Starlit Sky: 8. Auriga

continued from Starlit Sky: 7. Canis Minor


 

Now it is time to find some other constellation.

Do you remember Taurus? The constellation of the bull? To refresh, go to Starlit Sky: 5. Taurus and Pleiades.

Here we know the bright star Aldebaran, the eye of the bull and the horn of the bull Elnath.

Now Elnath forms a part of another constellation called Auriga. Let us now identify it.

 

Auriga:

auriga 1

Move northwards from Aldebaran. You will notice a brilliant bright star. That star is called Capella. Once you find Capella, try to find less brighter 4 stars as shown in the figure. Include Elnath too into the mix. Now you have a sort of a pentagon like figure. That is Auriga constellation.

Simple isn’t it?

Auriga is called Ratha saarathi mandalam in Sanskrit.

We imagine a man carrying a goat (Capella being the goat) as Auriga. See figure below for more clarity.

auriga 3

 

Auriga is Latin for charioteer. It is associated with mythological charioteers from Greek mythology.  Auriga is prominent in the northern hemisphere. It can be seen in its entirety in the southern hemisphere only upto 34 degrees.

The Greek hero Erichthonius, who was brought up by goddess Athena, is credited to be the inventor of the chariot.

auriga 2

 

This is not the only myth to be associated with the constellation. Even in Greek mythology, this constellation has many stories attached to it. But essentially, it is charioteer, with a goat on his left shoulder and 3 kids near the goat.

 

Capella:

Capella, also called alpha Auriga, is the brightest star in the constellation, with magnitude of 0.08. It is the 6th brightest in the night sky. It is depicted as the goat, Amalthea, who suckled infant Zeus.  It is relatively near us, only about 43 light years away.

Though it looks like a single star, it is a cluster of 4 stars, in a set of 2 binary pairs. One pair of Capella system are yellow super giants about two and half times bigger than Sun. They are called Capella Aa and Capella Ab. Capella Aa has exhausted its share of hydrogen and is now fusing helium to form carbon and oxygen in its core. Capella Ab is slightly smaller and hotter than Aa and is on its way to become a red giant.

The other pair of the Capella system are called Capella H and Capella L. These two are fairly faint, small and cool red dwarfs.

Did you know that the Capella system is one of the brightest sources of X-rays in the sky? Amazing!! These are thought to be coming from the corona of the massive super giant star.

 

Here is a comparison of the sizes of the Capella system to our Sun.  The small bright yellow dot is our solar system.  See how small we are in comparison!!

Capella-Sun_comparison

 

Other stars of the constellation:

To the left of Capella is Beta Auriga. It is also called Menkalinan, an Arabic origin name, meaning the “shoulder of the charioteer”.  It is 81 light years away and has a magnitude of 1.90.

Gamma Auriga, is Elnath, the one we started with. Originally, it used to be thought of as a part of both constellations, but now modern scientists keep Elnath with Taurus.

Epsilon Auriga is the star that is towards the right of Capella. It is also called Al Maaz. It is an eclipsing binary star.

Random gyaan:

A binary star system is when two stars go around each other. But if a binary star is directly in our line of sight, then these two stars appear to go across each other periodically. They essentially eclipse each other from our eyes. That’s why they are called eclipsing binary stars. We can detect such eclipsing binaries only when their luminosity changes during the eclipses and during transit.

 

Hope you had as much fun as I did finding Auriga. See you next week with more.

 

Disclaimer: I have taken the figures from the Google images. The copyrights belong to the originators.


to be continued……………..

 

 

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