Right ascension (abbrev. RA; symbol α = Greek letter alpha) is the astronomical term for one of the two coordinates of a point on the celestial sphere when using the equatorial coordinate system.
Right Ascension
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RIGHT ASCENSION, in astronomy, that co-ordinate of a heavenly body defined by the angle which the meridian passing through it makes with the prime meridian through the vertical equinox (see Astronomy).
Right Ascension
Related Category: Astronomy: General
in astronomy, one of the coordinates in the equatorial coordinate system.
Right Ascension
Along with the declination (Dec) and epoch, the 'right ascension' (RA) of an object is used to define its position on the celestial sphere in the equatorial coordinate system.
right ascension
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Right Ascension
The azimuthal angle at which the of a celestial object is located. The rotation axis taken as the direction of the celestial pole.
The right ascension of the north-south line -- the meridian -- drawn directly overhead at any given moment is the local sidereal time.
Definition: Right Ascension: Coordinate for measuring east-west position for an object in the sky.
Right Ascension and Declination for Sirius
This tells us that when the vernal equinox is on our celestial meridian, it will be 6 hours and 45 minutes before Sirius crosses our celestial meridian, ...
right ascension Celestial coordinate used to measure longitude on the celestial sphere. The zero point is the position of the Sun on the vernal equinox.
rille A ditch on the surface of the Moon where molten lava flowed in the past.
right ascension: [α, RA] a co-ordinate used by astronomers, as part of the equatorial co-ordinate system, (together with declination) to define the position of a celestial body.
Right Ascension (R.A.)
R.A. is one of the co-ordinates used to locate positions on the celestial sphere.
right ascension
the angular distance of a celestial object east of the vernal equinox; the celestial sphere equivalent of longitude
rotation ...
Right Ascension and Declination
The globe of the heavens resembles the globe of the Earth, and positions on it are marked in a similar way, ...
Right ascension. One element of the astronomical coordinate system on the sky, which can be though of as longitude on the earth projected onto the sky.
Right ascension (R.A.) Part of the equatorial co-ordinate system used to specify the location of an object in the sky. It is the angular distance of an object from an imaginary line in the sky.
Right ascension: The equatorial coordinate specifying the angle (usually specified in hours, minutes and seconds), measured eastward along the celestial equator from the vernal equinox to the hour circle passing through an object in the sky.
Right ascension- the celestial coordinate analogous to longitude on Earth
Roche Limit- the closest one celestial object can get to another before the weaker object is broken apart by tidal effects ...
Right Ascension (RA) The angle, measured eastward on the celestial equator, between the First Point of Aries and the hour circle through the object.
S
Schmidt, Schmidt-Cassegrain, Schmidt Newtonian Forms of catadioptric telescope.
Right Ascension
Angular distance on the celestial sphere measured eastward along the celestial equator from the equinox to the hour circle passing through the celestial object. Right ascension is usually given in combination with declination.
right ascension
A component of the coordinate system used to designate positions on the celestial sphere.
Right Ascension
A coordinate which, along with declination, may be used to locate any position in the sky. Right ascension is analogous to longitude for locating positions on the Earth.
Right ascension (RA): Celestial coordinate which is equivalent to the longitude of an object on Earth.
Right Ascension
the amount of time that passes between the rising of Aries and another celestial object. Right ascension is one unit of measure for locating an object in the sky.
Rima
a fissure.
Right ascension (R.A.). The angular distance of a celestial body from the Vernal Equinox, measured eastwards. This is one of the equatorial system of co-ordinates and it is measured in hours, minutes and seconds.
Right Ascension - Angular distance of a body along the celestial equator from the vernal equinox eastward to the point on the equator nearest the body. Right ascension is analogous to longitude in the terrestrial coordinate system ...
Right Ascension is similar to longitude on the Earth, however it is numbered differently. Longitude starts at 0 degrees at the Prime Meridian and goes to 180 degree East or 180 degrees West. Since the Earth is a sphere, 180 E is equal to 180 W.
Right Ascension -- The angular distance of a celestial object measured in hours, minutes, and seconds along the celestial equator eastward from the vernal equinox.
3 : Right ascension is the sky's equivalent to the Earth's ...
latitude.
longitude.
altitude.
meridian.
Right Ascension refers to the angular distance of a star measured east from a common point. That point was chosen by Hipparchus two thousand years ago. He used the point at which the sun was located at the vernal equinox.
right ascension: the celestial equivalent of longitude, denoting how far (in 15 degree wide hours) an object lies east of the Sun's location during the March equinox.
