Summer Solstice at the Shielings

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Come and join us for an outdoor walk and talk to the Sheilings above Loch Ness. Learn about summer plant lore and old dairying activities from Abriachan’s Suzann and Christine as we walk up the hill.

Once we reach the Shieling local astronomer Stephen Mackintosh will give a talk on ancient astronomy and how many cultures would mark the solstices in days gone by.

Some traditional refreshments will be available at the top after the walk (30 mins uphill).

Meet: Friday 21st June after the Abriachan Highland Games at 8.30pm.

Park at the fank carpark NH559348. For detailed directions please advance email abriachanforest@gmail.com or call 01463 861236. All ages welcome.

Tickets available via Eventbrite.

Due to the outdoor nature of this event it may be cancelled due to very poor weather. Please check the ‘Abriachan Community ‘or ‘Highland Astronomy’ Facebook pages for details on the day. This event is part of the Star Stories Astronomy and Storytelling programme, part funded by the STFC (Science and Technology Facilities Council).

Event image rights: Karl Normington.

https://www.flickr.com/photos/36266724@N06/

Night Shining Clouds

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A few weeks either side of the summer solstice is the best time to observe ‘noctilucent’ or ‘night shining’ clouds.

These wispy collections of ice crystals are the highest clouds on Earth, located in the mesosphere up to 50 miles overhead. They’re too faint to be seen in daylight and best observed when the Sun is between -6 and -12 degrees below the horizon.

At the moment at Highland latitudes this gives you an approximate window between 11.30pm and 3am in the morning.

Clear skies.

Scotland – Land of the ‘almost’ Midnight Sun

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A stunning sunset captured over the Isle of Rum

In the north of Scotland we’re about four days away from losing all astronomical twilight and entering a period of sustained ‘nautical twilight’.

During this time the centre of the Sun’s disk never dips more than 12 degrees below the horizon, rendering our clear night skies a dark azure blue, with only the Moon, planets and brightest stars visible after midnight.

This will continue until mid July when astronomical twilight finally reappears.

Contrast this with London, where astronomical twilight continues right through mid summer, producing much darker night skies, but arguably less beautiful and prolonged sunsets.

Clear skies.

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We’re leaving astronomical twilight behind for several months here in the north of Scotland

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Significantly darker night skies persist through mid summer in southern England.  Here’s the contrasting data for London.

ISF Talks – Island Universes

I’ve recently finished delivering two public lectures on Galaxies at this year’s Inverness Science Festival.

The theme of my talks was ‘Island Universes’, telling the tale of when and how we discovered our Milky Way isn’t the only galaxy, and how the teeming multitudes of spiral nebulae, hitherto believed to be collapsing dust clouds, were in fact individual galaxies.

The talk started with some observational astronomy, before discussing the great debate of 1920 between Harlow Shapley and Heber Curtis.  The main unresolved issue here was the distance to the spiral nebulae, particularly Andromeda, which was unknown.  This lead us into pulsating stars and the work of Henrietta Swan Leavitt, who systematically analysed and determined the period luminosity law for cepheid variable stars.

Finally we discussed Edwin Hubble and the ramifications of his observations on the red shift of distance galaxies, and how this has informed our current understanding of the history and future dynamics of the universe.

I’ll let some choice slides do the talking from here on.

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Our own galaxy ‘The Milky Way’ is big.  If you tried to travel from our position to the galactic nucleus at the speed of the Voyager spacecraft it would take you over 400 million years.

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A 1900s image of the Andromeda nebula.  Back then the consensus was these spirals were large collapsing dust clouds, a bit like the star forming Orion nebula.  The idea that they could be separate galaxies like our Milky Way seemed inconceivable, yet that’s where the evidence eventually lead in the 1920s.

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Determining the distance to spiral nebulae (as they were known pre 1900) required a new way of determining distance from so-called ‘standard candles’.  Leavitt’s law was invaluable when Hubble turned his attention to Andromeda in 1922.

