absolute magnitude - translation to ελληνικό
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absolute magnitude - translation to ελληνικό

LOGARITHMIC MEASURE OF THE LUMINOSITY OF A CELESTIAL OBJECT
Bolometric magnitude; Absolute brightness; Absolute Visual Magnitude; Absolute Magnitude; Absolute bolometric magnitude; Intrinsic brightness; Absolute luminosity; Absolute visual magnitude; Absolute magnitude (H)
  • Phase integrals for various values of G

absolute magnitude         
απόλυτο μέγεθος
absolute value         
NONNEGATIVE NUMBER WITH THE SAME MAGNITUDE AS A GIVEN REAL NUMBER
Modulus function; Absolute value (mathematics); Absolute Value; Absolute Value (mathematics); Absolute Values; Absolute values; Absolute Square; Abs(); Modulus of complex number; Fabs(); Math.fabs; Module of a complex number; Complex abs; Absolute value of number; Magnitude of Complex Number; Absolute value of a complex number; Modulus of a complex number; Magnitude of a complex number; Abs(x)
απόλυτη αξία, απόλυτη τιμή
απόλυτο μέγεθος         
absolute magnitude

Ορισμός

absolute magnitude
¦ noun Astronomy the magnitude (brightness) of a celestial object as it would be seen at a standard distance of 10 parsecs.

Βικιπαίδεια

Absolute magnitude

Absolute magnitude (M) is a measure of the luminosity of a celestial object on an inverse logarithmic astronomical magnitude scale. An object's absolute magnitude is defined to be equal to the apparent magnitude that the object would have if it were viewed from a distance of exactly 10 parsecs (32.6 light-years), without extinction (or dimming) of its light due to absorption by interstellar matter and cosmic dust. By hypothetically placing all objects at a standard reference distance from the observer, their luminosities can be directly compared among each other on a magnitude scale.

As with all astronomical magnitudes, the absolute magnitude can be specified for different wavelength ranges corresponding to specified filter bands or passbands; for stars a commonly quoted absolute magnitude is the absolute visual magnitude, which uses the visual (V) band of the spectrum (in the UBV photometric system). Absolute magnitudes are denoted by a capital M, with a subscript representing the filter band used for measurement, such as MV for absolute magnitude in the V band.

The more luminous an object, the smaller the numerical value of its absolute magnitude. A difference of 5 magnitudes between the absolute magnitudes of two objects corresponds to a ratio of 100 in their luminosities, and a difference of n magnitudes in absolute magnitude corresponds to a luminosity ratio of 100n/5. For example, a star of absolute magnitude MV = 3.0 would be 100 times as luminous as a star of absolute magnitude MV = 8.0 as measured in the V filter band. The Sun has absolute magnitude MV = +4.83. Highly luminous objects can have negative absolute magnitudes: for example, the Milky Way galaxy has an absolute B magnitude of about −20.8.

An object's absolute bolometric magnitude (Mbol) represents its total luminosity over all wavelengths, rather than in a single filter band, as expressed on a logarithmic magnitude scale. To convert from an absolute magnitude in a specific filter band to absolute bolometric magnitude, a bolometric correction (BC) is applied.

For Solar System bodies that shine in reflected light, a different definition of absolute magnitude (H) is used, based on a standard reference distance of one astronomical unit.