PX282 - A1 - a star

a body bound by self-gravity

radiates energy from an internal source

massive enough for nuclear fusion of hydrogen atoms
this is a working definition, details are complex

the baseline of the knowledge of stars comes from the sun

• spherical(ish), ie: self-bound
• the effective temperature, $T_{eff}\approx 5780K$
• the radius, $R_{\odot }\approx 4\times {10}^{8}m\approx 110R_{\oplus }$
• the mass, $M_{\odot }=2\times {10}^{30}kg\approx 1.7\times {10}^6{M}_{\oplus }$
• age $\approx 4.6Gyr$ (from the age of the oldest moon rocks)
• rotation period $\approx 27days$