KERALA PSC / ASTRONOMY / UNITS OF MEASUREMENTS IN ASTRONOMY / NOTES

 

KERALA PSC / ASTRONOMY / UNITS OF MEASUREMENTS IN ASTRONOMY / NOTES

KERALA PSC / ASTRONOMY / UNITS OF MEASUREMENTS IN ASTRONOMY / NOTES

 

·       Astronomical Unit:

An astronomical unit is the mean distance between the earth and the sun and is estimated to be 150 million kilometers. Astronomical Unit (AU) is used in the distance measurement of solar system.

Ø A light year = 60000 astronomical units

 

·       Light Year:

A light year is the distance travelled by light in one year at the speed of about 300000 km/second. Light years are used to measure the distance between stars, galaxies etc…

 

·       Parsee:

A parsec is a unit of distance equal to 3.26 light years.

Ø One kiloparsec = 3000 light years

Ø One mega parsec = 1000 kiloparsec

 

·       Parallax:

A parallax is the unit used for calculating the distance of nearest objects within 15000 light years

 

·       Lephied Variables:

Lephied variables are used to measure the distance of objects up to 10 million light years

 

·       Cosmic Years:

Cosmic years is the period by which the sun completes one revolution round the galactic centre of milky way.

1 Cosmic Year = 250 Million years

 

KERALA PSC / ASTRONOMY / UNITS OF MEASUREMENTS IN ASTRONOMY / NOTES