{"id":28,"date":"2016-11-15T21:39:22","date_gmt":"2016-11-15T21:39:22","guid":{"rendered":"https:\/\/courses.lumenlearning.com\/astronomy\/?post_type=chapter&p=28"},"modified":"2016-11-15T21:39:22","modified_gmt":"2016-11-15T21:39:22","slug":"some-useful-constants-for-astronomy","status":"publish","type":"chapter","link":"https:\/\/courses.lumenlearning.com\/towson-astronomy\/chapter\/some-useful-constants-for-astronomy\/","title":{"raw":"Some Useful Constants for Astronomy","rendered":"Some Useful Constants for Astronomy"},"content":{"raw":"\n
Some Useful Constants for Astronomy<\/div>\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n
Physical Constants<\/th>\n<\/tr>\n
Name<\/th>\nValue<\/th>\n<\/tr>\n<\/thead>\n
speed of light (c<\/em>)<\/td>\n2.9979 \u00d7 108<\/sup> m\/s<\/td>\n<\/tr>\n
gravitational constant (G<\/em>)<\/td>\n6.674 \u00d7 10\u221211<\/sup> m3<\/sup>\/(kg s2<\/sup>)<\/td>\n<\/tr>\n
Planck\u2019s constant (h<\/em>)<\/td>\n6.626 \u00d7 10\u221234<\/sup> J-s<\/td>\n<\/tr>\n
mass of a hydrogen atom (M<\/em>H<\/sub>)<\/td>\n1.673 \u00d7 10\u221227<\/sup> kg<\/td>\n<\/tr>\n
mass of an electron (M<\/em>e<\/sub>)<\/td>\n9.109 \u00d7 10\u221231<\/sup> kg<\/td>\n<\/tr>\n
Rydberg constant ( [latex]{R}_{\\infty }[\/latex] )<\/td>\n1.0974 \u00d7 107<\/sup> m\u22121<\/sup>\n<\/td>\n<\/tr>\n
Stefan-Boltzmann constant (\u03c3)<\/td>\n5.670 \u00d7 10\u22128<\/sup> J\/(s\u00b7m2<\/sup> deg4<\/sup>)1<\/sup><\/a>\n<\/td>\n<\/tr>\n
Wien\u2019s law constant (\u03bbmax<\/sub>T)<\/td>\n2.898 \u00d7 10\u22123<\/sup> m K<\/td>\n<\/tr>\n
electron volt (energy) (eV)<\/td>\n1.602 \u00d7 10\u221219<\/sup> J<\/td>\n<\/tr>\n
energy equivalent of 1 ton TNT<\/td>\n4.2 \u00d7 109<\/sup> J<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n
Astronomical Constants<\/th>\n<\/tr>\n
Name<\/th>\nValue<\/th>\n\n<\/tr>\n<\/thead>\n
astronomical unit (AU)<\/td>\n1.496 \u00d7 1011<\/sup> m<\/td>\n<\/tr>\n
Light-year (ly)<\/td>\n9.461 \u00d7 1015<\/sup> m<\/td>\n<\/tr>\n
parsec (pc)<\/td>\n3.086 \u00d7 1016<\/sup> m = 3.262 light-years<\/td>\n<\/tr>\n
sidereal year (y)<\/td>\n3.156 \u00d7 107<\/sup> s<\/td>\n<\/tr>\n
mass of Earth (M<\/em>Earth<\/sub>)<\/td>\n5.974 \u00d7 1024<\/sup> kg<\/td>\n<\/tr>\n
equatorial radius of Earth (R<\/em>Earth<\/sub>)<\/td>\n6.378 \u00d7 106<\/sup> m<\/td>\n<\/tr>\n
obliquity of ecliptic<\/td>\n23.4\u00b0 26\u2019<\/td>\n<\/tr>\n
surface gravity of Earth (g<\/em>)<\/td>\n9.807 m\/s2<\/sup>\n<\/td>\n<\/tr>\n
escape velocity of Earth (v<\/em>Earth<\/sub>)<\/td>\n1.119 \u00d7 104<\/sup> m\/s<\/td>\n<\/tr>\n
mass of Sun (M<\/em>Sun<\/sub>)<\/td>\n1.989 \u00d7 1030<\/sup> kg<\/td>\n<\/tr>\n
equatorial radius of Sun (R<\/em>Sun<\/sub>)<\/td>\n6.960 \u00d7 108<\/sup> m<\/td>\n<\/tr>\n
luminosity of Sun (L<\/em>Sun<\/sub>)<\/td>\n3.85 \u00d7 1026<\/sup> W<\/td>\n<\/tr>\n
solar constant (flux of energy received at Earth) (S)<\/td>\n1.368 \u00d7 103<\/sup> W\/m2<\/sup>\n<\/td>\n<\/tr>\n
Hubble constant (H0<\/sub>)<\/td>\napproximately 20 km\/s per million light-years, or approximately 70 km\/s per megaparsec<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n
\n

Footnotes<\/h2>\n
  1. \n1<\/a> deg stands for degrees Celsius or kelvins<\/li><\/ol>\n<\/div>\n<\/body>","rendered":"
    Some Useful Constants for Astronomy<\/div>\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n
    Physical Constants<\/th>\n<\/tr>\n
    Name<\/th>\nValue<\/th>\n<\/tr>\n<\/thead>\n
    speed of light (c<\/em>)<\/td>\n2.9979 \u00d7 108<\/sup> m\/s<\/td>\n<\/tr>\n
    gravitational constant (G<\/em>)<\/td>\n6.674 \u00d7 10\u221211<\/sup> m3<\/sup>\/(kg s2<\/sup>)<\/td>\n<\/tr>\n
    Planck\u2019s constant (h<\/em>)<\/td>\n6.626 \u00d7 10\u221234<\/sup> J-s<\/td>\n<\/tr>\n
    mass of a hydrogen atom (M<\/em>H<\/sub>)<\/td>\n1.673 \u00d7 10\u221227<\/sup> kg<\/td>\n<\/tr>\n
    mass of an electron (M<\/em>e<\/sub>)<\/td>\n9.109 \u00d7 10\u221231<\/sup> kg<\/td>\n<\/tr>\n
    Rydberg constant ( [latex]{R}_{\\infty }[\/latex] )<\/td>\n1.0974 \u00d7 107<\/sup> m\u22121<\/sup>\n<\/td>\n<\/tr>\n
    Stefan-Boltzmann constant (\u03c3)<\/td>\n5.670 \u00d7 10\u22128<\/sup> J\/(s\u00b7m2<\/sup> deg4<\/sup>)1<\/sup><\/a>\n<\/td>\n<\/tr>\n
    Wien\u2019s law constant (\u03bbmax<\/sub>T)<\/td>\n2.898 \u00d7 10\u22123<\/sup> m K<\/td>\n<\/tr>\n
    electron volt (energy) (eV)<\/td>\n1.602 \u00d7 10\u221219<\/sup> J<\/td>\n<\/tr>\n
    energy equivalent of 1 ton TNT<\/td>\n4.2 \u00d7 109<\/sup> J<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n
    Astronomical Constants<\/th>\n<\/tr>\n
    Name<\/th>\nValue<\/th>\n<\/tr>\n<\/thead>\n
    astronomical unit (AU)<\/td>\n1.496 \u00d7 1011<\/sup> m<\/td>\n<\/tr>\n
    Light-year (ly)<\/td>\n9.461 \u00d7 1015<\/sup> m<\/td>\n<\/tr>\n
    parsec (pc)<\/td>\n3.086 \u00d7 1016<\/sup> m = 3.262 light-years<\/td>\n<\/tr>\n
    sidereal year (y)<\/td>\n3.156 \u00d7 107<\/sup> s<\/td>\n<\/tr>\n
    mass of Earth (M<\/em>Earth<\/sub>)<\/td>\n5.974 \u00d7 1024<\/sup> kg<\/td>\n<\/tr>\n
    equatorial radius of Earth (R<\/em>Earth<\/sub>)<\/td>\n6.378 \u00d7 106<\/sup> m<\/td>\n<\/tr>\n
    obliquity of ecliptic<\/td>\n23.4\u00b0 26\u2019<\/td>\n<\/tr>\n
    surface gravity of Earth (g<\/em>)<\/td>\n9.807 m\/s2<\/sup>\n<\/td>\n<\/tr>\n
    escape velocity of Earth (v<\/em>Earth<\/sub>)<\/td>\n1.119 \u00d7 104<\/sup> m\/s<\/td>\n<\/tr>\n
    mass of Sun (M<\/em>Sun<\/sub>)<\/td>\n1.989 \u00d7 1030<\/sup> kg<\/td>\n<\/tr>\n
    equatorial radius of Sun (R<\/em>Sun<\/sub>)<\/td>\n6.960 \u00d7 108<\/sup> m<\/td>\n<\/tr>\n
    luminosity of Sun (L<\/em>Sun<\/sub>)<\/td>\n3.85 \u00d7 1026<\/sup> W<\/td>\n<\/tr>\n
    solar constant (flux of energy received at Earth) (S)<\/td>\n1.368 \u00d7 103<\/sup> W\/m2<\/sup>\n<\/td>\n<\/tr>\n
    Hubble constant (H0<\/sub>)<\/td>\napproximately 20 km\/s per million light-years, or approximately 70 km\/s per megaparsec<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n
    \n

    Footnotes<\/h2>\n
      \n
    1. \n1<\/a> deg stands for degrees Celsius or kelvins<\/li>\n<\/ol>\n<\/div>\n\n\t\t\t
      \n\t\t\t

      Candela Citations<\/h3>\n\t\t\t\t\t
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