Sirius The brightest star in the night sky is Sirius, which is at a distance of...
(a) The observed parallax of Sirius, the brightest star in the sky, is 0.375 arcseconds. How far away is it in parsecs? In light years? (b) The Hipparcos spacecraft could measure parallaxes as small as 0.001 a How distant is the furthest star for which we can measure parallax? How does this distance compare to the size of the galaxy!
Sirius, the brightest star in the sky, is a main-sequence star, as is the Sun, but Sirius has a luminosity about 27 times that of the Sun and a mass about 3 times that of the Sun. Use this information to determine which star will live longer, and by what factor, approximately.
The Sun is about 10.0 billion times brighter than the next brightest star, Sirius (as seen from Earth). How far would we have to be from the Sun for the Sun to be as bright as Sirius? We would have to be ___× 10 5th AU or _____light-years away from the Sun.
Hot stars are easily visible in the night sky, but cool stars, which are much more common are much fainter. For example, the star nearest the Sun has a surface temperature of only 300 K and we cannot see it without a telescope. At what wavelength of light is this nearest star the brightest?
The distance from Earth of the red supergiant Betelgeuse is approximately 643 light-years. If it were to explode as a supernova, it would be one of the brightest stars in the sky. Right now, the brightest star other than the Sun is Sirius, with a luminosity of 26LSun and a distance of 8.6 light-years. How much brighter in our sky than Sirius would the Betelgeuse supernova be if it reached a maximum luminosity of 1.1×1010 LSun? Express your answer using...
Consider a bright star in our night sky. Assume its distance from Earth is 31.7 light-years (ly) and its power output is 4.00 x 1028 W, about 100 times that of the Sun. (a) Find the intensity of the starlight at the Earth. 3.54e-8 Your response differs significantly from the correct answer. Rework your solution from the beginning and check each step carefully. nW/m² (b) Find the power of the starlight the Earth intercepts. One light-year is the distance traveled...
Consider a bright star in our night sky. Assume its distance from Earth is 89.1 light-years (ly) and its power output is 4.00 ✕ 1028 W, about 100 times that of the Sun. One light-year is the distance traveled by light through a vacuum in one year. (a) Find the intensity of the starlight at the Earth. Your response differs significantly from the correct answer. Rework your solution from the beginning and check each step carefully. W/m2 (b) Find the...
In the sky, you see a red star and a blue star. Which one is hotter? A. The red star B. They are probably the same temperature C. The blue star D. The answer will depend on how far away the stars are
Q-21.14 Homework Unanswered Due in 5 hours The distance to a star is approximately 8.30 X 10418 m. If this star were to burn out today, in how many years would we see it disappear? Numeric Answer:
Exercise 32.1 - Enhanced - with Feedback Part A How much time does it take light to travel from the moon to the earth, a distance of 384,000 km? Express your answer in seconds. VOARD ? = Submit Request Answer Part B Light from the star Sirius takes 8.61 years to reach the earth. What is the distance to Sirius in kilometers? Express your answer in kilometers. ΑΣφ ? > LE Submit Request Answer