Exercise - 15. 3. 2011

Exercise 1 - Parameters of stars:

  • Distance and the spectral class of stars: Find 4 nearest stars and find out their spectral class, use Solar Neighborhood simulation.
  • Luminosity of stars: Find luminosity of the star that is twice as hot as the Sun and has 5 times bigger diameter, use simulation Stellar Luminosity
  • Luminosity of stars: Find ratio (diameter of Deneb)/(diameter of the Sun) and (temperature of Deneb)/(temperature of the Sun) and calculate (luminosity of Deneb)/(luminosity of the Sun). Use alpha.wolfram.com.
  • Colour of stars: find temperature of star that emits maximum of lights on the red colour, use simulation Blackbody Spectrum
  • Colour of stars: find the temperature and the color of stars Sun, Betelgeuse and Rigel. Use alpha.wolfram.com (hint: try "color Sun").
  • Stelar radius: Comparise radius of star of the of main Sequence with spectral class O and M with the Sun (spectral class of Sun is G2). Use Radius and Temperature of Main Sequence Stars
  • Nucleosynthesis: find between which two nucleus is the biggest difference in the binding energy in CNO cycle, use Stellar Nucleosynthesis
  • Quiz - stellar evolution: Try to answer the question on interactive quiz 1. interactive quiz 2.

    Exercise - 8. 3. 2011

    Exercise 1

    Statistics of the Stars:
  • Find 20 of the most brightest stars
  • Find 20 of the stars with greatest absolute magnitude
  • Find 20 of nearest stars
  • Find 20 of the most distant stars
  • Find the most possible northern star
  • Find 20 of the stars with the greatest parallax
  • How many stars are of the negative (between 0 and 1, 1 and 2, 2 and 3) apparent magnitude?

    Solution

    Special exercise to the home: estimate the total apparent magnitude of the all of naked eye visible stars (to the mag. of 6 except for Sun).
    Note: this small catalogue contain stars to the distance of 20 l.y. and all of stars that are of the magnitude to 6.5 with distance limit of 50 l.y. and all of the stars on the sky of the apparent magnitude to 4.0.

    Star database (each open each own database): Stars_1 Stars_2 Stars_3 Stars_4 Stars_5


    Exercise 2

    Look at the interresting astronomical objects on the Astronomy Picture of the Day

  • Nebulae (dark, emission, reflexion, planetary, supernnova remnants)
  • Galaxies
  • Clusters of stars
  • Comets
  • ...

    See video Star size comparison at APOD and note, which is the most known giant star and how big it is.
    See picture of Betelgeuse (and other picture here and the oldiest picture from 1996) and answer the question: is that real optical picture? Which only stars are visible direct with optical instruments?
    See picture of colour of stars in Orion constellation and answer the question: how depends colour of stars on their temperature?