Constellations, Constellation of Stars, Astronomy & Constellations, Astrology & Zodiac Signs (For CBSE, ICSE, IAS, NET, NRA 2022)

Glide to success with Doorsteptutor material for competitive exams : get questions, notes, tests, video lectures and more- for all subjects of your exam.


  • On a clear moonless night, we can see thousands upon thousands of stars dotting the night sky.
  • If we are creative, we can imagine shapes and patterns these stars can make.
  • Some of these patterns made up of groups of bright stars are easy to recognize and we can call this groups as a constellation.

Some Constellations

Some Constellations
  • The ancients named many of these recognizable constellations after the objects or animals they resembled and they built stories around them too.
  • For example, the constellation Perseus, Andromeda, Cetus, Cassiopeia, and Pegasus are all linked to the mythology of the Greeks.
  • Common constellation names are similar across cultures such as Pisces – the fish in Greek is also called Meena (also meaning fish) in Sanskrit.

Constellation of Stars

Constellation of Stars
  • All the constellations appear to move in the sky from west to east because the earth rotates from west to east.
  • Also, all constellations in the southern hemisphere are not visible in the northern hemisphere and vice versa.
  • The reason is the earth is round and some constellations do not fall in the line of sight. A person in the equator can see almost all the constellations.

Astronomy & Constellations

  • In astronomy, the degrees of longitude marking each zodiac constellations are not equally sized.
  • So, the number of days the Sun spends in each zodiac constellation varies accordingly.
  • This can be seen in the following list (days in brackets) , which includes an unofficial thirteenth zodiac constellation called Ophiuchus, whose modern boundary also intersects the ecliptic:
    • Sagittarius (32) ;
    • Capricornus (23) ;
    • Aquarius (24) ;
    • Pisces (38) ;
    • Aries (25) ;
    • Taurus (37) ;
    • Gemini (31) ;
    • Cancer (20) ;
    • Leo (37) ;
    • Virgo (45) ;
    • Libra (23) ;
    • Scorpius (7) ;
    • Ophiuchus (18) .

Astrology & Zodiac Signs

  • In astrology, the zodiac constellations familiar to us as astrology signs are neatly divided into 12 segments of sky 30° of longitude wide.
  • Sun then spends around one month in each of the zodiac signs as it makes its annual trek across the sky.
  • A person՚s ‘star sign’ is determined by which zodiac constellation the Sun is in front of at the time of their birth
  • But since the Sun appears in front of a zodiac constellation during the daytime, the sight is obscured from view.
  • If we Can see the stars during the daytime, though, we would see the Sun slowly drift from one zodiac constellation to the next over time, as it completes one full circle around the sky every year.
  • The zodiac constellation the Sun appears in front of during any month no longer corresponds to the horoscope dates one reads about in the newspapers due to precession.

Big Dipper

Big Dipper
  • The big dipper also called as Saptarishi in India is a group of seven stars visible in the northern hemisphere.
  • This constellation looks like a big ladle or like a wheel barrow and is part of a bigger constellation called Ursa Major (The great Bear) .
  • Two of the stars on this constellation appear to point to the pole star (Polaris/Dhruva) .
  • The pole star is the only star in the sky that does not appear to move east to west but appears fixed.
  • So, it is directly above the earth՚s axis.


The Hunter or Mriga in India
  • This constellation known as ‘the hunter’ or Mriga in India. It has many bright stars in it.
  • Three bright stars are in line make up the “belt” of the hunter. These three stars point to the brightest star in the night sky – Sirius.

Developed by: