Search results
Results From The WOW.Com Content Network
Right ascension is the celestial equivalent of terrestrial longitude. Both right ascension and longitude measure an angle from a primary direction (a zero point) on an equator. Right ascension is measured from the Sun at the March equinox i.e. the First Point of Aries, which is the place on the celestial sphere where the Sun crosses the ...
Model of the equatorial coordinate system. Declination (vertical arcs, degrees) and hour angle (horizontal arcs, hours) is shown. For hour angle, right ascension (horizontal arcs, degrees) can be used as an alternative. The equatorial coordinate system is a celestial coordinate system widely used to specify the positions of celestial objects.
SIMBAD. data. HD 45166 is a binary consisting of a so-called quasi Wolf–Rayet (qWR) star and a B-type main-sequence star, near the cluster NGC 2244, in the constellation of Monoceros. [5] A quasi Wolf–Rayet star is a star with a spectrum resembling those of true Wolf–Rayet stars, but being less massive and luminous than a true Wolf ...
In this case, the longitude is also called the right ascension of the ascending node (RAAN). The angle is measured eastwards (or, as seen from the north, counterclockwise) from the FPA to the node. [2] [3] An alternative is the local time of the ascending node (LTAN), based on the local mean time at which the spacecraft crosses the equator.
Setting circles consist of two graduated disks attached to the axes – right ascension (RA) and declination (DEC) – of an equatorial mount. [1] The RA disk is graduated into hours, minutes, and seconds. The DEC disk is graduated into degrees, arcminutes, and arcseconds. Since the RA coordinates are fixed onto the celestial sphere, the RA ...
Hour angle. The hour angle is indicated by an orange arrow on the celestial equator plane. The arrow ends at the hour circle of an orange dot indicating the apparent place of an astronomical object on the celestial sphere. In astronomy and celestial navigation, the hour angle is the dihedral angle between the meridian plane (containing Earth's ...
Earth rotates while the ECI coordinate system does not. Earth-centered inertial ( ECI) coordinate frames have their origins at the center of mass of Earth and are fixed with respect to the stars. [ 1] ". I" in "ECI" stands for inertial (i.e. "not accelerating "), in contrast to the "Earth-centered – Earth-fixed" ( ECEF) frames, which remains ...
R136a1. A near-infrared image of the R136 cluster. R136a1 is at the center with R136a2 close by, R136a3 below right, and R136b to the left. R136a1 (short for RMC 136a1) is one of the most massive and luminous stars known, at nearly 200 M☉ and nearly 4.7 million L☉, and is also one of the hottest, at around 46,000 K.