An Etymological Dictionary of Astronomy and Astrophysics
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Having or representing the Sun as a center. → heliocentric cosmology, → heliocentric gravitational constant, → heliocentric Julian Day, → heliocentric parallax, → heliocentric system.

→ helio- + → center + → -ic.

A model of the Universe in which the Sun was centrally located.

→ heliocentric; → cosmology.

A parameter representing the product of the → gravitational constant by the → solar mass. It is 13.27 x 10¹⁹ m³ s^-2.

→ heliocentric; → gravitational; → constant.

The → Julian Date referenced to the center of the → Sun. Since the Earth revolves around the Sun, and since light travels at a finite speed, observations of a given object taken at different positions in the Earth's orbit are not equivalent, and so a correction for Earth's orbit around the Sun is required. Left uncorrected, the time of an observational event measured by Earth clocks will vary by 16.6 minute over the course of a year. If not properly accounted for, this can lead to a spurious signal in a → periodogram.

→ heliocentric; → Julian Date.

The parallax of a celestial body when viewed from two points in the Earth's orbit around the Sun. More specifically, the angular difference in a celestial object's position as seen from the center of the Sun and the center of the Earth. Also called → annual parallax.

→ heliocentric; → parallax.

A system in which the Sun is assumed to lie at its central point while the Earth and other bodies revolve around it.

→ heliocentric; → system.