Recent content by JoAstro

Definitely need that refresh! Thank you :)

TSny, thanks for pointing that out. I used google as I don't know a way to go at it. May I ask if you know how to convert these values? :)

Homework Statement I am trying to find the tangential velocity of a star but I am confused with the whole procedure. Homework Equations [/B] They give me the following data: ⋅Distance: 32parsecs ⋅μ: 0.24 arc seconds per year I have a section explaining proper motion that states the...

Indeed my images have a shorter lifespan with only 27 years apart and this number is the one I'm told to use to find the proper motion of the knots. The other online source was using scales 52 years apart. But since my plates are both dated (1973 and 2000) I have to stick to the 27 year...

Hi gnaill, Sorry for the slow answer. First, I am sorry about my poor explanation above. It was very late that night and my frustration levels were (are) very high. To answer your questions about my confusion for this lab work... You are totally right, to calculate the plate scale I take the...

Homework Statement Hi, I am trying to use the angular velocity and angular position to find the age of the Crab Nebula but my calculations seem to be erroneous. I am supposed to get a number around 800 but I keep getting 5000+ years of age. I'm going to try to be very specific in what I'm...

I have two statements and they say as follows: 1. A 3sun star is seen to have a luminosity of 40 Lsun, which is too bright to be from the main sequence. 2. Two stars of the same mass must have the same luminosity. I know that the first one is partly true but according to the solar-luminosity...

As the Stephan-Boltzmann's Law says, the minimal change in a star's mass would have a massive effect on its luminosity, but can necessarily two stars with the same mass have the same luminosity?

Hi Simon, Thank you for your answer. I noticed I somehow managed to plug the value in the wrong way and get an incorrect answer as Vela says above. However, I believe my conversion for micrometer to meters is wrong since the answer I get is -5.971 and that looks very weird to be a temperature...

I am trying to find the temperature of a star given its wavelength in micrometres, but I am not sure if my conversion is right therefore don't know if the answer is correct. Star A has a maximum emission wavelength of 1 μm and Radius 100 Rsun. What is its Effective Temperature and Luminosity...

Hi, bobo1455. I have the same kind of problem only with different values. I was wondering if you found your answer. I am struggling a lot to get an answer since I don't know where to start. -- I was told the flux of the Sun is the key, but I can't see any relation to what I need to do to be...

Having the unaided eye's pupil to be 6.4mm and the diameter of a telescope 8-inches, how can I calculate the amount of light the a scope collects over the human eye?

Hi Andrew. Thank you! I'm not sure about what you say, but I just noticed that I misread the question thinking it was another. The real question was meant for hydrogen which said "What is the typical thermal energy of a hydrogen atom?" However, the question I meant to ask was "What is the...

I have this formula "E= 1/2 mv^2" which I don't fully understand. Also, I don't have the values for helium's mass and velocity.