Question
Expert Solution
arrow_forward
Concept and Principle:
- Luminosity can be defined as an absolute measure of radiated power emitted by a light source over time. In astronomy, it gives us the energy emitted per unit of time by a star, galaxy, or any other astronomical object.
- Absolute magnitude is a measure of luminosity. It defines how bright a star would be if it was observed from a distance of 10 pc.
- The relationship between absolute magnitude and luminosity is given by,
Here L is the luminosity of the star and L0 is the zero-point luminosity and has a value of 3.0128 × 1028 W.
Step by stepSolved in 3 steps
Knowledge Booster
Similar questions
- Integrate the first equation over all wavelengths to find an expression for the total luminosity of a black body star. (See the second equation for a hint)arrow_forward3- Consider a binary star system in which the two stars are seen to be 1.50" apart. Determine the actual physical separation of those stars (in AU) if this binary system is located 9.50 1.y. from us.arrow_forwardIf a star has a surface temperature of 25,000 K (2.50 ✕ 104 K), at what wavelength (in nm) will it radiate the most energy? nm Is this a cool or hot star? (Give your answer relative to the Sun.) coolhotarrow_forward
- 31) Star Sirius has an apparent magnitude of -1.47 and an absolute magnitude of 1.41. Estimate the distance to Sirius.arrow_forwardGo to Question 8 60 Msun I luminosity (solar units) 106 105 104 103 102 10 0.1 10-2 10-3 10-4 10-5 30 Msun 10 Solar Radii Lifetime 10 yrs 1 Solar Radius 0.1 Solar Radius 10-2 Solar Radius 10-3 Solar Radius 30,000 increasing temperature 102 Solar Radi B Centauri Spica 10 Msun Bellatrix MAIN Sirius B Lifetime 108 yrs B Rigel Deneb 6 Msun Achernar SEQUENCE Lifetime 10⁹ yrs WHITE SUPERGIANTS Msun Vega DWARFS Procyon B 103 Solar Radi Sirius Lifetime 1010 yrs A 10,000 Altair Canopus Procyon Sun Arcturus Polaris Lifetime 10¹1 yrs T Ceti 6,000 surface temperature (Kelvin) GIANTS x Centauri A Pollux x Centauri B Eridani F G K Aldebaran Barnard's Star Betelgeuse 61 Cygni A 61 Cygni B Lacaille 9352 0.3 Msun Antares M (It may help you to know that 1 Lsun is 3.8 x 1026 Watts. Use 3.1415 for Pi.) Wolf 359 Proxima Centauri DX Cancri Gliese 725 A Gliese 725 B 0.1 Msun Ross 128 3,000 decreasing temperature The physics of thermally radiating gases relates the luminosity (L), temperature (T) and radius…arrow_forwardAt rest hydrogen has a spectral line at 149nm. If this line is observed at 144 nm for the star proxima how fast is proxima moving in km/sarrow_forward
- 33) A star is observed to be having an absolute magnitude of -5.6 and is located at a distance of 159.96 pc. Estimate the apparent magnitudearrow_forward8) A neutron star is found with a radius of 10 km and has a surface temperature of 1,000,000 K. Calculate its luminosity with respect to that of the Sun. nts)arrow_forward6) Estimate the distance to the star with absolute magnitude -5.6 and apparent magnitude 0.75arrow_forward
arrow_back_ios
arrow_forward_ios