Search results
Results from the WOW.Com Content Network
This glossary of astronomy is a list of definitions of terms and concepts relevant to astronomy and cosmology, their sub-disciplines, and related fields. Astronomy is concerned with the study of celestial objects and phenomena that originate outside the atmosphere of Earth. The field of astronomy features an extensive vocabulary and a ...
Astronomy is a natural science that studies celestial objects and the phenomena that occur in the cosmos. It uses mathematics, physics, and chemistry in order to explain their origin and their overall evolution. Objects of interest include planets, moons, stars, nebulae, galaxies, meteoroids, asteroids, and comets.
CGRO – ( telescope) COMPton TELescope, another name for the Compton Gamma Ray Observatory. COROT – ( telescope) COnvection ROtation and planetary Transits, a space telescope for detecting extrasolar planets. COSMOS – ( observing program) Cosmic Evolution Survey. COSPAR – ( organization) COmmittee on SPAce Research.
A more complex definition of absolute magnitude is used for planets and small Solar System bodies, based on its brightness at one astronomical unit from the observer and the Sun. The Sun has an apparent magnitude of −27 and Sirius, the brightest visible star in the night sky, −1.46. Venus at its brightest is -5.
The ecliptic or ecliptic plane is the orbital plane of Earth around the Sun. [ 1][ 2][ a] From the perspective of an observer on Earth, the Sun's movement around the celestial sphere over the course of a year traces out a path along the ecliptic against the background of stars. [ 3] The ecliptic is an important reference plane and is the basis ...
Introduction. Astronomy is a natural science that studies celestial objects and the phenomena that occur in the cosmos. It uses mathematics, physics, and chemistry in order to explain their origin and their overall evolution. Objects of interest include planets, moons, stars, nebulae, galaxies, meteoroids, asteroids, and comets.
Portion of the Carina Nebula. Around 150 AD, Ptolemy recorded, in books VII–VIII of his Almagest, five stars that appeared nebulous.He also noted a region of nebulosity between the constellations Ursa Major and Leo that was not associated with any star. [9]
An equivalent formulation of the old definition of the astronomical unit is the radius of an unperturbed circular Newtonian orbit about the Sun of a particle having infinitesimal mass, moving with a mean motion of 0.017 202 098 95 radians per day. [5] The speed of light in IAU is the defined value c 0 = 299 792 458 m/s of the SI units.