{"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":"2017-07-26T18:24:50","modified_gmt":"2017-07-26T18:24:50","slug":"some-useful-constants-for-astronomy","status":"publish","type":"chapter","link":"https:\/\/courses.lumenlearning.com\/suny-ncc-astronomy\/chapter\/some-useful-constants-for-astronomy\/","title":{"raw":"Some Useful Constants for Astronomy","rendered":"Some Useful Constants for Astronomy"},"content":{"raw":" \r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n
Physical Constants<\/th>\r\n<\/tr>\r\n
Name<\/th>\r\nValue<\/th>\r\n<\/tr>\r\n<\/thead>\r\n
speed of light (c<\/em>)<\/td>\r\n2.9979 \u00d7 108<\/sup> m\/s<\/td>\r\n<\/tr>\r\n
gravitational constant (G<\/em>)<\/td>\r\n6.674 \u00d7 10\u221211<\/sup> m3<\/sup>\/(kg s2<\/sup>)<\/td>\r\n<\/tr>\r\n
Planck\u2019s constant (h<\/em>)<\/td>\r\n6.626 \u00d7 10\u221234<\/sup> J-s<\/td>\r\n<\/tr>\r\n
mass of a hydrogen atom (M<\/em>H<\/sub>)<\/td>\r\n1.673 \u00d7 10\u221227<\/sup> kg<\/td>\r\n<\/tr>\r\n
mass of an electron (M<\/em>e<\/sub>)<\/td>\r\n9.109 \u00d7 10\u221231<\/sup> kg<\/td>\r\n<\/tr>\r\n
Rydberg constant ( [latex]{R}_{\\infty }[\/latex] )<\/td>\r\n1.0974 \u00d7 107<\/sup> m\u22121<\/sup><\/td>\r\n<\/tr>\r\n
Stefan-Boltzmann constant (\u03c3)<\/td>\r\n5.670 \u00d7 10\u22128<\/sup> J\/(s\u00b7m2<\/sup> deg4<\/sup>)[footnote]<\/sup><\/a>deg stands for degrees Celsius or kelvins [\/footnote]<\/sup><\/a><\/td>\r\n<\/tr>\r\n
Wien\u2019s law constant (\u03bbmax<\/sub>T)<\/td>\r\n2.898 \u00d7 10\u22123<\/sup> m K<\/td>\r\n<\/tr>\r\n
electron volt (energy) (eV)<\/td>\r\n1.602 \u00d7 10\u221219<\/sup> J<\/td>\r\n<\/tr>\r\n
energy equivalent of 1 ton TNT<\/td>\r\n4.2 \u00d7 109<\/sup> J<\/td>\r\n<\/tr>\r\n<\/tbody>\r\n<\/table>\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n
Astronomical Constants<\/strong><\/td>\r\n<\/tr>\r\n
Name<\/strong><\/td>\r\nValue<\/strong><\/td>\r\n<\/tr>\r\n
astronomical unit (AU)<\/td>\r\n1.496 \u00d7 1011<\/sup> m<\/td>\r\n<\/tr>\r\n
Light-year (ly)<\/td>\r\n9.461 \u00d7 1015<\/sup> m<\/td>\r\n<\/tr>\r\n
parsec (pc)<\/td>\r\n3.086 \u00d7 1016<\/sup> m = 3.262 light-years<\/td>\r\n<\/tr>\r\n
sidereal year (y)<\/td>\r\n3.156 \u00d7 107<\/sup> s<\/td>\r\n<\/tr>\r\n
mass of Earth\u00a0(R<\/em>Earth<\/sub>)<\/td>\r\n5.974 \u00d7 1024<\/sup> kg<\/td>\r\n<\/tr>\r\n
equatorial radius of Earth<\/td>\r\n6.378 \u00d7 106<\/sup> m<\/td>\r\n<\/tr>\r\n
obliquity of ecliptic<\/td>\r\n23.4\u00b0 26\u2019<\/td>\r\n<\/tr>\r\n
escape velocity of Earth\u00a0(v<\/em>Earth<\/sub>)<\/td>\r\n1.119 \u00d7 104<\/sup> m\/s<\/td>\r\n<\/tr>\r\n
mass of Sun\u00a0(M<\/em>Sun<\/sub>)<\/td>\r\n1.989 \u00d7 1030<\/sup> kg<\/td>\r\n<\/tr>\r\n
equatorial radius of Sun\u00a0(R<\/em>Sun<\/sub>)<\/td>\r\n6.960 \u00d7 108<\/sup> m<\/td>\r\n<\/tr>\r\n
luminosity of Sun\u00a0(L<\/em>Sun<\/sub>)<\/td>\r\n3.85 \u00d7 1026<\/sup> W<\/td>\r\n<\/tr>\r\n
solar constant (flux of energy received at Earth) (S)<\/td>\r\n1.368 \u00d7 103<\/sup> W\/m2<\/sup><\/td>\r\n<\/tr>\r\n
Hubble constant\u00a0(H0<\/sub>)<\/td>\r\n\u00a0approximately 20 km\/s per million light-years, or approximately 70 km\/s per megaparsec<\/td>\r\n<\/td>\r\n<\/td>\r\n<\/tr>\r\n<\/tbody>\r\n<\/table>\r\n

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 <\/p>\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><\/td>\n<\/tr>\n
Stefan-Boltzmann constant (\u03c3)<\/td>\n5.670 \u00d7 10\u22128<\/sup> J\/(s\u00b7m2<\/sup> deg4<\/sup>)[1]<\/sup><\/a><\/sup><\/a><\/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
Astronomical Constants<\/strong><\/td>\n<\/tr>\n
Name<\/strong><\/td>\nValue<\/strong><\/td>\n<\/tr>\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\u00a0(R<\/em>Earth<\/sub>)<\/td>\n5.974 \u00d7 1024<\/sup> kg<\/td>\n<\/tr>\n
equatorial radius of Earth<\/td>\n6.378 \u00d7 106<\/sup> m<\/td>\n<\/tr>\n
obliquity of ecliptic<\/td>\n23.4\u00b0 26\u2019<\/td>\n<\/tr>\n
escape velocity of Earth\u00a0(v<\/em>Earth<\/sub>)<\/td>\n1.119 \u00d7 104<\/sup> m\/s<\/td>\n<\/tr>\n
mass of Sun\u00a0(M<\/em>Sun<\/sub>)<\/td>\n1.989 \u00d7 1030<\/sup> kg<\/td>\n<\/tr>\n
equatorial radius of Sun\u00a0(R<\/em>Sun<\/sub>)<\/td>\n6.960 \u00d7 108<\/sup> m<\/td>\n<\/tr>\n
luminosity of Sun\u00a0(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><\/td>\n<\/tr>\n
Hubble constant\u00a0(H0<\/sub>)<\/td>\n\u00a0approximately 20 km\/s per million light-years, or approximately 70 km\/s per megaparsec<\/td>\n<\/td>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

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