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Hubble discovered the galaxies were all rushing away from us.  However this phenomena is actually a metric expansion of space itself, and therefore has no intrinsic centre.  Some of the most distant galaxies are receding away at faster than the speed of light – again due to the expansion of space itself, which has no speed limit imposed.

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There were lots of questions on M87, the giant elliptical galaxy whose black hole was recently imaged by the Event Horizon telescope.

Q&As are always lively after astronomy and space talks, and the younger audience members always surprise me with their amazing knowledge and frank curiosity.  Some choice sample from the two evenings below.  Answers on a postcard please .

1. Is the singularity at the end of a black hole the size of the Planck length?

2. If a giant hole suddenly appeared in the Earth how many Pluto’s could you fit inside it?

3. Do supermassive black holes continue to grow until they devour the host galaxy?

GSC On Tour

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Ross teaching us how to make a comet in a bin bag!

We had a great day of outdoor and indoor astronomy learning with our guests from Glasgow Science Centre on Saturday.

Ross and Andrew travelled all the way up to the A9 loaded with space and science kit to kick off this year’s first daytime event for the Star Stories programme.

Ross ran a fascinating hands-on Comet making workshop in one of the outdoor woodcraft sheds, demonstrating how Comets form and disintegrate as they travel round the Sun.

Meanwhile Andrew presented an indoor planetarium show using a projector and Stellarium software, taking audiences across the night sky and explaining some of the science and mythology surrounding the constellations.

Everyone seemed to have a great time and we’re looking forward to continuing the summer programme with our Summer Solstice event on the 21st June.  Please check my facebook page for booking details in the weeks ahead.

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Interactive exhibits kept the youngsters entertained between learning streams

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Outdoor astronomy learning

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Andrew’s star hopping presentation

 

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Galaxy Photobomb

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When an entire galaxy (faintly) photobombs your night sky picture!

I was sorting out some of my recent images from the west coast and spotted the Andromeda galaxy. That’s my camper van at the bottom looking west over the sea near Arasaig. Sky glow is from the recently set Sun.

That fuzzy elongated smudge I’ve highlighted is the combined light from over 400 billion stars. A completely separate island universe over 2.5 million light years away.

Here’s a few other pictures from this excursion posted below.

 

Stargazing at Roseisle

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Starry skies over the Moray coast

Amidst a very busy schedule last month I managed to head out to Roseisle (along the Moray coast) for some observing and a wild camp.  My original mission was to try and catch a geomagnetic storm predicted by the MET office space weather forecasts.  As it happened the promised aurora didn’t arrive but I did manage to get some photos of the starry skies that opened up on Saturday night, starting with the International Space Station.

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Not the most fantastic ISS shot but I only had about 20 seconds to set up after running down the dunes to capture the pass!.  The station is actually travelling from west to east here, towards Sirius (bright star on left)

From there I took a number of pictures hoping to capture some aurora, but instead imaging the crisp starry skies.  I’ll let the photos do the talking from here – please read the caption notes.

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This image of the Plough (minus Alkaid) was snapped while I was still under the trees, on my approach to the beach.  You can clearly see the naked eye double star Mizar-Alcor at the bottom of the image.  The main stars in the Plough are roughly 100 lights years away.  Our Sun would not be visible naked eye if placed this far away which tells us something about the scale and luminosity of these titan stars.

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Looking north towards Burghead where I hoped to capture some aurora.  Instead I picked up the rich star fields within the Milky Way near Cassiopeia.

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One of many passing satellites.

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An interesting shot looking north west.  The bright white light is the Portmahomack lighthouse and the orange light pollution on the right is likely from Helmsdale.  Perhaps the most interesting feature in this photo is the faint smudge of light in the top left.  That’s the Andromeda galaxy – a separate spiral galaxy (larger than our Milky Way) over 2.5 million light years away.