Astrophysics (Index)About

J2000.0 equinox

(equinox as of the J2000.0 epoch used as a positional reference)

J2000.0 equinox is a standard direction (equivalently, a specific point on the celestial sphere) currently used as a reference in astronomy being the position of the vernal equinox (March equinox) as of epoch J2000.0 (the equinoxes undergo a slow, constant shift, i.e., the precession of the equinoxes). The direction is taken as coordinates J000000+000000 in the current standard equatorial coordinate system (i.e., with coordinates right ascension and declination). Like the standard epoch, earlier such standard equinoxes were used, generally for reports/catalogs near in time to their respective epochs. For example, prior to standardization of the J2000.0 equinox, the B1950.0 equinox (analogously based on epoch B1950.0) was commonly used. The J2000.0 vernal equinox in the B1950.0 coordinates is approximately B235726.23391-001641.2260. Conversely, the B1950.0 vernal equinox in J2000.0 coordinates is approximately J000233.76588+001642.2244.


(astronomy,designation)
Further reading:
https://en.wikipedia.org/wiki/Equinox_(celestial_coordinates)#J2000.0
https://oneau.wordpress.com/2011/10/27/equinox-epoch/
Coordinates:J2000.0 equinox
J000000+000000

Referenced by pages:
celestial reference frame
epoch B1950.0
epoch J2000.0
equinox
J designator
precession of the equinoxes

Index