The classification of star according to the appearance of their spectra. Spectral classification is indicated with the letters and the numbers 0 to 9. The letters used are O, B, A, F, G, K, M, often remembered with the mnemonic "Oh be a fine girl (guy), kiss me," and they are assigned to stars in order of decreasing effective temperature. The colors of stars are dictated by their effective temperature, so that an O-star spectrum is brightest at the blue end, while the M-star spectrum is brightest at the red end.
Stars can be classified according to key characteristics in their spectra, mainly the presence and strength of spectral lines. The main spectral classes, in sequence from hottest to coolest are: , , , , , , . Each class is further subdivided into ten subdivisions from 0(hottest) to 9 (coolest). Our Sun is a G2 star.
(or type) The classification of stars according to their temperatures using the characteristics of their spectra; the types are 0 B A F G K M.
classification of stars based on the relative strengths of spectral lines. The sequence runs OBAFGKM in decreasing order of surface temperature (note, however, that it is the lines and not the temperature which define the class), with subdivisions 0-9 in each class (e.g. the Sun is class G2, meaning that it is towards the hot end of class G). The system was devised at Harvard University and is sometimes called the Harvard class.
The spectral class of a star is characterised by the absorption and emission lines that are found in its atmosphere. Each spectral class corresponds to a temperature and is denoted by a letter, from O the hottest and more massive stars to M for the coldest and smallest stars. A mnemonic to remember the series of spectral types is: 'Oh Be A Fine Girl (or Guy) Kiss Me' = OBAFGKM. A new class of stars, designated L, has recently been detected. A spectral class is subdivided into subclasses, designated by a number (0-9). See Hertzsprung-Russell (HR) diagram.
A class which is developed on the basis of the pixel spectral, or radiance, data and/or channels derived from radiance data. In terms of thematic mapping all the pixels which fall into a spectral class are interactively overlaid with a distinct colour to aid in interpretation. Harrison & Jupp, 1990.
Classification scheme, based on the strength of stellar spectral lines, which is an indication of the temperature of a star.
the designation of a star based on its spectrum, which is determined by its surface temperature
the classification of stars according to the principle features in their spectra.
Spectral classes are groups of stars that have similar characteristic emission lines in their spectra (indicating that they have similar compositions).
Stars are grouped into different "spectral classes" inAccordance with their surface temperature. TheHottest stars are class O and B, the coolest are class S. The Sun, with a surface temperature of about 6000K, is class G.
A classification scheme that groups stars according to their spectral lines or surface temperatures.
A classification scheme that groups stars according to their surface temperatures and spectral features.
