EYES ON THE NIGHT SKY: APRIL 2018
Welcome to the April edition of Eyes on the Night Sky. Springtime nights can provide a rich banquet of celestial delights before the nights get too light to enjoy the dark skies of the Elan Valley. Typically, April nights can be wonderfully clear and not too cold!
For planet lovers, a conjunction of Mars and Saturn occurs on 2nd April at around 4am BST. Saturn is favourably placed with its rings wide open and makes a wonderful telescope target. Low on the south eastern horizon, Mars will only be 1.16 degrees distant from Saturn – which is the thickness of your little finger held out at arm’s length. Both planets fit into a binocular’s field of view. Another treat to watch out for is M22, a globular cluster in Sagittarius – only 0.4 degrees from Mars! You might be able to see it with the 8” telescope but the Moon might make the skies too bright to see it.
Jupiter rises around midnight BST and is visible all night.
The New Moon falls on 16th April and the Full Moon on 30th April.
For owners of binoculars, small telescopes and eyes, try and find one of the most well-known double stars in the sky: Mizar and Alchor. This target was the first bright double star to be discovered as far back as 1617. Situated around 80 light years from earth and around 1.5 light years apart, the two stars can be seen with the naked eyes. The pair can be clearly seen through binoculars and provides a pleasant view through small telescopes. Take another look at Mizar with your small telescope – you will see that it’s also a double, consisting of Mizar A and Mizar B!
The Lyrid meteor shower occurs between 16th and 25th April, peaking on 22nd April. They are created from the debris of comet Thatcher and will peak around 20 meteors per hour. The Lyrids radiate from the constellation of Lyra which represents a Lyre, an ancient musical stringed instrument and is associated with the mythology surrounding a Greek poet/musician named Orpheus.
M96 and M95 are two galaxies in Leo that were discovered by French Astronomer Pierre Méchain in 1781. He reported the discovery of the two galaxies to Charles Messier, who added them to his catalogue. M95 and M96 belong to the Leo I group within the Virgo Supercluster and are gravitationally bound. M96 is among the brightest, being some 80,000 light years long. Its neighbour, M105, was added to the Messier Catalogue in 1947. M95 is barred spiral galaxy and contains a jaw dropping 40 billion stars. Through eight or ten inch telescopes, its spiral structure can be discerned under dark, exceptionally clear skies but normally appears as a diffuse ball of light. M95 was also a show-stopper on March 19, 2012, when a supernova was observed 115 arc seconds south of its centre and shone with the brightness of 500 million suns. To observers, it appeared like a bright star within the diffuse glow of the galaxy. Once you get to observe galaxies on a regular basis, it is very exciting to observe a supernova; seeing a “bright star” appear and fade over time.
Finally, you will have come across the term 'light years' as a unit of measurement, expressing astronomical distances. To help you understand the concept of this unit of measurement, take a look at this interactive animation: http://stars.chromeexperiments.com
See you next month!