how long do long-exposure photos of two selected areas of the sky reveal that galaxies are very common?

Q: Using 22 km/s/million light-years for Hubble’s constant, what recessional velocity do we expect to…

A: Given  Hubble's constant , H = 22 km/s/ million light years. Distance of galaxy , d = 600 million…

Q: A starburst galaxy produces only 50 new stars per year. (True or false)

A: A starburst galaxy is known for its high rate of star formation in comparison to the other galaxies.…

Q: how do deep images by the Hubble Space Telescope confirm the bottom-up theory of galaxy formation?

A: The bottom up model, also known as Hierarchal Clustering s the most accepted way for galaxy…

Q: If a group of galaxies is revolving around its center at 240 miles/sec how fast is it moving in…

A: Let the galaxy's speed be denoted by v. The speed of the galaxies is 240 miles per second.

Q: In the image below you see two interacting galaxies; one is nearly face -on and the other is nearly…

A: The shape of the galaxies says the evidence of the tidal disruption.

Q: how might you be misled if you studied only the brightest galaxies in a cluster?

A: There are some of the observations which may mislead if you studied only the brightest galaxies in…

Q: why do you have to know the distance to a galaxy to find its mass?

A: The orbital motion of stars explains the masses of galaxies. The stars in a heavier galaxy exhibit…

Q: Explain how the temperature of hot gas can be used to find out about the gravitational pull of a…

A: Given: The hot gas temperature which is used to find the gravitational pull To find: The explanation…

Q: A galaxy is 30 Mpc away from us and has a recession velocity of 2000 km.s-1 . What is Hubble’s…

A:

Q: which galaxies are poorest in gas and dust? Which have the fewest bright stars?

A: Elliptical galaxies contains primarily old stars and they do not have much gas and dust. The…

Q: propose an explanation for the lack of gas, dust, and young stars in elliptical galaxies.

A: The elliptical galaxies are old and dim galaxies. The stars in the elliptical galaxies give out red…

Q: Which galaxies are moving the fastest away from us?

A: Our nearest galaxy is Milky way.

Q: A galaxy's distance from us is measured to be 49 Mpc. Using the same value of the Hubble constant,…

A: A megaparsec is given by 1 Mpc = 3 x 106 light-years). This means that a galaxy 1 megaparsec away…

Q: Observations of quasars have shown us that many are extremely _________, emitting more energy than…

A: Required : Fill in the gaps.

Q: Which of the following is an accurate statement about quasars?

A: ANS: They are abnormally massive, luminous stars at the cores of ancient galaxies.

Q: Why aren’t the fluctuations there in the formation of Galaxies and other similar entities?

A: Galaxies and the other similar entities could not be without the existence of fluctuations in the…

Q: What does the redshift of the galaxies tell us about their motion with respect to the Earth?

A: The displacement of the spectrum of an astronomical object toward longer wavelength (red) due to the…

Q: how many Galaxy are there in all?

A: The huge collection of gas, dust, and billions of stars and their stars, which are held together by…

Q: True or False: Dwarf elliptical galaxies and giant ellipticals probably formed in entirely different…

A: To find true or false: Dwarf elliptical galaxies and giant ellipticals probably formed in entirely…

Q: How would our knowledge about galaxies be altered if we didn't have telescopes? Justify your answer.

A: If we did not have telescopes, it would be impossible to see other galaxies by naked eye, hence we…

Q: ring galaxies often have nearby companions. What does that suggest?

A: The origin of ring galaxies is often debated. Some scientists believe that ring galaxies have formed…

Q: you will compare the balloon to our universe, with the dots / markings as galaxies or galaxy…

A: The balloon is compared to the universe and the dots are compared to the Galaxies, then When the…

Q: If a galaxy is 18 Mpc from Earth and the Hubble constant is 70 km/s/Mpc, what is the recession…

A: Answer:-  Answer (1)  Given  Distance (d) = 18 Mpc  Hubble constant (Ho) = 70 km/s/Mpc  Velocity of…

Q: Identify a feature of the Whirlpool Galaxy that is visible in all several types of light. Explain…

A:

Q: What is formation and motion of galaxies?

A: Formation of galaxies:           Galaxies are collections of stars, gas, dust and dark matter held…

Q: how far away is the galaxy

A:

Q: In the reading, you were told that there were roughly 10,000 galaxies in the image of the Hubble…

A: Given:  one image of hubble ultra deep field is roughly 10 square arcminutes.  Number of galaxies in…

Q: what evidence is there that galaxies collide and merge?

A: The delicate distribution of matter in the galaxies causes the galaxies to collide and is said as…

Q: Assume that a typical galaxy contains about 200 billion stars and that there are more than 150…

A: Given, a typical galaxy contains about 200 billion stars and that there are more than 150 billion…

Q: what evidence is there that galaxies contain dark matter? Supermassive black holes?

A: By the studies of rotation of galaxy, astronomers estimate that the 10% mass of galaxy is in the…

Stellar evolution

We may see thousands of stars in the dark sky. Our universe consists of billions of stars. Stars may appear tiny to us but they are huge balls of gasses. Sun is a star of average size. Some stars are even a thousand times larger than the sun. The stars do not exist forever they have a certain lifetime. The life span of the sun is about 10 billion years. The star undergoes various changes during its lifetime, this process is called stellar evolution. The structure of the sun-like star is shown below.

Red Shift

It is an astronomical phenomenon. In this phenomenon, increase in wavelength with corresponding decrease in photon energy and frequency of radiation of light. It is the displacement of spectrum of any kind of astronomical object to the longer wavelengths (red) side.