As we read in the book, a star that appears to be 1 magnitude brighter will have approximately 2.5 times as much flux hitting an observer's detector/telescope/eye (i.e. a star with an apparent magnitude of 4 has approximately 2.5 times more flux hitting the detector as a star with an apparent magnitude of 5). With this in mind what is the approximate ratio of the flux hitting the a detector for a star with an apparent magnitude of 3 compared to a star with an apparent magnitude of 7? (hint: remember that magnitudes follow a logarithmic scale, not a linear one)

You are trying to take an image of a particular star with apparent magnitude m=10, and need to figure out how long you will need to expose for with your telescope. Your friend tells you that her telescope of diameter 0.07 meters can detect the star in 79 minutes. How long would it take for you to use your telescope (diameter 0.13 meters) to detect a star with an apparent magnitude m=12? (Answer in minutes)

If a T Tauri star is the same temperature as the Sun but is eighteen times more luminous, what is its radius relative to the Sun? (Hint: Use the luminosity-radius-temperature relation: L L  =    R R   2     T T   4   .) R R  =

Calculate by how many times Betelgeuse is brighter than the Sun, if its parallax is 0.006 arcsec, and its apparent magnitude is m = +.5. Can you first use the parallax to calculate the distance and then use the magnitude-distance formula to find the absolute magnitude of Betelgeuse and finally, compare it to the absolute magnitude of the Sun which is -26,74 because other experts used other methods and the answer was not correct.

For a star with surface temperature 5,100 K, what is the peak frequency of light from the sun? Write your answer in THz (1012 Hz), to zero decimal places. Take the speed of light to be c=3 x 108 m/s.

We will take a moment to compare how brightly a white dwarf star shines compared to a red giant star. For the sake of this problem, lets assume a white dwarf has a temperature roughly twice as large as a red giant star. As for their stellar radii, the white dwarf has a radius about 1/10000th that of a red giant star. With this in mind, how does the luminosity of a red giant star compare to that of a white dwarf? (Put differently, find the ratio of their luminosities a.k.a. how many times more luminous is the red giant than the white dwarf? An answer of less than 1 means the white dwarf is more luminous, an answer of 1 means they have the same luminosity, and an answer greater than 1 means the red giant is more lu

Which of the following is a true statement? A smaller diameter star can never have a smaller number for its apparent magnitude than a larger star. Two stars with the same diameter and effective surface temperature will necessarily have the same absolute magnitude as well. Aristotle was the first person to detect stellar parallax. All G2 stars necessarily have the same absolute magnitude.

Let us imagine that the spectrum of a star is collected and we find the absorption line of Hydrogen-Alpha (the deepest absorption line of hydrogen in the visible part of the electromagnetic spectrum) to be observed at 656.5 nm instead of 656.3 nm as measured in a lab here on Earth. What is the velocity of this star in m/s? (Hint: speed of light is 3*10^8 m/s; leave the units off of your answer) Question 4 of 7 A Moving to another question will save this response. 1 6:59 & backs

(a) The figure shows the three stars and their velocities. Which star has the largest proper motion? Which star has the smallest proper motion? A B Earth

Suppose a star has a luminosity of 7.0x1026 watts and an apparent brightness of 4.0x10-12 watt/m?. How far away is it? Give your answer in both kilometers and light-years.