I’m currently working with the Strathnairn community to locate and certify a public observing area.  There’s a few potential sites under review and Caroline Tucker who runs the community magazine invited me to submit an article on stargazing and dark skies.  It’s reproduced below:

Epsilon Lyrae is a nice easy double star you can view in binoculars all year round in northern latitudes. It sits high in the southern sky very close to the bright star Vega, so is relatively easy to find.

Viewed with the naked eye, it’s just a normal looking 5th magnitude star, but point some binoculars at it and it splits into two clearly separated stars. Things get even more interesting if you train a telescope on the pair, as they’ll split again, revealing a pair of double stars!

The main pair are gravitationally bound and orbit each other every 1200 years with a separation of 160AU (or 160 times the distance from Earth to our Sun). The system is approximately 170 light years away.

Double star systems are the norm in our galaxy with over 60% of star systems containing double or multiple stars orbiting each other at various distances. Our Sun, so far as we know, is a lone wanderer.

Simulations of quadruple star systems suggest they’re relatively unstable, and easily disturbed from their rotating reels by the passing tug of galactic neighbours.

Neptune reaches opposition on September 2nd meaning it’s at its closest approach to Earth over the next while. It’s up almost all night in the southern sky within the constellation Aquarius, below and right of Pegasus.

You’ll need a good horizon to see it however as it’s very low on the horizon this far north, never getting higher than 27 degrees.

During opposition Neptune will be at a distance of 28.94 AU with a disk size of 2.4 arcsec. In a good telescope of 6 inches or more you should be able to see a tiny blue disk and perhaps its companion Triton.

Neptune was first observed in a telescope in 1846.  It’s existence was implied from solar system models rather than from direct observation.  Like Saturn and Jupiter, it’s a gas giant with an atmosphere largely composed of hydrogen and helium, but this far out it also contains some “ices” such as water, ammonia, and methane.  

Neptune also has some of the weirdest and wildest weather in the solar system, with recorded wind speeds as high as 2,100 kilometres per hour!  This is what drives some of the mesmerising cloud streaking witnessed during Voyager 2’s flyby.  It’s also an extremely cold place – its cloud tops have recorded temperatures as low as -220 C.  Not surprising given how far it is from the sun.

We’re finally emerging into some periods of significant darkness in the north of Scotland. Tonight marks approximately 1.5 hours of true astronomical darkness at latitudes 57 degrees north.

Astronomical darkness is defined as the sun being more than 18 degrees below the horizon, which it will tonight between 12.30am and 2.13am. Notwithstanding the waning crescent moon rising after midnight, conditions should be pretty good for general observing. Local weather reports indicate clear skies from about 7pm too.

Star profile: Vega (Arabic for “the swooping Eagle”)

Vega sits above the little diamond of starts in Lyra

After midnight look south west and directly up, almost towards the zenith. The bright blue-white gem you might see shining above will be Vega – the 5th brightest star in northern skies. Vega sits above a lovely little diamond shaped constellation comprised of four moderately bright stars (within the constellation Lyra).

Vega has been studied comprehensively by astronomers and has some unusual properties. One is its incredibly rapid rotation which causes its mid drifts to bulge out fantastically, yielding very large equitorial radius measurements. If Vega rotated only another 7% faster its would rip itself apart due to incredible centrifugal forces.

Vega is also big and young as far as stars go – with a mass of 2.3 Suns and 37 times more bright. Because of its size and energy Vega won’t survive as long as our Sun and will remain in a stable state for only a fraction as long as our home star (perhaps 500 million years).

The rule of the Cosmos as far as stars are concerned appears to be “burn bright and die young…”

This weekend is peak activity for the annual Perseid Meteor Shower.  Below is a quick guide for successful viewing under northern skies.

Guidelines for Viewing

You don’t need any special observing equipment, just your eyes and a good clear horizon away from as much street lighting as possible.

It’s much more enjoyable viewing meteor showers in a relaxed state, so why not get an old deck chair or picnic rug to lie down on? Meanwhile avoid any hand torches or mobile phone use as it’ll destroy your dark adaption.

After 11.30pm on Friday, Saturday or Sunday, look North East. The constellation Perseus will be about 30 degrees above the horizon, below the distinctive W shape of Cassiopeia.

This is the area of sky from which the meteor activity will originate. At peak (probably after midnight) up to 100 shooting stars per hour could be seen, although its worth pointing out that a waning gibbous moon will begin rising in the east around the same time, which could blot out some activity.

These shooting stars are remnants from the comet Swift-Turtle which last hurtled around our sun back in 1992, but left a trail dust and ice particles which impact our atmosphere at a whopping speed of 135,000 mph.

Capella

While you wait for meteors why not contemplate the very bright star ‘Capella’, sitting just left and below Perseus. Capella appears to be one star but is actually a binary system – composed of two giant stars orbiting each other at about 70% the distance of our Earth from the Sun (you’d need a very powerful telescope to see both). These giant stars have exhausted their hydrogen stores, and cooled and swollen, moving off the main sequence towards red giant oblivion.

Capella – The 6th brightest star in the sky