – Black holes and spin-offs.
  • Prof. Brad Gibson – How the Universe will end…
  • Charles Barclay – Reaching for the Stars – Developing the British entry for the Astronomy and Astrophysics Olympiad.
  • Prof. Ian Robson – The Changing Scene in Astronomy.
  • Prof. John C. Brown OBE – Sun Plunging Comets (Hypersonic Snowballs in Hell).

There will also be a number of trade stands, including yours truly.
So come along, say “Hi” and feel and sniff comet 67P.

Tickets are £6 for members of Affiliated Astronomical Societies, or £8 if not.

Book your tickets for the FAS Convention by Clicking Here.

 

Imaging Moving Comets – Shorter Exposures Rule.

Imaging comets offers many challenges over deep sky objects.
Deep sky objects stay still relative to the stars, so as long as you are tracking the sky OK, they will show lots of details on long exposures. Comets are notoriously difficult, especially when they are approaching perihelion (the closest point to the Sun), when they are moving at their quickest in their orbit, or relatively close to Earth, when their perceived motion is at its greatest.

When these two circumstances coincide, the comet appears to be really shifting against the background stars from Earth. So unless the imagers telescope can be tracked on the comets motion, details in the comets tails or coma will quickly blur as the motion of the comet smears it across the image.

The animation below shows the motion of Comet 21P / Giacobini-Zinner on the 16th of August. Click here for my guide to viewing Comet 21P.
This was produced using 40 second subs, taken immediately after one another. You can quite clearly see how quickly this comet is shifting between each exposure.

There are ways and means around this to make sure that the image shows maximum detail. The computer can be set to follow a set track in the sky, or, if the comets pseudo-nucleus is bright enough, auto-guide on the comet itself.

When these techniques are used, images of the comet are superb.

Below are two images of Comet C/2013 US10 / Catalina I took on the morning of the 21st of December 2015. This was a very fast moving comet.

But not all imagers are as well advanced as this, or the comet isn’t bright enough to guide on. So how can they cope with this movement?

The answer lies in reducing the exposure of individual subs taken of the comet.

In really fast moving comets, like Comet Catalina above, despite the pseudo-nucleus in this case being bright enough to auto-guide on, the comets movement was so quick, that I had to keep each exposures below 15 seconds each, to prevent the comet blurring. Each sub-image was taken one after the other. I kept imaging the the comet for over two hours before the sky started to brighten as dawn approached.

You would have thought that catching over two hours of data would have given me a superb image when all these subs were stacked together. Not So!

Have a look at the two Catalina Images shown above again. These are stacks of images taken about an hour apart. Look at the detail in the straight ion tail, pointing towards the right hand side of the image. There is a disconnection event visible in the first image, and this “ripple” was seen to move down the ion tail over the two hours as shown in my animation below.


Had I stacked all the images over the two hours, any detail in the ion tail would have smudged itself out of existence and been completely lost, due to its movement. So to produce the individual images in this animation, I had to effectively stack a small selection of subs from different time frames throughout the imaging period to produce my final series of images.

So, the two key points to take away from this is:
If the comet is moving fast, and the comet is too faint to guide on, use short exposures to reduce the movement of the comet during each exposure.

If imaging the comet for an extended period, do not be tempted to stack all the images over that time as any detail will blur itself out.

You should then end up with something that starts looking something like this.
Comet C2014 Q2 / Lovejoy – 6th February 2015.

 

Trying something new…

So, we moved home on the 4th of July.
Much as I hate the way US traditions are infiltrating British culture, this date meant that due to us downsizing the house, we were no longer bounded by me having to go to work.
That day really was Independence Day for the Eagle household.

So after a frantic 6 and a bit weeks of having trades in the house, I have finally been able to get the “observatory” up and running.

After selling the dome, I had a set budget for my new setup. I would invest this money wisely, to try and upgrade some instrumentation, if possible.

So instead of a dome or roll-off roof, I opted to cement my pier in the chosen location in the garden and erect an off-the-shelf shed nearby, which would eventually have power connected to it. This reduced the costs of my new observing facilities significantly.

So, by making this change, as part of my upgrade, I managed to get a Celestron C11 at a very good cost, and still had enough left in the budget to purchase an Altair Astro 183C Hypercam.

So I’ve got a new camera. Not for the first time, I find myself once again on that very steep learning curve.
How does the camera work? What are the best settings to use?

On the evening of the 16th of August, the skies looked like they were going to be clear after a cold front went across bringing rain that morning. The pier was set up, so I ran an extension lead out for power and connected the computer to the mount. A quick port change and everything talked perfectly as if it had never moved from the observatory. As the sky started darkening, I took a quick look at the Moon, capturing a quick series of images using the Hypercam before it slipped behind the neighbours house.

