The International Celestial Reference System (ICRS) is the current standard celestial reference system adopted by the International Astronomical Union (IAU). Its origin is at the barycenter of the solar system, with axes that are intended to be "fixed" with respect to space. ICRS coordinates are approximately the same as equatorial coordinates: the mean pole at J2000.0 in the ICRS lies at 17.3±0.2 mas in the direction 12 h and 5.1±0.2 mas in the direction 18 h. The mean equinox of J2000.0 is shifted from the ICRS right ascension origin by 78±10 mas (direct rotation around the polar axis).
Famous quotes containing the words celestial, reference and/or system:
“Such is always the pursuit of knowledge. The celestial fruits, the golden apples of the Hesperides, are ever guarded by a hundred-headed dragon which never sleeps, so that it is an Herculean labor to pluck them.”
—Henry David Thoreau (1817–1862)
“The common behavior of mankind is the system of reference by means of which we interpret an unknown language.”
—Ludwig Wittgenstein (1889–1951)
“Daily life is governed by an economic system in which the production and consumption of insults tends to balance out.”
—Raoul Vaneigem (b. 1934)