How do astronomers measure the mass of a galaxy?

The mass of the Galaxy can be determined by measuring the orbital velocities of stars and interstellar matter.

How do astronomers measure the distance of galaxies?

Astronomers estimate the distance of nearby objects in space by using a method called stellar parallax, or trigonometric parallax. Simply put, they measure a star’s apparent movement against the background of more distant stars as Earth revolves around the sun.

How do astronomers find the distance size luminosity and mass of galaxies?

For more-distant galaxies, astronomers rely on the exploding stars known as supernovae. Like Cepheids, the rate at which a certain class of supernovae brighten and fade reveals their true brightness, which then can be used to calculate their distance.

How can astronomers measure the mass that the galaxy contains inside the orbit of the sun?

How can astronomers measure the mass that the galaxy contains inside the orbit of the Sun? They measure the distance to the center of the Galaxy and the period of the Sun’s orbit and then use a modified version of Kepler’s Third Law.

Why is the use of Hubble’s law to measure distances to galaxies so important to astronomers group of answer choices?

Hubble’s law, which says simply that a galaxy’s velocity (or as is sometimes plotted, its redshift) is directly proportional to its distance, also tells us something important about the state of the universe. If the universe is static and unchanging, there should be no correlation between distance and velocity.

How do astronomers determine gravitational force?

Issac Newton’s Law of Universal Gravitation tells us that the force of attraction between two objects is proportional the product of their masses divided by the square of the distance between their centers of mass. To obtain a reasonable approximation, we assume their geographical centers are their centers of mass.