The Courier & Advertiser (Perth and Perthshire Edition)
Binoculars make stars bright
We are nearing the conclusion to a difficult year so far for stargazers, according to Craigie’s expert contributor Ken Kennedy.
The Dundee Astronomical Society stalwart is now hoping readers will have a few clear nights during December in order to enjoy the winter sky and its many wellknown constellations at their glorious best.
Ken says the simple act of using a pair of binoculars can help reveal many celestial objects that are otherwise difficult to see – and made all the more obscured by often blinding modern street lights.
As an example, he picks out the striking Double Cluster of Perseus, which has been intermittently visible above Courier Country skies on recent nights in between the clouds.
Ken points out that the Perseus star pair are considered as “young” at an estimated age of 12.8 million years, in comparison to the sun at 4.6 thousand million years – so definitely some hope there for any readers feeling a tad over-the-hill!
He adds that the famed aurora has been seen both locally and throughout the UK several times in recent weeks, and encouragingly he expects the frequency of such spectacular displays to increase over the course of the next 12 months.
Looking ahead to the prospects for astronomy buffs in the shorter term, during December, Ken tells Craigie that Perseus rises to its highest point – almost overhead – at 10pm GMT during the month.
He says: “I often recommend using binoculars to scan the sky and this is no exception during December. If you find the brightest star of Perseus, Mirfak, then the W of Cassiopeia, scan from Mirfak to the
left – or eastern – two stars of Cassiopeia. You are bound to come across a striking pair of young star clusters popularly known as the Double Cluster of Perseus. These have an estimated age of around 12.8 million years and contain several thousand stars. They are 7,500 light years distant but are approaching at a speed of 38km per second.
“The December sky has a scattering of star clusters and there is nowhere better to look for them than in the constellation of Auriga,
just east of Perseus. Auriga was widely interpreted by ancient astronomers, but most popularly as Myrtilus, the charioteer.
“The brighter stars form a hexagon, sometimes described as looking like a kite. The brightest and highest star is Capella, so – binoculars out again – scan down from Capella to the lower left of the main stars.
“On your way you will come across three distinct star clusters given the designation Messier 36, 37 and 38 by the comet hunter Charles Messier in 1764. These clusters range in age from M36 at 26 million years to M37 at 400 million years and in distance between 3,500 and 4,500 light years.
“The winter sky is now unfolding and below Auriga is the V-shaped star cluster, the Hyades, which forms the head of Taurus the bull. Taurus is a very interesting constellation which we will have a look at in more detail next month together with the jewel of the winter sky, Orion.”
Ken adds: “The final major meteor shower of the year, the geminids, has its maximum at 2am on December 14. The particles which cause meteors as they enter Earth’s upper atmosphere appear to originate from the object 3200 Phaethon.
“Meteoric particles are usually associated with comets, but Phaethon is classified as an asteroid and the geminid meteor shower was first observed only as recently as 1862.
“Meteor numbers have been increasing gradually over recent years, and on dark nights more than 100 per hour may be seen.
They are quite slow and often bright, but we will struggle to see anything like that number this year as the moon is 10 days old and will be high for much of the night.”
Ken concludes: “Mercury sets one hour after the sun at the end of December and will not be visible throughout the month. Venus will be bright but low towards the south west, setting about two hours after but will generally be in quite bright twilight until shortly before it sets.
“Mars is placed very low in the south east, rising about an hour and a half before the sun – not well placed during December for observation. Jupiter remains bright but low in the southern sky and will be due south at around 4.30pm, and sets at 9pm so in a good position for observation.
“Saturn, less bright, remains about 15° west of Jupiter. By mid-december Jupiter, Saturn and Venus will be in line from south to south west at around 5pm. The moon is new on the 4th and full on the 19th.”