A Constellation is a group of stars that resemble a pattern from which legends and stories have been built around. The constellations that most people are familiar with are those of the Zodiac and they include Leo and Libra. Leo and Libra for instance are based on the Ancient Greek Legends.
The Chinese had their own constellations that were Azure Dragon of the East, Black Tortoise of the North, White Tiger of the West and Vermillion Bird of the South. When constellations are mentioned, this site refers to the Greek constellations unless stated.
Below is the complete list of 88 constellations that surround our solar system. If we went to a different star such as Rigil Kentaurus also known as Alpha Centauri, the stars will not appear in the same place in the sky as they do on Earth. The constellations that surround Rigil Kentaurus will have a different shape and so will need new constellations. The original list of constellations consisted of 48 which was devised by Greek astronomer Ptolemy in 140AD. During the 19th and 20th, they swelled in numbers to 88, some of the newer constellations were divised by Nicolas L de LaCaille, which are predominantly located in the southern hemispheric constellation.
To get a rough idea of which are new and which are old, the constellations in the southern hemisphere with a few exceptions are new. The Microscopium and Telescopium are two that are definitely new as the objects they represent were not around in 140AD.
Some constellations are easy to identify such as Ursa Minor and Orion whilst others are hard to distinguish between them and any other collection of Stars, e.g. Telescropium because it is simply two stars in a line.
Some constellations have been dropped such as Quadrans Muralis (Mural Quadrant) and all that remains of this constellation is the Quantratids, a Meteor Shower that is within the Bootes constellation boundary now.
As the Sun orbits round the Galactic Centre, the stars will move out of place and so these constellations won't be recognisable in thousands of years time. Ursa Major will probably look more like a tadpole than what it does now, a saucepan.
Since the Zodiac Constellations were drawn up, they are no longer in the positions that they are associated with. For example, the Leo Constellation doesn't appear after the Sun sets in August anymore. It was Edmund Halley, Sir who discovered that stars moved and it is on that basis Journal of Astronomical Heritage that we now that these constellations won't be like this in say 50,000 years.
Some stars such as Nunki will move out of position they are now quicker because they are in Sagittarius and closer to the galactic centre than say Acubens in Cancer which by rough calculation is further out of the galaxy than our own Sun. In the future, they'll be new constellations, maybe a computer constellation or a plane.
Long before the times of G.P.S., ships and travellers would have had to rely on constellations and stars to know where they were going. The single most important constellation was Ursa Minor and Polaris, the Pole Star. You'd be able to use the Pole Star as a fixed point in the sky as it was always above the North Pole. This wouldn't work in the southern hemisphere as you wouldn't be able to see Polaris, they'd be some other constellation or star to which to base your navigation on. There is no southern pole star, the closest to that title is Polaris Australis. Ref: N.A.S.A
Polaris was not always the Pole Star, in 3000 B.C., Thuban in the constellation of Draco was the Pole Star. In 13,000 years from now, the Pole Star will be Vega and then in another 13,000 years after that, Polaris retains that title. A long time away and no need to recalculate any equipment just yet.
Adventurers still use the constellations as a guide so when the GPS fails or the compass breaks, the constellations will still be there and you can know where you are going.
The largest constellation in term of area allocated to the constellation is Hydra, the mythical multi-headed creature. It takes up about 3% of the night sky in the southern hemisphere. The largest Zodiac constellation is Virgo which takes up a 3.14% of the night sky so not much smaller than Hydra. The largest constellation in the Northern Hemisphere as the other two are Equatorial and Southern is Ursa Major the Great Bear with 3.1% of the night sky.
On the other extreme, the smallest constellations by area size percentage are Crux, the southern cross and Equuleus where each take up a mere 0.17% of the sky as a percentage. The smallest Zodiac constellation is Capricornus, the Sea Goat which takes up 1% of the night sky. Although it is smallest zodiac constellation, it is still larger than a lot of other constellations, Capricornus is the 40th largest constellation out of the 88 constellations and is the only constellation with a whole number area percentage.
A Zodiac constellation is a constellation that appears after the Sun goes down. It covers an area 8° north and south of the celestial ecliptic. There are thirteen signs that fall into this space but only twelve are widely recognised as bein in the Zodiac.
Zodiac Signs are used in Horoscopes to forecast a persons fortune for a day, a month and sometimes a year ahead. There are twelve officially recognised Zodiac constellations by most astrologers. Astronomers argue that there are in fact 13, the thirteenth being Ophiuchus, the Serpent Holder. I have covered the arguments for and against on my Ophiuchus page.
As the Sun moves across the sky, it becomes a member of a number of constellations but because the Sun outshines the all the stars, we don't see them. Its more correct to say as the Earth revolves, the Sun would appear to be a member of a series of constellations. The only constellation that the Sun is a member of that we are interested in is the sign that it sets in for astrologers. Therefore the correct answer is that the Sun is not a member of a constellation in the same way that Regulus is a member of the Leo constellation.
If we are at the Galactic Centre and looked back at the Earth, the Sun would probably look as though it was a member of the Gemini or Auriga constellations. If we were at that spot on the borders of Gemini and Auriga and looked back at the Sun, we would possibly see that the Sun is in Sagittarius. Likewise if we moved round the galaxy, the Sun would be a member of a different constellation. It'll be in a different constellation depending on where we are.
If we were on a space ship near Rigil Kentaurus, the nearest yellow star like our Sun and we wanted to come back, we would head towards the an area near Caph also known as Beta Cassioepieae. Our Sun would appear in a different constellation in different positions of viewing.
|Canes Venatici||Canis Major||Canis Minor||Capricornus|
|Coma Berenices||Corona Australis||Corona Borealis||Corvus|
|Triangulum Australe||Tucana||Ursa Major||Ursa Minor|