Part 1: Signposts in the Sky
by Andy Gooden - March 2007
- The Plough
- A big kitten playing with a ball!
- The Hunter and his faithful hound
- Did you miss the eclipse?
- And Finally...
Have you ever looked up at the stars on a clear, dark night and thought, 'Oh my God! How on Earth am I supposed to find anything amongst that lot?' Well, join the club! If you are anything like I was just a short time ago, you will know that Cancer is lurking up there somewhere but you can't for the life of you see anything that looks remotely like a crab at all! Instead, all you can see is a jumbled mass of stars that don't look anything like the nice diagrams you've seen in all the books. Sound familiar?
This is the trouble everyone has to start with – many of the constellations don't actually bear much resemblance to the objects they are supposed to represent and often, even when you have found your target, you will have to use all your powers of imagination to understand what the people who named them in the first place were thinking of. 'Could we be witnessing the legacy of some ancient, mind-altering herb?' I often wonder! To complicate things even more, the Earth's rotation and its orbit around the Sun mean that the damn stars never seem to be in the same place, or the same way up, each time you look!
Anyway, don't give up just yet. The stars do helpfully remain in the same place relative to each other and by using a few of the more recognisable patterns as sort of 'inter-stellar signposts' it's easy to track down some of the more elusive objects.
I'm hoping these articles will form a kind of road map of the night sky and if my ramblings manage to inspire just one or two of you to venture outside on a freezing cold night to seek out some of the objects discussed here then I will consider this effort as time well spent.
In these articles I plan to concentrate on two or three constellations at a time. I will describe how to find and identify them, name one or two of the major stars and show how you can locate some of the other interesting objects lurking in their immediate vicinity. Most of the objects I'll talk about can be seen easily with the naked eye so the only specialist equipment you will need, (apart from some warm clothing and a clear, dark sky), will be your eyes. However, if you are lucky enough to be able to lay your hands on a good pair of binoculars these will greatly enhance the experience.
Time for a quick word of advice – Try to find as dark a spot as possible and don't go outside from a brightly lit house and expect to be able to see everything straight away. You need to give your eyes a chance to adjust to the dark for as long as possible - ideally for at least half an hour! So, make yourself as comfortable as you can and the longer you are out in the darkness the more you will see.
Living in the Northern hemisphere we are lucky enough to have at our permanent disposal a superb example of a stellar signpost. The pattern of stars commonly known as the Plough, (or 'Giant Saucepan' as my little niece prefers to call it), is actually the rump and tail of the vast Great Bear or Ursa Major constellation and is probably the most easily recognisable group of stars in the whole sky.
Using the stars of the Plough, imaginary lines can be drawn that make excellent paths to many other objects. Most famously, the two stars opposite the handle (or tail), Merak and Dubhe, often referred to as the 'Pointer Stars', can be used to locate Polaris, the North Star. Just extend the line formed by these two stars from the base of the 'pan' upwards until you find a lonely bright star. Congratulations! You have just found Polaris in the constellation of Ursa Minor or Little Bear.
If you watch this star for any length of time you will notice that all the other stars appear to rotate around this point. That's because Polaris is almost directly over the North Pole of the Earth's rotational axis. Hence it's name!
A big kitten playing with a ball!
Using the Plough as a starting point it is very easy to move on to the constellation of Leo. Imagine the Plough as a giant leaky saucepan – bear with me here. If you were to empty a huge tin of soup into this perforated receptacle, your tasty snack would run down the Great Bear's hind legs and pour onto the Lion's rear quarters. I know what you must be thinking now, 'He's obviously been sampling a few of those ancient herbs himself!' Trust me though, the more ridiculous you make these mental images the easier it will be to remember them.
The head of Leo forms a very distinctive shape. It looks like a giant reversed question mark and is often referred to as 'the Sickle'. The dot at the bottom of this back-to-front punctuation, (or the handle of the Sickle if you prefer), is a star called Regulus and at the tip of the Lion's tail is Denebola. From the Northern Hemisphere, Leo will dip below the horizon during the height of Summer.
I have chosen Leo as one of our first stopping off points because of the rare treasure that seems about to be swallowed up by its huge jaws. Saturn is the real 'Jewel' of our Solar System and is, even as I write this, perched perilously close to the end of Leo's nose. One playful swipe from a huge paw and it would be gone forever!
