AST-00 · laboratory
Hubble, Jeans, Eddington, Bondi accretion and the Stefan–Boltzmann star.
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30 governing sheets
Ṁ = 4π λ ρ (G M)² / c_s³. Spherical accretion onto a point mass.
GravityM_J = (π/6) c_s³ / √(G³ ρ). The mass that just collapses against pressure.
GravityL = 4π R² σ T⁴. Blackbody luminosity of a star.
Radiationλ_max T = 2.897×10⁻³ m·K. Peak of B_λ for a blackbody.
Radiationm₁ − m₂ = −2.5 log₁₀ (F₁/F₂). Pogson's scale.
Radiationr_s = 2 G M / c². Event-horizon scale of a non-spinning black hole.
GravityT² = 4π² a³ / (G M). Period of a circular (or mean) orbit.
Gravityv = √(G M / r). Centripetal balance of gravity.
Gravityv_esc = √(2 G M / r). The speed to reach infinity from r.
Gravityν_c = (3/2) γ² ν_L, ν_L = e B / (2π m). Peak of the synchrotron spectrum.
RadiationM_Ch ≈ 1.456 (2/μ_e)² M_⊙. White-dwarf mass limit.
Starsd_L = (c / H₀) z (1 + z/2) in a matter-empty nearby expansion. Pedagogical.
Radiationd(pc) = 1 / p("). The definition of the parsec.
StarsM = 5 R σ² / G for a uniform self-gravitating sphere (η ≈ 5).
Gravityn_{i+1} n_e / n_i = (kT / λ_th³) exp(−χ / kT) (g-factor = 1 sketch).
StarsB_ν = 2 h ν³ / c² / (e^{hν/kT} − 1). Specific intensity of a blackbody.
Radiationr_L / a ≈ 0.49 q^{2/3} / (0.6 q^{2/3} + ln(1+q^{1/3})). Eggleton fit, q = m/M.
Gravityr_H = a (m / 3 M)^{1/3}. The satellite's gravitational territory.
Gravityt_ff = √(3π / 32 G ρ). Collapse time of a uniform sphere.
GravityL/L_⊙ ≈ (M/M_⊙)^{3.5} on the upper main sequence. A power-law sketch.
Starsz = Δλ/λ, v ≈ c z at z ≪ 1. Recession of a nearby galaxy.
Radiationa_tid = 2 G M R / d³. Differential gravity across a body of radius R.
GravitydP/dr = − G M ρ / r². Pressure gradient that holds a star up.
Starsg = G M / R². Surface acceleration of a spherical body.
GravityLocal expansion.
AstroThomson electron scattering.
AstroBlackbody star.
Astro2.95 km per solar mass.
AstroSun: 618 km/s.
AstroParsec definition.
Astro