Stargazing in the Outer Hebrides

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Pre dawn Milky Way on the Isle of Lewis, during the 2020 Hebridean Dark Sky Festival

As a family we’ve visited the Western Isles of Scotland during the warmer summer months, attracted by the wild open spaces, stunning beaches and abundant locations for camping.  Unfortunately the long summer days and short nights are too bright to stargaze, so I’ve never had the opportunity to sample the fantastic dark skies the island has to offer.  I therefore jumped at the opportunity of participating in this year’s Hebridean Dark Sky Festival, organised by An Lanntair and programmed by Andrew Eaton-Lewis.

My outreach involved delivering astronomy talks and stargazing events at community hubs across the island of Lewis.  Over three nights on the island I visited communities at Balallan, Comunn Eachdraidh Nis in North Lewis and the aptly named Edge Cafe over in the west at Aird Uig.

Despite some very wild weather both before and during the festival the three events were a big success, with starry skies materialising in some form at each session.  Skies, when clear, were astonishingly dark, with star clusters and galaxies clearly visible with the naked eye and a glorious sweep of Milky Way evident between the fast moving weather.

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Starry skies from Ness Beach

When presenting my stargazing talks in Scotland I always try to persuade people of the merits of binocular and naked eye observing over telescopes when weather conditions are changeable.  This mantra was well demonstrated during these events, with the agility of binocular observing allowing us to quickly head in and out when breaks in the sky presented themselves.

Travelling to each event in my camper van and sleeping out in the wilds was also a memorable experience.  Wind, sleet, rain and hail all assailed me at various points during my wild camps, but I was always rewarded with frequent starry skies opening above me when I headed out for fresh air.

The people of the island are also some of the friendliest folk you could meet, with Highland hospitality well in evidence wherever I went.  Bounteous servings of tea and cake were never far away!

I very much look forward to participating in the festival again and encourage anyone with an interest in stargazing to consider the Outer Hebrides as a viable winter destination, particularly if you’re seeking some of the very best dark skies available.

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Satellites aplenty

Venus and Mercury

85024035_2842536592490527_233392740522524672_o.jpgThis is how low Mercury grazes the horizon at the moment. A superb shot of Venus and Mercury from Will Cheung this evening.

If you want to sight Mercury for yourself the best chance is right now in the early evenings just after sunset.  Using Venus as a guide, scan the low horizon with binoculars or naked eye.  An unobstructed horizon like the one in the picture above is essential.

Clear skies.

Red Blood Cell Simulations

I’ve recently finished part one of a mini Unity project looking at the stacking behavior of red blood cells in a basic turbulent flow. In this real time simulation you can see how the contact adhesion and stacking rate of red cells increases as plasma Fibrinogen concentrations increase.

Fluid flow was programmed from first principles using some simplified assumptions and custom code generated for red cell attraction and adhesion as a function of plasma content.

This simulation is VR ready so you can don a headset and fly around and study any part of the domain in real time. This simulation can also be ported over to more complex domains.

Stage two of the simulation will include deformation of the red cells during contact with domain walls and other cells.

These stacking effects happen in patients with various blood clotting conditions or super high haematocrits.
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Developed By Mackintosh Modelling and Data Simulations
https://modulouniverse.com/mmds/

Crab Nebula Composite

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This is an amazing composite image of the Crab Nebula supernova remnant. It shows the neutron star at the center, superimposed over the shockwave nebula (whose outline can be observed dimly in a decent telescope).

This is what happens to high mass stars when they run out of fuel. The atmosphere of the star suddenly collapses inward and dramatically rebounds off the compressed neutron core.

Conservation of angular momentum makes the neutron star spin rapidly (a pulsar) and the rest of the star’s atmosphere expands into space releasing huge quantities of energy (a supernova).

This particular supernova was observed and recorded by Chinese astronomers in 1054 AD as a ‘guest star’, in the constellation Taurus.  It remained visible as a naked eye star for over a year before fading.

Dark Sky Burns

“Thou lingering star, with less’ning ray,
That lov’st to greet the early morn…”

After last night I’m convinced Rabbie Burns did all his stargazing with a delicious wrap of haggis in hand.

Haggis hand warmers and Clelland’s address from last night’s sellout Dark Sky Burns event. Big thanks to the Abriachan team for the Burn’s supper fare. 

Due to inclement skies the astronomy moved indoors I got to talk in some detail about the planet Venus and its harsh environment.  A fascinating place that surely deserves more attention in the future, not least for its potential to harbour microbial life in its more clement upper atmosphere.

Why not try looking at Venus through a telescope or a pair of stabalised binoculars? You should be able to make out its phase, just as Galileo did when he first gazed up at it back in 1610.

Betelgeuse visibly dimmer

I can’t get over how much dimmer Betelgeuse in Orion appears at the moment. To my eye Aldebaran (a red giant) in Taurus now appears obviously brighter.

This was an image taken last winter.

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Orion image from winter 2019

Many click bait astronomy articles have surfaced claiming the star might be dimming due to its impending collapse and rebound as a supernova, but Betelgeuse is a known variable star and similar changes in its brightness have been noted in the past, although recent changes appear to deviate from established patterns.

Unusual gravitational waves have also been detected in the vicinity of the red supergiant, adding to the sense of mystery.  It’s important to note that these waves are merely in the vicinity, so could easily be generated by countless other sources behind Betelgeuse.

Still, it’s fun to speculate about the possibility of witnessing a relatively close supernova event in our lifetime.  The last two major naked eye supernovas were recorded in 1572 and and 1054, in Taurus (the Crab nebula) and Cassiopeia (Tycho Brahe supernova).  Both generated enough luminosity to be visible in daylight for several weeks, and shone as new ‘guest stars’ for around a year or so before fading.

Some work published by Dolan in 2016 estimated the impact of a Betelgeuse supernova on Earth and found it to be negligible.  At 500 light years distance the residual energy of the vastly expanded shockwave would be exponentially diminished as it passed Earth.  However the brightness predicted would be magnitude -12.4,  making such an event more luminous than a full Moon!

For the mathematically motivated I enclose an extract from his calculations below.

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Stargazing a Gateway into Nature

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Stargazing can provide mental perspective and wellbeing.  Problems we’ve amplified in our heads can seem much less important under the amazing canopy of the night sky.

Here’s some interesting stats to think about. 

1. The average person in Scotland spends less than 30 minutes a day outdoors.
2. This equates to over 50 years of an average person’s life spent indoors.

This despite growing levels of stress, anxiety and depression.

Yet one of the best, and absolutely free, ways to alleviate stress and anxiety is being in nature, and stargazing gives us that little bit of extra motivation to head outside, especially during the long periods of darkness we experience over winter in Scotland.

Even if you don’t see anything, packing your binoculars and heading out for an evening stroll under open skies is almost never a waste of time. At the very least you get some exercise, and if you’re lucky, a beautiful night sky to gaze up at.

Clear skies.