Assume that a typical galaxy contains about 200 billion stars and that there are more than 150 billion galaxies in the known universe. Estimate the total number of stars in the universe.

Q: If the active core of a galaxy contains a black hole of 106 MSun , what will the orbital distance be…

A: Given: The mass of the black hole is 106 MSun. The orbital period is 1 hr.

Q: Pls help ASAP. Pls show all work.

A: Given  r = 30 kpc Velocity curve To find out  Total mass of the galaxy ( estimated )

Q: e gravitational energy of a pair of colliding galaxies , each of mass 10 Mo separated by a distance…

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Q: Let us assume that our galaxy consists of 2.5 × 1011 stars each of one solar mass. How long will a…

A: Mass of the galaxy is

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: 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: what is the difference between a Sa and a Sb galaxy? Between a SBb and a Sb?

A: Galaxy morphological classification is formed by the division of the galaxies into groups on the…

Q: what are some fundamental properties of late type galaxies that our theories of galaxy formation…

A: All those galaxies which are included under Spiral and Irregular Galaxies are termed as Late Type…

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: Let's say that the number density of galaxies in the universe is, on average, 3 × 10–68 galaxies/m3.…

A: Given :number density of galaxies, n = 3 × 10–68 galaxies/m3            Observable distance by…

Q: the sun has an orbital speed of about 220kms^-1 around the centre of the galaxy , whose distance is…

A: orbital speed of sun = 220 kms= 220000 msdistance = 28000 light years

Q: why are the shells visible around some elliptical galaxies significant?

A: The shell structures in the elliptical galaxies indicates the extremely low surface brightness and…

Q: A star at a distance of 50000 light years from the center of a galaxy has an orbital speed of 100…

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Q: Describe the age and temperature of stars that make up spiral galaxies and their location.

A: A galaxy can be bombarded by other, smaller galaxies. Even if a galaxy is isolated, internal…

Q: Astronomers frequently say that "there are more stars in the universe than there are grains of sand…

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Q: What is the ratio of the distance to the nearest galaxy to the size of the Milky Way galaxy? This is…

A: Given information: The diameter of the milky way (dMW) = 1021 m The distance of the nearest galaxy…

Q: You observe a star orbiting in the outer parts of a galaxy. The distance to this galaxy is known,…

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Q: A star at a distance of 50000 light years from the center of a galaxy has an orbital speed of 100…

A: Distance of the star from the center of the galaxy, r = 50000 ly The orbital speed of the star, v =…

Q: Based on the value you have found in problem 3, if the mass of the Sun is about 2.0 x 1030 kg, what…

A: Given data The mass of the sun is given as ms = 2 x 1030 kg. The value found in the previous…

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: Is the NGC 4440 galaxy observable from the Calar Alto Observatory?

A: Calar Alto Observatory Calar Alto, a 2,168-meter-high (7,113-foot) mountain in the Sierra de Los…

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

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Q: If astronomers were to find they have made a mistake and our solar system is actually 7.8 (rather…

A: Let m be defined as the mass of the sun, and M be defined as the mass of the galaxy. Since the sun…

Q: Assume that the average galaxy contains 1011 MSun and that the average distance between galaxies is…

A: The average density of matter in galaxies is ρ=mV=m43πr3=1011Msun43π10 millionlightyears×9.46×1021…

Q: How long ago was that galaxy right next door to our own Galaxy if it has always been receding at its…

A: The distance is 235 million light-years. The velocity is 4817.5 km/s.

Q: Astronomers observe several galaxies in the Local Group that actually approach the Milky Way. The…

A: Andromeda galaxy is the nearest galaxy to our Milky Way galaxy. It is approximately 2.5 million…

Q: A galaxy's velocity is measured to be 3112 kilometers per second away from us. What is the distance…

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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: Suppose you have obtained spectra of several galaxies and have measuerd the observed wavelength of…

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Q: What is the difference between an E7 and E0 galaxy?

A: Explanation: Elliptical galaxies have a very large range of sizes. Most of their stars are old and…

Q: If a galaxy has a radial velocity of 21,641 km/s, what is its expected distance from the Hubble Law?…

A: Given data :  Radial velocity of galaxy (V) = 21,641 km/s Humble constant (Ho) = 71 km/s/Mpc…

Q: what is the difference between an E0 galaxy and an E1 galaxy?

A: An elliptical galaxy has approximately ellipsoidal shape and a smooth, nearly featureless image.…

Special Relativity

The theory of special relativity discusses how space and time are related to objects traveling along a straight line at a constant speed. Simply stated, as an object reaches the speed of light, its mass becomes infinite and it is unable to move faster than light. This interstellar speed limit has been the topic of much debate in astronomy, and also in science fiction when people consider how to fly over large distances.