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Paul Francis -- Astronomical Constants

Physical and Astronomical Constants

Units

  • 1 Dyn = 10 micronewtons
  • 1 erg = 0.1 microjoules
  • 1 Jansky = 10**-26 watts per metre square per hertz
  • 1 Angstrom = 0.1 nanometres
  • 1 Megaton = 4*10**15 Joules

    Cosmological Equations

    Signal-to-Noise Equations

    Filters and Magnitudes

    An AB magnitude is calculated by the equation
    AB=-2.5 log10(flux) - 48.60
    Where flux is per unit frequency in erg/cm2/2/Hz. From Oke and Gunn 1983.

    Sky Brightnesses

    Astronomical Quantities

  • Wavelength of H-alpha = 6562.8 Angstroms
  • 1 Astronomical unit = 1.4960 times 10**11 m
  • 1 Parsec = 3.0857 times 10**16 m
  • Mass of Sun = 1.989 times 10**30 kg
  • Radius of Sun = 6.96 times 10**8 m
  • Solar Luminosity = 3.8 times 10**26 W
  • Mass of the Earth = 5.976 times 10**24 kg
  • Mass of Jupiter = 318 times mass of Earth
  • Solar constant = 1.37 kW per metre

    Physical Constants

  • c= 3 times 10**8 metres per second
  • Mass of Proton = 1.67 times 10**-27 kg
  • Mass of Proton = 1836.1 times mass of electron
  • h = 6.62 times 10**-34 Js
  • e = 1.602 times 10**-19 C
  • Avogadro's number = 6 times 10**23 per mole
  • G = 6.67 times 10**-11 N m**2 kg**-2
  • k = 1.38 times 10**-23 J K**-1
  • Stefan Boltzmann constant = 5.67 times 10**-8 W m**-2 K**-4
  • Square degrees on a sphere = 41253

    Last Modified: 12th March 2003

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