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Stellar classification. In astronomy, stellar classification is the classification of stars based on their spectral characteristics. Electromagnetic radiation from the star is analyzed by splitting it with a prism or diffraction grating into a spectrum exhibiting the rainbow of colors interspersed with spectral lines.
Currently most of the objects of mass between 10 9 kg to 10 12 kg (less than 1000 teragrams (Tg)) listed here are near-Earth asteroids (NEAs). The Aten asteroid 1994 WR12 has less mass than the Great Pyramid of Giza, 5.9 × 10 9 kg. For more about very small objects in the Solar System, see meteoroid, micrometeoroid, cosmic dust, and ...
Such a planet would lie within the habitable zone of Proxima Centauri, about 0.023–0.054 AU (3.4–8.1 million km) from the star, and would have an orbital period of 3.6–14 days. [86] A planet orbiting within this zone may experience tidal locking to the star. If the orbital eccentricity of this hypothetical planet were low, Proxima ...
Thus, the Sun occupies 0.00001% (1 part in 10 7) of the volume of a sphere with a radius the size of Earth's orbit, whereas Earth's volume is roughly 1 millionth (10 −6) that of the Sun. Jupiter, the largest planet, is 5.2 AU from the Sun and has a radius of 71,000 km (0.00047 AU; 44,000 mi), whereas the most distant planet, Neptune, is 30 AU ...
A G-type main-sequence star (spectral type: G-V), also often, and imprecisely, called a yellow dwarf, or G star, is a main-sequence star (luminosity class V) of spectral type G. Such a star has about 0.9 to 1.1 solar masses and an effective temperature between about 5,300 and 6,000 K (5,030 and 5,730 °C; 9,080 and 10,340 °F ).
Proxima Centauri, the closest star to the Sun, at a distance of 4.2 ly(1.3 pc), is a red dwarf. A red dwarfis the smallest kind of staron the main sequence. Red dwarfs are by far the most common type of fusingstar in the Milky Way, at least in the neighborhood of the Sun. However, due to their low luminosity, individual red dwarfs cannot be ...
Representative lifetimes of stars as a function of their masses The change in size with time of a Sun-like star Artist's depiction of the life cycle of a Sun-like star, starting as a main-sequence star at lower left then expanding through the subgiant and giant phases, until its outer envelope is expelled to form a planetary nebula at upper right Chart of stellar evolution
List of planet types. From top to bottom: Mercury, Venus without its atmosphere, Earth and the Moon, Mars, Jupiter, Saturn, Uranus, and Neptune in false colour (not to scale) The following is a list of planet types by their mass, orbit, physical and chemical composition, or by another classification. The IAU defines that a planet in the Solar ...