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.

Apr 10, 2025 · Stellar classification, scheme for assigning stars to types according to their temperatures as estimated from their spectra. The generally accepted system of stellar classification is a combination of two classification schemes: the Harvard system, which is based on the star’s surface temperature,

Apr 20, 2025 · Star - Spectral Types, Classification, Astronomy: Most stars are grouped into a small number of spectral types. The Henry Draper Catalogue and the Bright Star Catalogue list spectral types from the hottest to the coolest stars (see stellar classification).

Each spectral type is divided into 10 subclasses, A0, A1, A2, ...A9 etc. The spectral types and sub-classes represent a temperature sequence, from hotter (O stars) to cooler (M stars), and from hotter (subclass 0) to cooler (subclass 9).

Stars near the beginning of a given spectral type are referred to as early-type stars (e.g., A0), where those closer to the end are called late-type (e.g., A9). Cannon classified around 200,000 spectra, where the results were collected into the Henry Draper Catalogue.

Spectra are described by Kirchoff's Laws: A hot opaque body, such as a hot, dense gas (or a solid) produces a continuous spectrum – a complete rainbow of colors. A hot, transparent gas produces an emission line spectrum – a series of bright spectral lines against a dark background.

Most light sources can be classified into three main types: continuous, absorption, and emission. A hot, opaque object, like the filament in an incandescent light bulb, emits a continuous spectrum, having light of all wavelengths. A hot, dense gas is another example of an object that emits a continuous spectrum.

What stellar spectral classification is, a history of its development and how to observe these differences in stars for yourself.

Feb 17, 2025 · Spectra are the patterns of light produced when a star’s radiation is split into different wavelengths. By analyzing these patterns, astronomers determine the temperature, chemical composition, and other properties of stars. The modern classification system is known as the Morgan–Keenan (MK) system.

Nov 20, 2024 · The basic Spectral Types are O – B – A – F – G – K – M. Cannon decided to drop several letters and numbers, thus the seemingly unorganized system we employ today. As can be seen in the graphic, the Spectral Type is indicative of …