Constellations

The most beautiful view according to me is of the NIGHT SKY! I think that a sky full of stars is the most perfect view one can get from EARTH.

If anyone wants to experience it then, he/she must travel to a DARK PLACE and just look up. It’s MAGNIFICENT!

 

Okay, so even if we look up now and let’s say that the sky is CLEAR (which is not always the case), we may able to see some patterns formed by the stars, which is a human tendency. We humans have a unique quality where we can find a pattern in everything.

But, now the question is, DOES THIS PATTERN REALLY EXISTS? The answer is pretty simple: NO, IT DOESN’T. The main reason why we see such patterns is that the sky perceived by our eyes is in 2D and so, we see all the stars to be in the same plane and then we just connect them as we connect the dots on a paper to form patterns. We may say them to be illusions. If we go and see there, there won’t be any patterns as the stars are at different distances.

So, let’s see how the constellations were formed. In the ancient times people existed in the form of apes and then slowly evolution took place. In short, their brains evolved, they started to think, question and to look up. They tried to make sense out of what they were seeing, they started connecting the stars and making patterns out of it. And besides at that time there were no equipments and technologies that may stop people from looking up (just kidding). So, only thing they could do at night was to look up and make patterns which may resemble to some tools or animals.

As, these patterns existed, eventually stories came by, which told why these patterns are present. People like to tell stories, don’t they? Similarly, at that period too, stories were being made. Their vast imaginations gave birth to some myths and legends. This is how constellations were formed.

Constellations were helpful for people in various ways like to mark directions, know about which season is coming up next and many more. In the past ages there were no compasses to guide the voyagers, their only hope was constellations which showed them directions. Constellations were helpful to determine the seasons as well as for time keeping practices (months, year). Even today we refer constellations to determine the end and start of the month.

We have a total of 88 constellations and these are universally accepted. In the year 1928, IAU (International Astronomical Union) confirmed these 88 constellations and divided the celestial sphere into 88 different regions. Each region is a part of the celestial sphere covered by a constellation and its boundaries are marked using the Right Ascension- Declination coordinate system. The word “CONSTELLATION” originates from a Latin word “CONTELLACIO” which means a set of starts.

 

Now, we know about constellations. So, let’s move further. Constellations are of 3 main types: Circumpolar, Zodiacal and Seasonal.

Circumpolar-

The constellations which don’t set or go below the horizon are known as “Circumpolar” constellations. As, we all know that the constellations are seemed to revolve around the pole star POLARIS (Ursa Minor) in circles. These types of constellations vary from place to place. But, still taking an average, we find that there are 5 such constellations: Ursa Major, Ursa Minor, Cassiopeia, Cepheus and Draco.

As mentioned before, these constellations vary from place to place, this is because for a person from North Pole, no constellation is going below the horizon. This means that all constellations which are possible to be seen from the North Pole are all circumpolar constellations.

 

Zodiacal-

The constellations which form the ecliptic are known as the “ZODIACAL” constellations. Ecliptic is the path traced by the Sun on the celestial sphere. There are 12 zodiacal constellations and also revolution period of the Earth is 12 months. This means that Sun is in 1 constellation for a period of 1 month.

12 Zodiacal constellations: Capricornus, Cancer, Gemini, Virgo, Scorpius, Leo, Pisces, Aquarius, Sagittarius, Aries, Libra, Taurus.

 

Seasonal-

As, we know that the constellations are revolving around the Pole Star Polaris (Ursa Minor) and depending on location we are able to see few constellations. The ones which we are unable to see are simply below the horizon. We also see semi-circular tracks formed by these constellations, this means that remaining part of the circle to be traced is below the horizon and therefore we see the constellations rise and set.

If we observe the constellations from a same location over a year then, we could be able to make a pattern of the constellations which are only visible for certain months. These constellations are known as the “Seasonal” constellations. We have 4 different seasons, which also means that we have 4 different types of seasonal constellations: Summer, Winter, Fall, Spring.

Now, we know 3 main types of constellations. There are 2 more types of constellations which we call 2 sub-types of constellations. 2 sub-types: Northern constellations and Southern constellations. It’s pretty easy to guess that the constellations viewed from one pole are definitely different that the constellations viewed from the other pole which is opposite to it. For example, consider 2 persons standing with their backs pointing each other, so the view seen by one person won’t be seen by the other one and vice-versa.

Okay, so we have Northern and Southern constellations and not Eastern and Western constellations. Why don’t we have them? They are two opposite points, but still we don’t have Eastern and Western constellations. The reason is that the constellations rise in the East and set in the West, this means that the constellations seen from the same latitude will always be the same, no matter at which point 2 persons are standing as long as they both have same latitude.

Northern Constellations-

We are lucky enough that we have our North Pole pointing nearby to a star. This means that Pole Star isn’t stationary but it also performs a small circle around our North Pole, but as the radius of this circle is really small that we consider the Pole Star to be stationary at the North Pole. The constellations which are visible between the Equator and the North Pole are known as the “NORTHERN” constellations.

 

Southern Constellations-

We don’t have any pole star for South Pole. This is because there is no star present at the location where our South Pole points. The constellations perform circles around the South Pole as they do around the North Pole but the only difference here is that there is no pole star for South Pole and the constellations are different.

The constellations which are visible between the Equator and the South Pole are known as the “SOUTHERN” constellations.