Star Gazing for Beginners

Looking up into the night sky can be quite baffling – so many pin pricks of light and no way of knowing what we’ve called them and how far away they are from earth. The Isle of Wight has a very good dark sky, especially along the west coast (avoiding the bright lights of Brighstone) and somewhat ironically down near the lighthouse at St Catherine’s Point, but as long as you aren't in the middle of a town you will get a good view on a clear night.

With the unaided eye you can see the constellations; shooting stars or meteors, several of the planets (Mercury, Venus, Mars, Jupiter and Saturn) and of course our moon. Also visible (especially in the summer) are some of the man-made intruders that are rarely visible by day, such as communication and weather satellites, and you might see the International Space Station.

A decent pair of binoculars is a great way of getting in to astronomy as they gather in more light than the human eye, so not only do they bring things closer but you can actually see a lot of stars that are invisible to the unaided eye. The milky way is the large cluster of stars that flows across the sky and looks like a cloud.  You can follow this with binoculars and see just how many stars surround us, although it is better seen in the summer and in areas without any light pollution. If you then turn your binoculars on the moon you can see her many craters jump into focus.

Orions Belt

Without binoculars you can easily identify a few constellations in the night sky. Orion’s Belt is perhaps the most readily identifiable feature with its line of three bright stars: Alnitak, Alnilam, and Mintaka.  In the Northern hemisphere, Orion's Belt is best visible in the night sky during the month of January at around 9.00 pm and finding it is the easiest way to locate the constellation Orion in the sky. But don’t make the mistake of thinking that these three stars are actually near each other – they just appear that way.

Alnitak is approximately 800 light years away from Earth and, taking into consideration ultraviolet radiation, which the human eye cannot see; Alnitak is 100,000 times more luminous than the Sun. Alnilam is approximately 1340 light years away from earth and shines with magnitude 1.70. Considering ultraviolet light Alnilam is 375,000 times more luminous than the Sun. Mintaka is 915 light years away and shines with magnitude 2.21 and is 90,000 times more luminous than the Sun. Mintaka is a double star and both of its stars orbit around each other every 5.73 days.

Close to Alnitak, just to the south, is the renowned Horsehead Nebula, a so-called dark nebula that is not visible in telescopes but quite spectacular in long-exposure photographs. You can also see the Orion Nebula, a star (or stellar) nursery, which is the middle ‘star’ in the sword of Orion: the three stars located south of Orion's Belt. The star appears fuzzy to sharp-eyed observers, and the nebulosity is obvious through binoculars or a small telescope.

The Great Bear

Once you’ve memorised all of that you’ll be well on the way to impressing your friends and family but you do really need to learn about Ursa Major, 'The Great Bear' or 'Plough' constellation (also known as ‘The Big Dipper’ in the States) that is possibly the second most familiar constellation in the sky. Practically every culture and country has a different name and myths connected with this group of stars.

In Hindu astronomy, it is referred to as Sapta Rishi, meaning the ‘Seven (Great) Sages’ and throughout eastern Asia, these stars compose the Northern Dipper and are colloquially known as the ‘Seven Stars of the Northern Dipper’. In Dutch, its official name is Grote Beer (Big Bear), but often called Steelpannetje (saucepan), because of its resemblance to one. In Finland the figure is known as Otava (salmon net) and widely used as a cultural symbol. In Hungary, it is commonly called Göncölszekér ("Göncöl's cart") after a figure in Hungarian mythology, a táltos who carried medicines in his cart that could cure any disease.[4]

The Great Bear, with its seven stars, is significant because the North Star (Polaris), the current northern pole star on Earth, can be found using it. Polaris is part of the ‘Little Dipper’, Ursa Minor. The Great Bear is made up from seven stars: Dubhe (124 light years away), Merak (79 yrs), Phecda (84yrs), Megrez (81yrs), Alioth (81yrs), Mizar (78yrs), Alkaid (101yrs). The first four of these make up the ‘pan’ or ‘body’ and the other three are the ‘handle’ or ‘tail’. If you draw an imaginary line from Merak to Dubhe and follow it on through the sky for about  five times the distance between them then the bright star you find is Polaris, the Pole Star.

The Planets

In the winter you can see the five brightest planets: Mercury, Venus, Mars, Jupiter and Saturn if you know where to look. Confusingly this changes according to the time of the year and sometimes they are too close to the sun to observe, so you are unlikely to see all of them on a single night. Saturn is particularly spectacular with its icy rings and Jupiter's red spot is easy to see with binoculars.

In the summer months you can see the Great Cluster in Hercules, a tightly knit group of about one million stars that appear like a faint ball of light. Also visible with binoculars is the Great Galaxy in Andromeda: a huge galaxy about 2.5 million light years from earth that can be seen quite clearly with a pair of binoculars.

Jo Macaulay

4 April 2016

By Jo Macaulay in Articles