Tag: constellations and galaxies

Questions Related to constellations and galaxies

Fill in the blank:

Ursa Major: _________ :: Orion: Hunter

geography constellations and galaxies constellation different constellations and galaxies milky way

  1. Big Dipper

  2. Leo Major

  3. Great Bear

  4. Saptarshi

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Correct Option: C
Explanation:
Orion, due to its appearance, is known as Hunter. Similarly, due to its appearance, Ursa Major is known as Great Bear.

Fill in the blank:

The 3 middle stars in Orion represent the ________.

geography constellations and galaxies constellation different constellations and galaxies milky way

  1. belt of the bear

  2. belt of the hunter

  3. tail of the bear

  4. stick of the hunter

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Correct Option: B
Explanation:

Constellations were phrased by ancient people to enable easy recognition of stars. Constellations resemble objects that were familiar to those people. Orion resembles the hunter, and the 3 middle stars of the constellation represent the belt of the hunter.

What is a group of stars in the sky that form an imaginary picture ? 

geography constellations and galaxies constellation different constellations and galaxies milky way

  1. Solar System

  2. Moon

  3. Constellation

  4. Galaxy

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Correct Option: C
Explanation:

Group of stars in the sky that form an imaginary picture is called constellation there are various constellation in the sky.

Star Sirius, belongs to constellation named :

geography constellations and galaxies constellation different constellations and galaxies milky way

  1. Taurus

  2. Aquarius

  3. Canis Major

  4. Orion

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Correct Option: C
Explanation:

Sirius star is the most brightest star and it belong to the Canis Major Constellation.

The distance of a galaxy from the earth is of the order of $10^{25}$ m. The time taken by light to reach the earth from the galaxy is

physics constellations and galaxies light year evolution and end stages of stars in the world of stars

  1. $3 \times 10^{14}$ s

  2. $3 \times 10^{16}$ s

  3. $3 \times 10^{18}$ s

  4. $3\times10^{20}$ s

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Correct Option: B
Explanation:

Speed of light, c = 3 x 10$^8$ m s$^{-1}$
Time taken by light to reach the earth from the galaxy is
$\displaystyle t = \frac {10^{25}m}{3\times 10^8m\,s^{-1}}\,=\,3\times 10^{16}s$

The $6563 A^0 H _\alpha$ line emitted by hydrogen in a star is found to be red-shifted by $15 A^0$. The speed with which the star is receding from the earth is

physics constellations and galaxies light year evolution and end stages of stars in the world of stars

  1. $3.2 \times 10^5m s^{-1}$

  2. $6.87 \times 10^5m s^{-1}$

  3. $2 \times 10^5m s^{-1}$

  4. $12.74 \times 10^5m s^{-1}$

Show answer
Correct Option: B
Explanation:

Wavelength of $H _\alpha$ line, 
$\lambda=6563A^o$
$=6563\times10^{-10}$


Redshift observed in star $(\acute{\lambda-\lambda})=15A^o=15\times 10^{-10}$

Let the velocity of the star with which it is receding away from the earth be v.
Red shift relation, $\acute{\lambda}-\lambda$=$\dfrac{v}{c}\lambda$

$=\dfrac{c}{\lambda}\times (\acute{\lambda}-\lambda)$

$=\dfrac{3\times 10^8\times 15\times 10^{-10}}{6563\times 10^{-10}}$
$=6.87 \times 10^5m s^{-1}$

The Milky Way Galaxy is about

physics constellations and galaxies light year evolution and end stages of stars in the world of stars

  1. 150000 light years

  2. 200000 light years

  3. 250000 light years

  4. 170000 light years

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Correct Option: A
Explanation:

Milky way is about 100,000 light years or 30kpc.

The Milky Way Galaxy is about 150000 light years

What is known as Astronomical Unit (AU)?

physics constellations and galaxies light year evolution and end stages of stars in the world of stars

  1. Average distance between Earth and Sun

  2. Average distance between Sun and Moon

  3. Average distance between Moon and Earth

  4. Average distance between Earth and Star

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Correct Option: A
Explanation:

Average distance from the centre of the Earth to the centre of the Sun forms the astronomical unit (AU). It equals to around 149.6 million kilometres.

Which method is used by astronomers to calculate how far the star is?

physics constellations and galaxies light year evolution and end stages of stars in the world of stars

  1. Parallax

  2. Equillax

  3. Purplex

  4. None

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Correct Option: A
Explanation:

Parallax is used by astronomers to measure the distance between the stars. Parallax is also known as trigonometric parallax.

1 Parsec is:

physics constellations and galaxies light year evolution and end stages of stars in the world of stars

  1. 2.3 light years

  2. 3.3 light years

  3. 4.3 light years

  4. 5.3 light years

Show answer
Correct Option: B
Explanation:

Parsec is a unit of length used in astronomy to measure distances outside our solar system. One parsec equals to around 3.26156 light years.