21 relations: Astrometry, Astronomical unit, Brown dwarf, Cepheid variable, Doppler effect, Hipparcos, Hyades (star cluster), Minute and second of arc, Parallax, Parsec, Perspective (graphical), Pleiades, Proper motion, Radial velocity, RR Lyrae, Star cluster, Stellar parallax, The Astrophysical Journal, Vanishing point, 2M1207, 2M1207b.
Astrometry is the branch of astronomy that involves precise measurements of the positions and movements of stars and other celestial bodies.
The astronomical unit (symbol: au, ua, or AU) is a unit of length, roughly the distance from Earth to the Sun.
Brown dwarfs are substellar objects that occupy the mass range between the heaviest gas giant planets and the lightest stars, having masses between approximately 13 to 75–80 times that of Jupiter, or approximately to about.
A Cepheid variable is a type of star that pulsates radially, varying in both diameter and temperature and producing changes in brightness with a well-defined stable period and amplitude.
The Doppler effect (or the Doppler shift) is the change in frequency or wavelength of a wave in relation to observer who is moving relative to the wave source.
Hipparcos was a scientific satellite of the European Space Agency (ESA), launched in 1989 and operated until 1993.
The Hyades (Greek Ὑάδες, also known as Melotte 25 or Collinder 50) is the nearest open cluster and one of the best-studied star clusters.
A minute of arc, arcminute (arcmin), arc minute, or minute arc is a unit of angular measurement equal to of one degree.
Parallax is a displacement or difference in the apparent position of an object viewed along two different lines of sight, and is measured by the angle or semi-angle of inclination between those two lines.
The parsec (symbol: pc) is a unit of length used to measure large distances to astronomical objects outside the Solar System.
Perspective (from perspicere "to see through") in the graphic arts is an approximate representation, generally on a flat surface (such as paper), of an image as it is seen by the eye.
The Pleiades (also known as the Seven Sisters and Messier 45), are an open star cluster containing middle-aged, hot B-type stars located in the constellation of Taurus.
Proper motion is the astronomical measure of the observed changes in the apparent places of stars or other celestial objects in the sky, as seen from the center of mass of the Solar System, compared to the abstract background of the more distant stars.
The radial velocity of an object with respect to a given point is the rate of change of the distance between the object and the point.
RR Lyrae is a variable star in the Lyra constellation, located near the border with the neighboring constellation of Cygnus.
Star clusters are groups of stars.
Stellar parallax is the apparent shift of position of any nearby star (or other object) against the background of distant objects.
The Astrophysical Journal, often abbreviated ApJ (pronounced "ap jay") in references and speech, is a peer-reviewed scientific journal of astrophysics and astronomy, established in 1895 by American astronomers George Ellery Hale and James Edward Keeler.
A vanishing point is a point on the image plane of a perspective drawing where the two-dimensional perspective projections (or drawings) of mutually parallel lines in three-dimensional space appear to converge.
2M1207, 2M1207A or 2MASS J12073346-3932539 is a brown dwarf located in the constellation Centaurus; a companion object, 2M1207b, may be the first extrasolar planetary-mass companion to be directly imaged, and is the first discovered orbiting a brown dwarf.
2M1207b is a planetary-mass object orbiting the brown dwarf 2M1207, in the constellation Centaurus, approximately 170 light-years from Earth.