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Below there are lists the nearest stars separated by spectral type. The scope of the list is still restricted to the main sequence spectral types: M, K, F, G, A, B and O. It may be later expanded to other types, such as S, D or C. The Alpha Centauri star system is the closest star system to the Sun.
[c] [11] Some of the most massive stars lie within this spectral class. O-type stars frequently have complicated surroundings that make measurement of their spectra difficult. O-type spectra formerly were defined by the ratio of the strength of the He II λ4541 relative to that of He I λ4471, where λ is the radiation wavelength. Spectral type ...
K-type main-sequence stars are about three to four times as abundant as G-type main-sequence stars, making planet searches easier. [17] K-type stars emit less total ultraviolet and other ionizing radiation than G-type stars like the Sun (which can damage DNA and thus hamper the emergence of nucleic acid based life). In fact, many peak in the red.
The Henry Draper Catalogue (HD) is an astronomical star catalogue published between 1918 and 1924, giving spectroscopic classifications for 225,300 stars; it was later expanded by the Henry Draper Extension (HDE), published between 1925 and 1936, which gave classifications for 46,850 more stars, and by the Henry Draper Extension Charts (HDEC), published from 1937 to 1949 in the form of charts ...
Any planet in orbit around a red dwarf would have to huddle very close to its parent star to attain Earth-like surface temperatures; from 0.3 AU (just inside the orbit of Mercury) for a star like Lacaille 8760, to as little as 0.032 AU for a star like Proxima Centauri [89] (such a world would have a year lasting just 6.3 days). At those ...
• Notes = Common name(s) or alternate name(s); comments; notable properties [for example: multiple star status, range of variability if it is a variable star, exoplanets, etc.] Notes ^ It was commonly with δ Peg by Bayer .
Beta Cassiopeiae (β Cassiopeiae, abbreviated Beta Cas or β Cas), officially named Caph / ˈ k æ f /, [12] [13] is a Delta Scuti variable star in the constellation of Cassiopeia. It is a giant star belonging to the spectral class F2. The white star of second magnitude (+2.28 mag, variable) has an absolute magnitude of +1.3 mag.
The luminosity class 'Ia' represents a bright supergiant star that has exhausted the supply of hydrogen at its core and evolved away from the main sequence. Saiph has a strong stellar wind and is losing mass at the rate of 9.0 × 10 −7 times the mass of the Sun per year, or the equivalent of the Sun's mass every 1.1 million years.