Right Ascension: 22 hours
Declination: 20 degrees
Visible between latitudes 90 and -60 degrees ...
Right Ascension (RA)
A coordinate used by astronomers to locate stars and other celestial objects in the sky.
right ascension, celestial coordinate system
geographic coordinates, ecliptic
Setting circles
Declination is used in some contexts that rule out astronomical declination, to mean the same as magnetic declination.
RIGHT ASCENSION
Right ascension is a that is used to measure the degrees of longitude on the on the . Zero degrees of right ascension is the position of the Sun during the (March 21).
RIGHT ASCENSION
Right ascension is a celestial coordinate that is used to measure the degrees of longitude on the on the celestial sphere. Zero degrees of right ascension is the position of the Sun during the vernal (spring) equinox (March 21).
right ascension: This is the angular distance from the vernal equinox eastward along the celestial equator to the circle used to measure declination. Right ascension corresponds to longitude on earth.
right ascension (RA) - (n.)
The east-west coordinate in the equatorial coordinate system.
RA: Right Ascension & Declination of the midpoints of the constellations. h m
DEC: d m
Quad 'Quad' designates the quadrant of the sky as N for North or S for South, Quadrant 1 through 4.
The Right Ascension of the mean equinox (see Mean Equator; Equinox) referred to the true equator and equinox; apparent sidereal time minus mean sidereal time. (see Apparent Place; Mean Place) [S92]
Equation of State ...
The right ascension is different from the longitude. Instead of running from -180° to +180° like the longitude, the right ascension runs from 0 hour to 24 hours from west to east.
The units of right ascension were originally defined to assist astronomical observation, but the names are rather unfortunate, as these are angular measures, not units of time.
Balancing the Right Ascension Axis
Next, we want to tighten the Declination Axis screw, and loosen the other one, for balancing the Right Ascension Axis. The Right Ascension, or R/A axis, is the one that your weight is screwed into.
right ascension (RA): position on the celestial sphere measured with respect to the vernal equinox position on the celestial equator. It is a projection of longitude lines onto the sky and converted to time units.
Also shown is the right ascension and declination of the radiant, and a nearby bright star. This latter may help give a quick idea of where the radiant is.
Angular distance east of the vernal equinox, through 24 hours, is right ascension. sidereal month The average period of revolution of the moon with respect to the stars, a period of 27 days 7 hours 43 minutes 11.
"RA" is "right ascension (east-west position), "Dec" is "declination," north-south position.
radiant the point in the sky from which meteor showers appear to originate retrograde westward motion in the sky revolution the movement in an orbit around another body right ascension the angular distance around the sky parallel to ...
Astronomical Union Circulars and the Lunar and Planetary Institute to identify papers referring to a given object, and can also search by object position, listing papers which concern objects within a 10 arcminute radius of a given Right Ascension ...
The second movie shows the effect of the changing alignment on the declination and Right Ascension system.
Try to list your objects based on proximity to one another, as opposed to listing them by the Right Ascension.
Positions of astronomical objects are described by their right ascension or RA (the angle eastward from the vernal equinox) and declination or DEC (the angle above or below the celestial equator).
Corresponding to longitude, we have right ascension which is measured eastwards (never westwards) round the sky. The zero-point of right ascension, corresponding to Greenwich, is a point with the mysterious name of The First Point Of Aries.
Right Ascension (RA) and Declination (Dec)
These are the coordinates that astronomers use to precisely locate stars in the sky.
This axis is called the Polar or Right Ascension Axis. The other axis permits north-south motion and is called the Declination Axis. By attaching a set of gears and a motor to the R.A. axis, we can follow the sky with ease.
Having the same right ascension or, more precisely, the same longitude as the sun.
Declination
A coordinate which, along with Right Ascension, may be used to locate any position in the sky. Declination is analogous to latitude for locating positions on the Earth, and ranges from +90 degrees to -90 degrees.
annual variation
The changes in the right ascension and declination of a star due to annual precession and proper motion.
Related category
- CELESTIAL MECHANICS ...
CELESTIAL COORDINATES
Celestial coordinates are pairs of numbers (right ascension and declination) which are used to locate objects on the celestial sphere. They are similar to the coordinates of longitude and latitude on Earth.
...
An ephemeris is a tabulation of computed positions and velocities (and/or various derived quantities such as right ascension and declination) of an orbiting body at specific times. The plural form of ephemeris is ephemerides.
 See also: Sky, Declination, Star, Degree, Latitude
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