Not bad considering the sky wasn’t even dark at this time and shows the field of view obtained with this camera when used with my 190 Mak-Newt.

As the sky darkened further I focussed on a bright star using the Bahtinov Mask. If you haven’t got one of these brilliant devices, how long does it take you to focus the camera properly? So first plan was to go capture a comet.

So, I slew the scope over to Comet 21P /Giacobini-Zinner, visible in the north eastern sky. This comet has been very bright lately, as it approaches perihelion.
Click here to read my guide to this apparition of Comet 21P.

I took quite a number of images saving as all different formats to see if I can tweak an image out. It was a real challenge. Initial images looked fine on the screen, but when I came to stack the images using my trusty software Deep Sky Stacker the images were blurred. The stars, despite many being detected, the images just would not stack.

I even went over to M13, a big bright object, to see if this would help.
The same thing happened.

I finally got tired and packed up at 1am.

So the next day, a few lengthy manual image processing sessions started to try and retrieve some images from all the data I had collected. The results are still monochrome, so there’s something I’m still not doing right.

Comet 21P – Subs manually stacked and processed in Photoshop.

M13 – Subs manually stacked and processed in Photoshop. (The Propeller is nicely visible).

I finally found 5x 40 second subs saved in FITS format that would stack correctly. Still no colour to speak of, but hey, it’s a start. Despite being only a total of just over 3 minutes integration time, there are some faint stars showing up there and some nice structure in the head of the comet. So the initial results are starting to show the potential of this camera.

Onwards and upward… Here’s to next time.

South West Astronomy Fair – 11th August 2018

I have the privilege of speaking at The South West Astronomy Fair this Saturday (11th August).
@Flat_Tim, Buzz and I will once again “Celebrate Tim Peake’s Principia Mission”, so there will be more fun and games for all ages.

CelebrateTim

I am really looking forward to the day and being able to visit the historic Norman Lockyer Observatory.

It should be a great day.

Venue:
Norman Lockyer Observatory,
Salcombe Hill Road,
Sidmouth,
Devon,
EX10 0NY

Directions:
The Observatory is about 2 km east of Sidmouth and 0.5 km from the coast. It is on the north side of Salcombe Hill Road which runs between the town and Trow Farm, where it joins the east-west A3052.

If you are travelling via the M5 leave at Junction 30 and head towards Sidmouth on the A3052. Continue on this road through Newton Poppleford and past the Sidmouth turnings and through Sidford.  At the far end of Sidford take a right turn on to Fortescue Road just after the Blue Ball pub. After 2 km turn left up Salcombe Hill towards the Observatory.

Sat-Nav

Enter the postcode EX10 0NY,

use the coordinates:
Latitude 50° 41′ 16″ N
Longitude 3° 13′ 07″ W

or National Grid Reference SY 139 883.

or by Bus or train:

There are rail stations at Exeter and Honiton.
Local buses to Sidmouth run from Exmouth (157), Exeter (52A and 52B), Honiton (52B and 379) and Seaton (52A).
These have a frequency of hourly or better.
A longer-distance service X53 runs between Exeter and Poole, but passes through Sidford rather than Sidmouth.
From June to September a shuttle bus service, the Sidmouth Hopper, runs half-hourly between the town and the Observatory.

 

Peterborough Astronomical Society – 2nd August 2018

Here we go again. 🙂 More Tim Peake fun and games for all ages.

@Flat_Tim, Buzz and I will be out once again on Thursday the 2nd of August.

This time it’s a visit to my old friends at Peterborough Astronomical Society.

The title of the audience-participation presentation evening is my ever popular:
“Celebrate Tim Peake’s Principia Mission”.

CelebrateTim

I am looking forward to meeting up with this group again at Sacrewell Farm.

Like all my other visits out with this presentation, I’m really looking forward to having a lot of fun with them all during the audience participation bits. As I know them well, I have a few “victims” I can call on if no willing volunteers come forward.
I’m sure that, like the other groups I have taken this presentation to, that they will really enjoy the fun evening planned for them. That’s if they’re not bored with me yet, as it was only a couple of months ago that I stood in for another speaker for them.

I wonder how keen they will be compared to some of the other groups about having their selfies taken with @Flat_Tim at the end of the evening.

All are very welcome, especially kids, as this presentation is aimed at any age group, from 10 – 110. So bring along your children, grandchildren and grandparents along.

So if you are in the area, come along and say “Hello”.