To the naked eye Saturn looks like a very bright star but a decent pair of binoculars will reveal tantalising glimpses of the planet's famous rings and even a modest telescope will provide a spectacular view of this gassy giant. If you get a chance to see Saturn through a telescope at the moment, grab it as the tilt of the planet is causing the rings to close up as we see it from the Earth and by 2009 they will be completely edge-on to us rendering them invisible to all but the most powerful optics. Don't panic though, they will start to open up again after 2009 and this beautiful planet will be restored to its former glory once again.
The Hunter and his faithful hound
I couldn't end this first instalment without paying a visit to one of the most spectacular constellations of all. The stars that form the body of Orion make almost as familiar a pattern in the sky as the Plough but, as with the Plough, this is only part of the complete constellation and the brighter, dismembered body is often thought to be all there is to it. Take a closer look though and you will notice the raised right arm - possibly trying to grasp one of Taurus, The Bull's horns - and the curved bow held in his other hand.
If you are having trouble finding Orion, locate Leo using the method above and follow his gaze through about 90 degrees to your right. If you are lucky you will now be face-to-face with the Great Hunter himself.
Orion is a Winter constellation for the Northern hemisphere and it will shortly disappear from the night sky altogether. It will re-emerge again in the Autumn, reaching its highest point in the sky in December. During March though you should be able to see Orion up until around 10pm.
Perched on Orion's right shoulder is the famous red giant, Betelgeuse. Have a good look at this star - it really is very red! Another famous star, Rigel marks his left foot but I really want to draw your attention to the sword. These stars are a bit fainter than the rest but are by no means less interesting. Take a closer look at the middle star of the three for instance. Does it look a bit fuzzy to you? That's because you are in fact looking at M42, the Great Orion Nebula. This huge cloud of cosmic dust is a special kind of nebula known as a 'stellar nursery' and acts as a massive birthing pool for new stars. It is one of the few nebulae that can be seen with the naked eye.
Orion actually contains many more nebulae, including the famous Horse Head Nebula and the Running Man Nebula but, sadly, they are far too faint to be seen without the aid of a powerful telescope.
The three stars of Orion's belt can be used as a handy pointer to find another couple of very special objects. Firstly, drawing a line through the belt and extending it out to your left will take you to the brightest star in the whole sky. This is Sirius, the Dog Star, in Canis Major and is supposed to mark the chest of the beloved hound as it leaps playfully at the Great Hunter's feet! Go on - use your imagination!
Now extend the line through Orion's belt in the opposite direction, curving it very slightly upwards and you will come to another red giant star called Aldebaran at the base of the first of Taurus' horns. Because of its position and colour Aldebaran is often referred to as the 'Bull's Eye'. Straighten the line out again and extend it a little further to the other side of Taurus and you will find M45, more commonly known as The Pleiades or 'Seven Sisters'. This is a beautiful little cluster of stars that will look stunning when viewed through a pair of binoculars.
Did you miss the eclipse?
On 3rd March this year we were treated to a total lunar eclipse where the shadow of the Earth completely covered the surface of the Moon. For anyone who was unfortunate enough to miss this fantastic spectacle I have included this wonderful series of photographs taken by Nick King
, an expert astro-imager, that illustrate beautifully how the Moon's appearance changed during the event. A big "thank you" to Nick for allowing me to use this image.
I hope you have enjoyed this first little jaunt around the stars. If you try to find any of the objects I've mentioned please let me know how you get on. If you have any comments or suggestions about the article they will be very welcome or if you have a favourite object or constellation you would like discussed in a future issue do let me know! You can contact me via the 'Contact' link at the top of this page.
Amongst the planned destinations next time will be two mythical beauties of the sky – Queen Cassiopia and her daughter, the Princess Andromeda. But I can assure you, dear reader, all is not sweetness and light with these two. What terrible fate could one of these sirens have in store for us? Don't miss the next issue for the full terrifying story!
Here's a little teaser question for you before I wrap up. How many planets have been discovered in our Solar System to date? I'm feeling generous so I'll allow two possible answers. But, here's a clue... neither of them is 9!
- Some useful links to finish:
- A great Interactive sky map
- Scibermonkey - The Solar System and Beyond
- The BBC's space pages
- UKAI - The forum where all the great Astro-Imagers meet
- Detailed information on the constellations