Question 2. The supergiant star Rigel has a parallax 3.78 mas, apparent magnitude m = 0.1, and surface temperature T = 12,100 K. Calculate its: distance [parsec] luminosity [solar units], radius [solar radii]
Question 2. The supergiant star Rigel has a parallax 3.78 mas, apparent magnitude m = 0.1,...
Question 1. A star has a parallax 0.043 arcsec and an apparent magnitude m = 7.8. Calculate its distance (parsec) and luminosity. Express the luminosity in watts and as a percentage of the solar luminosity.
The bright star Rigel in the constellation Orion has a surface temperature about 1.6 times that of the Sun. Its luminosity is about 64,000 times that of the Sun. What is Rigel's radius compared to the radius of the Sun (in units of solar radii, Rø)?
1. A star has a parallax of 0.324 arcseconds and apparent magnitude in V-band m= +1.55. Later observations reveal that the “star” is actually a close binary, with members star 1 and star 2. Star 1 is found to have mı = +1.83. (a) Find the apparent magnitude of star 2, m2. [2 marks] (b) What is the ratio of the V-band flux received from star 1 to that received from star 2? (c) Find the distance to the system...
The star Sirius has an apparent magnitude ?V = −1.46 and a parallax ? = 0.37921”.(a) Calculate its distance and absolute magnitude. (b) What would Sirius’ parallax be if it were measured from an observatory on Neptune’s moon Triton as Neptune orbited theSun?
Stellar RadiiThe red supergiant (RSG) star Betelgeuse has a luminosity of 120,000L, and a surface temperature ofaboutTeff= 3650 K. What is its’ radius (in both metres and astronomical units)?
6. The bright star Arcturus in the constellation Boötes has a surface temperature about 0.74 times that of the Sun. Its luminosity is about 170 times that of the Sun. (a) What is Arcturus’ radius compared to the radius of the Sun (in units of solar radii, ?⊙)? (b) What type of star is Arcturus (a dwarf, a giant, or a supergiant)? Explain your reasoning.
5. Wien's Law and Stefan-Boltzmann Law A supergiant star has a surface T of 21,000 K. Its power output is 80,000 times that of the Sun; the Sun's power is 3.9 x1026 W. a. What is Amax for this supergiant star? b. What part of the electromagnetic spectrum is this? c. What is the radius of this supergiant, in meters? Treat it as a perfect black bod d. How many solar radii is this? y. An old-school lightbulb is about...
9) How distant is a star whose modulus is -7.5? 10) If its apparent magnitude (m) = +13.5 and absolute magnitude (M) = +10, what is the distance to a star? PROBLEMS TO COMPLETE FOR PARALLAX 11) A star has a parallax of .025 seconds of arc—what is its distance in parsecs? The nearest star has a parallax of 76 arc seconds—what is its distance in light years? 12) If star were 2.40 pc from Earth, what would its distance...
3. [9 marks] You have access to a small professional telescope that is able to record the ultraviolet through infrared spectrum of a star in the constellation of Orion. You determine that the wavelength of light at the peak of the spectrum is 922.93 nm. The star’s apparent magnitude is m = 0.45. a) [2 marks] Determine the star’s surface temperature in units of Kelvin (K). b) [3 marks] Using the solar constant and the Sun’s apparent magnitude, determine the...
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QUESTION 36 What does the apparent magnitude of a star tell us about that star? its mass how bright it appears from Earth its radius how much energy it is emitting QUESTION 37 What is the reason sunspots appear darker than surrounding regions on the Sun's surface? They actually are fairly bright, but appear dark against the even brighter background of the surrounding photosphere. They are too cold to emit any visible light. They...