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 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...
choose correct answer. no explanation needed 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...
The brightest star in the northern celestial hemisphere has a surface temperature of about 4300 K and it is 170 times more luminous than the Sun. Calculate the radius of the star in units of the radius of the solar radius (round the result to the nearest integer) In the calculation, you may assume that the Sun has a radius of 7E8 meters and a luminosity of 3.8E26 watts.
Question 16 (1 point) Visible light has wavelengths ranging between approximately 4000 and 7000 Angstroms (400 to 700 nanometres). Which of the following statements is true regarding the surface temperature of a star for which the wavelength of maximum intensity falls in the visible range t could never be cooler than 8000 K It must always be cooler than 5500 K t must lie between 8000 K and 5500 K It must always be hotter than 3500 K Question 17...
2. Which one of the following statements about measuring the mass of an isolated star (a star that is not in a binary star system) is correct? a) the mass of the star can be measured accurately only if its luminosity and temperature can be measured b) the mass of the star cannot be measured accurately c) the mass of the star can be measured accurately only if its distance can be found d) the mass of the star can...