1. Stefan boltzmann is sqrt (solar lumo) times (1/solar temp)^2 =solar radius(1). (1/2)^2 is 1/4 or 4= sqrt lumo. Square both sides it's 16 solar lumos. 2. YupPM2017 wrote:Name wrote:1. A star with the same radius and twice the temperature of our sun is found. What is its luminosity (in solar luminosity)?

2. The parallax of a type 1a supernova was found to be .05 milliarcsec. What its distance (in parsecs)?

3. What is the supernovas apparent magnitude?

4. The apparent magnitude of the star in part 1 and the supernova in part 2/3 is the same. What is the distance of the star?Sorry, I was being lazy and did all this on a computer and no paper or pencil, and I just felt lazy, so lazy in fact that I decided to make this sentence a run on sentence.1. 8 (stefan boltzmann) 2. 20,000 (1000/parallax) 3. -2.8 (distance modulus; abs mag is -19.3) 4. really close, or 0.859 parsecs (Abs mag = 2.53, because the 2.5th root of 8 is ~2.30 4.83 - that is 2.53; apparent magnitude is -2.83)

3. Yup

4. Absolute mag is 1.82, knowing the apparent mag is -2.79 so distance is 1.19 parsecs