Two stars, named A and B, each with a mass equal to the Sun's mass are in orbit around each other. If the distance between the two stars is 1.0 AU. What is the period of their orbit?

In 3–5 sentences, explain how the shape of planetary orbits affects their orbital velocity. Include the proper law of planetary motion as part of your answer. In 3–5 sentences, explain how the shape of planetary orbits affects their orbital velocity. Include the proper law of planetary motion as part of your answer.

2. Over several months an astronomer observes an exoplanet orbiting a distant star at a distance of 5.934 AU. Its orbit period was projected to be 3.875 years. Convert the orbit radius to meters and period to seconds. Use this information to calculate the mass M of the star in kg and solar mass units (Mo). Star Exoplanet Orbit radius (m) Orbit period (s) Star mass (kg) Star mass (Mo)

1. What would be the diameter (of the event horizon) of a black hole with the same mass as Jupiter? (2 points) answer: D BH ft m =

If we view a star now, and then view it again 6 months later, our position will have changed by the diameter of the Earth's orbit around the sun. For nearby stars (within 100 light-years or so), the change in viewing location is sufficient to make the star appear to be in a slightly different location in the sky. Half of the angle from one location to the next is known as the parallax angle (see figure). Parallax can be used to measure the distance to the star. An approximate relationship is given by d =  3.26 p , where d is the distance in light-years, and p is the parallax measured in seconds of arc. Vega is a star that has a parallax angle of 0.13 second. How far is Vega from the sun? Note: Parallax is used not only to measure stellar distances. Our binocular vision actually provides the brain with a parallax angle that it uses to estimate distances to objects we see. (Round your answer to two decimal places.)  light-years

(a) The distance to a star is approximately 7.80 1018 m. If this star were to burn out today, in how many years would we see it disappear? years (b) How long does it take for sunlight to reach Saturn?

You measure a star to have a parallax angle of 0.12 arc-seconds What is the distance to this star in parsecs? 8.33 Hint: d = 1/p What is the parallax angle of a different star that is twice as far away as the star from the previous problems? [answer in arc-seconds without including the unit]

15: A star has a parallax angle of 0.0270 arcseconds and an apparent magnitude of 4.641. What is the distance to this star?  Answer: 37 16: What is the absolute magnitude of this star? Answer:1.8 17: Is this star more or less luminous than the Sun? Answer "M" for More luminous or "L" for Less luminous. (HINT: the absolute magnitude of the Sun is 4.8) Answer: M  18: What is the luminosity of this star? (HINT: The luminosity of the Sun is 3.85×1026 W.) Please answer question #18, #15-17 are correct, the photos provide the work for them.

Direction: Use your knowledge about solving equations to work out to complete the table below. Show your solution with proper units. R° (meters) T R° / T° { (meters) / Planet Average Times of Radius of Revolution (seconds) (seconds) } Planet's Orbit (Planet's year) R T (seconds) (meters) Mercury 5.7869 x 10:0 7.605 x 10 Venus 1.081 x 101 1.941 x 107 Earth 1.4996 x 10" 3.156 x 10 Mars 2.280 x 101 5.936 x 10 Jupiter 7.783 x 10" 3.743 x 10 Saturn 1.426 x 10 9.296 x 10

Explain how the brightness of a star can be used to estimate its distance from Earth.