Which of the following distance measuring techniques works to measure distances to other galaxies beyond the Milky Way? CHECK ALL THAT APPLY
A) Hubble's Law
B) main sequence stars
C) Cepheid variable stars
D) parallax
E) radar ranging
F) galaxy rotation
G) white dwarf supernovae
I believe the answers are B, C, and G. Could someone please tell me if I'm right and explain this to me?
A) will give an approximate value for distant galaxies. Close galaxies can vary a lot from the Hubble relation because of local velocity differences. (Out nearest glaxy is actually getting closer and will eventually collide with the Milky Way!) By the way, Hubble's "Law" is not considered a law. It is an approximately linear relation between velocity and distance, based on a curve fit to scattered data.
C) is a good answer
G) would be OK is it just said "supernovae", but white dwarfs do not become supernovae
The other choices are nonsense.
To determine which distance measuring techniques work to measure distances to other galaxies beyond the Milky Way, let's go through each option and see if they apply:
A) Hubble's Law: This technique does work to measure distances to other galaxies beyond the Milky Way. It is based on the observation that galaxies are moving away from us, and the more distant a galaxy is, the faster it appears to be moving away. By measuring the redshift of the light from distant galaxies, astronomers can calculate their distances using Hubble's Law.
B) Main sequence stars: This technique is not typically used to measure distances to other galaxies beyond the Milky Way. Main sequence stars are not bright enough to be visible at such large distances.
C) Cepheid variable stars: This technique does work to measure distances to other galaxies beyond the Milky Way. Cepheid variables are a type of pulsating stars with a well-known relationship between the period of their brightness variations and their luminosity. By observing the period of a Cepheid variable star, astronomers can determine its intrinsic brightness and use that information to calculate its distance.
D) Parallax: Parallax is a technique used for measuring distances to objects within our own galaxy, but it is not useful for measuring distances to other galaxies beyond the Milky Way.
E) Radar ranging: Radar ranging is a technique used for measuring distances to objects within our own Solar System and is not suitable for measuring distances to other galaxies.
F) Galaxy rotation: This technique is not typically used to directly measure distances to other galaxies. Galaxy rotation curves can provide information about the mass distribution within a galaxy, but distance measurements to other galaxies are usually derived from other methods.
G) White dwarf supernovae: This technique does work to measure distances to other galaxies beyond the Milky Way. White dwarf supernovae, also known as Type Ia supernovae, are incredibly luminous explosions that can be observed even at very large distances. These explosions have a known intrinsic brightness, allowing astronomers to calculate their distances by comparing their observed brightness with their expected brightness.
Based on the explanations provided, the correct answers for measuring distances to other galaxies beyond the Milky Way are A) Hubble's Law, C) Cepheid variable stars, and G) white dwarf supernovae.