Search results
Results from the WOW.Com Content Network
Right ascension (abbreviated RA; symbol α) is the angular distance of a particular point measured eastward along the celestial equator from the Sun at the March equinox to the (hour circle of the) point in question above the Earth. [ 1 ] When paired with declination, these astronomical coordinates specify the location of a point on the ...
Right ascension is usually measured in sidereal hours, minutes and seconds instead of degrees, a result of the method of measuring right ascensions by timing the passage of objects across the meridian as the Earth rotates. There are 360° / 24 h = 15° in one hour of right ascension, and 24 h of right ascension around the entire ...
In the equatorial coordinate system, the right ascension coordinates of these borders lie between 00 h 27 m 03 s and 23 h 41 m 06 s, while the declination coordinates are between 77.69° and 46.68°. [3] Its position in the Northern Celestial Hemisphere means that the whole constellation is visible to observers north of 12°S.
Right ascension and declination as seen on the inside of the celestial sphere. The primary direction of the system is the vernal equinox, the ascending node of the ecliptic (red) on the celestial equator (blue). Declination is measured northward or southward from the celestial equator, along the hour circle passing through the point in question.
The location of an object in space can be defined in terms of right ascension and declination which are measured from the vernal equinox and the celestial equator. Right ascension and declination are spherical coordinates analogous to longitude and latitude , respectively.
Because it is so close to the celestial north pole, its right ascension is changing rapidly due to the precession of Earth's axis, going from 2.5h in AD 2000 to 6h in AD 2100. Twice in each sidereal day Polaris's azimuth is true north; the rest of the time it is displaced eastward or westward, and the bearing must be corrected using tables or a ...
In the equatorial coordinate system, the right ascension coordinates of these borders lie between 03 h 23.4 m and 05 h 53.3 m, while the declination coordinates are between 31.10° and −1.35°. [7] Because a small part of the constellation lies to the south of the celestial equator, this can not be a completely circumpolar constellation at ...
In the equatorial coordinate system, epoch 2000, the right ascension coordinates of these borders lie between 16 h 00 m 26.64 s and 18 h 57 m 49.50 s, while the declination coordinates are between +3.67° and +51.32°. [4] In mid-northern latitudes, Hercules is best observed from mid-spring until early autumn, culminating at midnight on June 13 ...