June Night Sky

The month of June is an extremely exciting month for the astronomical world with many wonders to feast our telescopic eyes upon.  The beautiful June night sky has  some early summer treats accompanied by the warmer nights, maybe not Bahamas’  warm but much more pleasant than the frosty chill of winter evenings.Not only do we have an array of stellar patterns and objects to gaze upon but the 5th and 6th of June 2012 has one of the most rare and marvellous events in the astronomical calendar, the Transit of Venus.


For years Venus slipped between the Earth and Sun unnoticed, but in 1639 Jeremiah Horrocks witnessed the first recorded Transit of Venus with his telescope.This vital astronomical occurrence that allowed accurate discoveries in measurements of the size of our Solar System and more recently the existence of other planets!What is actually happening during the Transit is that Venus is located between the Earth and the Sun so that we can see the dark planetary disc of Venus traveling from one edge of the Sun to the other.The transit of Venus will last over 6 hours long and we are fortunate enough to be able to see the concluding show of the transit’s final hour.Unfortunately for our region it means an early start and you will have to set your alarm clocks for a sinful 04.50 on June 6th! But it will be well worth the effort as this will be the last transit of Venus we will ever see in our lifetime, with the next transit not occurring until 2117! If you plan to take my advice and rise for this early morning sight there are some very important precautions to take other than warning your neighbours you may be outside in your pyjamas!  A very important rule about any observation involving the Sun is … you’ve guessed it, DO NOT stare directly at the Sun with the naked eye! There are many that allow observing of such wonderful solar events, from solar glasses to solar filters. If you want to learn more of the methods advised to watch the transit click the following link that advises you of six great ways to witness this amazing event. The Transit of Venus is a wonderful way to observe our Solar System in motion and enjoy something that has helped answer some of the most prevalent questions in astronomy! For those seeking a more detailed in depth look at the Transit, why not check out the ‘8 Facts You Need To Know About The Transit Of Venus’ on the Armagh Planetarium website.


As well as this celestial wonder early in the month, summer has many goodies on  offer for amateur astronomers.Summer marks the return of the dominant pattern, the Summer Triangle! An unofficial group of stars or asterism found high in the eastern sky around midnight. Made up of 3 bright stars, the famous Vega being the brightest, Altair and then Deneb the dimmest of the 3, this well-known and welcomed asterism links 3 very interesting constellations with some celestial treats to gaze upon. The constellation of Lyra is home to the most famous of the trio, Vega, but it has more to offer than this show stealing star discussed in a previous article, both visually and mythically. Vega is the highest point in the summer triangle but if you can identify the musical constellation you will notice it looks similar to a parallelogram, and if you find the lower ride side of the parallelogram you will find a stellar treat. In the middle of this line you will find the beautiful Ring Nebula M57! To see this beautiful planetary nebula, so called because of its circular rings, you will need binoculars or a telescope.  Lyra also has multiple myths, like other constellations but many believe it be the lyre of Orpheus, the musician of the Argonauts and son of Apollo.He was believed to play so beautifully he could tame wild beasts.

And after losing his love he swore off women forever, making the women of Thrace angry, so angry they stoned him to death, so like many patterns in the night sky, there is much sorrow in the myth behind the constellation of Lyra.

Moving down and to the left of Vega we come to the “tumultuous teen” star Deneb.Deneb is a blue-white super giant with a high mass and a high temperature meaning that it will have a short life span, being relatively young already at only a few million years old, it will culminate in a massive supernovae within the next few million years.This extremely interesting star is actually one of the most luminous stars known with an absolute magnitude of -7.0. Although its distance means it has an apparent magnitude of 1.25 and is only the 15th brightest star in out night sky. It also is one of the largest white stars known measuring 110 times the size of our Sun! This fantastically dramatic star has more to offer than just its wonderful self, but also the constellation in which it is found. Deneb is the brightest star in the constellation of Cygnus the Swan. Cygnus is fairly easy to spot in the summer and autumn sky as it features the prominent asterism within of the Northern Cross, as opposed to the Southern Cross and within Greek mythology it has several stories. One of which is the belief that Orpheus from the myth of Lyra was transformed into a swan after  his death and placed into the sky next to his musical instrument the lyre.

Finally if you look to the lower right of Vega you will come to the blue “Eagle” star Altair, the brightest star in the constellation of Aquila the Eagle.Altair is the 12th brightest star in the sky with an apparent magnitude of 0.77. Located a mere 16.7 light years away it is one of the closest stars visible to the naked eye. In Greek mythology Aquila is identified as the Eagle that carried the thunderbolts of Zeus. It was also believed to be quite a dark figure with the story involving the titan Prometheus who felt sorry for humankind and stole a ray from the sun and gave humans fire. Enraged at Prometheus’s good will but unsanctioned act, Zeus had him chained to a mountain and continuously attacked by Aquila, and because of his Godly existence he would continuously heal, never to die, so quite a dramatic myth behind the beautiful Eagle constellation.  Two major novae were recorded  within the constellation of Aquila the first of which was recorded in 389 BC and was recorded to have been brighter than Venus! The second was much more recent and happened in 1918 which reached a peak magnitude of -1.4 which definitely was the brightest novae in the 20th century but also maybe the brightest novae ever!

When looking up into the Eastern sky at the summer triangle, we can also acknowledge its connection to the Transit of Venus.When the transit occurs we all will be watching eagerly in the direction of the sun in nifty and essential solar glasses, but the hard working Kepler spacecraft will be looking in the direction of Cynus trying to detect new planets orbiting their host stars. This transit method is used to discover new planets and is based on the dimming of stars when a planet moves across the distance of its host star.

Summer sometimes is not much welcomed by astronomers as it reduces the amount of darkness available for peering into the skies.When June 20th arrives some people may hang up their binoculars for the night as this is the date of the summer solstice, when the Earth’s North Pole faces directly towards the Sun and we have the longest period of daylight in the Northern Hemisphere.  Those lucky few who live north of the Arctic Circle will see the elegantly named midnight sun in which the sun is visible throughout the night.South of the Equator we find an opposite occurrence with this date marking the shortest period of daylight and the Sun not rising at all in the Antarctic Circle.

The June solstice officially starts the beginning of the Northern Summer and the Southern Winter so fingers crossed it will be a long day full of sunshine.

For Moon watchers June may be a particular Lunar treat as early in the month, around the 6th onwards for roughly a week, you may see the day time moon! Basically the Sun’s light is reflected off the Moon and we can see it during the day, this is actually true for a lot of the time the Moon is up but is more difficult to spot before a waxing quarter Moon and after a waning quarter Moon, but never during a New Moon.

Although the summer night skies are much shorter than other seasons, it still has many treats to offer us, but June seems to offer more daytime wonders this month as opposed to the night time delights, especially with the rare transit of Venus, so please do not forget to set those alarm clocks and enjoy June’s short night skies.