This is very timely as Tim’s Soyuz Capsule goes on display at Peterborough Cathedral on the 11th of August, until the 5th of November. Click this link for more details.
So if you can’t make my talk, make sure that you visit the Cathedral to see the Soyuz capsule (TMA-19M) and Sokol KV-2 space suit. There is also a virtual reality space descent simulator to enjoy.

Meeting starts at 7:30pm.

Venue: Sacrewell Farm
Thornhaugh,
Peterborough
PE8 6HJ
(Just off the A1).

For more details about Peterborough Astronomical Society, click this link:
Peterborough Astronomical Society.

 

Mars Opposition and Lunar Eclipse – 27th July.

Mars comes to opposition and is at its biggest and brightest on the 27th of July.

But that’s not going to be the only bright red object visible in the sky that evening.

That same evening, the Moon will rise when it is deep in the Earth’s shadow, a full lunar eclipse. Rising a red colour it will make a fantastic sight, rising in the south-eastern sky a little while after Sunset. Try and get a feature in the foreground to get a stunning photograph of the ruddy moon-rise. The event will be visible to the naked eye and should look even better in binoculars or a wide-field telescope. Once the eclipse has finished, turn your telescope towards Mars.

Progression of the Earth’s shadow timings are as follows:

Moon Rise: ~19:50 UT (~20:50 BST). (Will vary depending on your location in the UK).
Greatest eclipse: 20:22 UT (21:22 BST).
Total eclipse ends: 21:13 UT (22:13 BST).
The Moon will still be only about 19 degrees above the horizon as totality ends.
Partial eclipse ends: 22:19 UT (23:19 BST).
Penumbral eclipse ends: 23:28 UT (00:28 28th July. BST).
By the end of totality Mars will be more than 10 degrees above the horizon, so should be a little bit more observable, but will still be challenging so low down below the Moon.

Image of eclipse circumstances below taken from Fred Espenak’s excellent Eclipsewise Web site:
http://www.eclipsewise.com/lunar/LEprime/2001-2100/LE2018Jul27Tprime.html

The map below shows the visibility of the eclipse from Earth in a bit more detail.
(Taken from http://earthsky.org).

So get out that evening, (cloud permitting) and enjoy both the spectacular lunar eclipse, and then Mars in all it’s glory (global dust storm permitting).

The simulated images below show how the apparent disk size of Mars changes over the months either side of this opposition.

Dave

Moving. One of the most stressful times?

We often hear that moving home, alongside getting married, having kids or somebody close to you dying, is a very stressful time.

Well, we’ve just moved and downsized the house. Added to this, I have also sold my observatory. This should have added to my stress, but so far, our decision has already completely changed our lives. The funds this has released has enabled me to leave work early, (“retire”) and, once the work has been done to get the house up to scratch, we should just about have enough left (time will tell! Ulp!) to pay the bills for the next few years until I can start to claim my pension. I don’t earn much from selling my books, but when the colder days set in, and most of the house jobs are done, I will be sitting down and writing more astronomy books, as my previous editions have gone down so well.

We thought it was peaceful in our old garden until we moved here to Raunds. It’s amazing just sitting in our new garden hearing very little traffic, plus surrounded by bird noise, especially the multitude of swifts at this time of year, squealing and chasing one another and the red kites calling regularly as they patrol the area.

Of course being free from the commitments of work, leaves us in a fantastic position to take up lots of opportunities that we couldn’t before. A quick impromptu trip down the The Mall in London to view the RAF100 Flypast, or helping out my mate Andy Green with his Stardome Planetarium, when he needs me.

All sorts of other new and exciting opportunities seem to be coming at me from all sides at the moment. So our decision so far seems to have been proven to be the right one. I may regret saying that at some point, but we’ll ride with that one for now.

Yes, it’s been hard work preparing to move and living in the current mess, while the house gets sorted out, is also a bit of a challenge.

This week the kitchen gets ripped out, two stud walls are coming out and the new kitchen being fitted the week after, before the decorator comes in to make good.

This weekend I grappled with an enormous ivy which was covering the bottom edge of the garden. Yesterday I won the first battle. This morning I won the war, taking out the thick root and reclaiming another 5 feet of garden. I have the sore hands, muscles, cuts and bruises to prove it, let’s call them my battle scars, shall we? But its a bit of ground definitely worth fighting for. This will be used for the site of my new observatory (a shed this time). This is planned to be installed at the beginning of August, the base for it is being laid late next week.

So it’s all go. So has it all been very stressful?
More like exciting and so very rewarding as we can see the rapid progress that is being made to make the house ours.
And to think, we only moved into the house 10 days ago and have made so much progress, both inside and out.

The pictures below show the before and after views of the vine.
Now where the heck are we going to get rid of all those cuttings?