Basic Astronomical Data for the Sun (BADS) Eric Mamajek last updated 30 December 2012 (list of updates at bottom of file) _________________________________________________________________ This is a list of fundamental values adopted for the Sun. I am not a solar astronomer, but I occasionally need a solar value time and again for my calculations. If you do not like the values that I have adopted, feel free to email me and justify why I should adopt a different value. If you note the timing of the updates at the bottom of the page, I have been maintaining this file for 5 years now (since May 2007)! #################################################################### # Apparent V Magnitude: V = -26.74 (+-0.02) mag # Absolute V Magnitude: M_V = 4.83 (+-0.02) mag # Absolute B Magnitude: M_B = 5.485 (+-0.02) mag # Bolometric Correction: BCv = -0.08 (+-0.02) mag # Absolute Bolometric Magnitude: Mbol = 4.7554 (+-0.0004) mag # Photospheric Radius: R = 695660 (+-100) km # Photospheric Angular Radius: theta = 959".176 # Solar Oblateness: f = (a-b)/a = 8 X 10^-6 # Spectral Type: SpT = G2 V # Effective Temperature: Teff = 5771.8 +- 0.7 K # Effective Temperature: log10(Teff/K) = 3.76131(+-0.00005) dex # Solar Gravitational Constant (TDB) = 1.32712440041e20 m^3 s^-2 # Solar Gravitational Constant (SI,TCB) = 1.32712442099e20 m^3 s^-2 # Solar Mass: M = 1.98855(24) e30 kg # Solar Bulk Density: rho = 1.4111(2) g cm^-3 # Moment of Inertia: I = 5.96e47 kg m^2 = 5.96e53 g cm^2 # Inertia Constant: k = 0.062 = I/MR^2 # Solar Surface Gravity: g = 27423.2 (+-7.9) cm/s^2 (ignoring rotation, oblateness) # Solar Surface Gravity: g = 274.232 (+-0.079) m/s^2 (ignoring rotation, oblateness) # Solar Surface Gravity: log(g) = 4.43812 (+-0.00013) dex [cgs] (ignoring rotation, oblateness) # Astronomical Unit: AU = 149597870700 m (exact) # Mean Earth-Sun Distance: = 149618753000 m # Total Solar Irradiance: S(@1AU) = 1360.8 (+-0.5) W/m^2 # Luminosity: L_bol = 3.8270 (+-0.0014) e33 erg/s # Mt. Wilson S-value: = 0.1762 # Chromospheric Activity: = -4.903 dex # X-ray Luminosity (0.1-2.4 keV) L_X = 2.24e27 erg/s = 10^27.35 erg/s # X-ray Surface Flux (0.1-2.4 keV) f_X = 36800 erg/s/cm^2 # X-ray/Bol. Ratio log(L_X/L_bol) = -6.24 # Age(Solar System) t = 4572 +- 4 Myr # Protosolar Hydrogen Mass Fraction: Xo = 0.7028-0.7154 # Protosolar Helium Mass Fraction: Yo = 0.2703-0.2783 # Protosolar Metal Mass Fraction: Zo = 0.0142-0.0189 # Photospheric Metal Mass Fraction: Zs = 0.0134-0.0172 # Equatorial Rotation Period: P_eq = 24.47 days # Equatorial Rotation Velocity: V_eq = 2.067 km/s # Mean Rotation Period: