When measuring the distance between the star and the earth, the triangle parallax method is popular at present. The triangle parallax method puts the measured celestial body on the vertex of a super-large triangle, and the earth and the sun are the other two vertices of the triangle. The connection between celestial bodies and the earth and the sun will form an included angle. By measuring the visual angle from the earth to the celestial body, we can find out the distance between the celestial body and the earth. The unit of included angle is angular seconds, and the unit of distance is parsec. The number of angular seconds and the number of parsec are reciprocal. 38860 . 68888888686
Other methods include spectral parallax, cluster parallax, statistical parallax, paternal parallax and mechanical parallax.