Absolute Magnitude

(Last edited: Thursday, 31 August 2023, 11:44 AM)


Short Definition:

Absolute magnitude is the measurement of the brightness of celestial bodies using inverse logarithmic calculations in astronomical calculations and expressed as a mathematical value. This process involves mathematically expressing their luminosity, as a hypothesis, by placing objects at an equal distance from the observer (10 parsecs that equals to 32.6 light years).

Detailed Definition:

Absolute magnitude is also called absolute visual magnitude, which is a hypothesis that predicts the mathematical calculation of the luminosity of different celestial bodies, taking into account fixed distances, and comparing the luminosities of these objects. The mathematical formula used to calculate this luminosity is as follows;

Mv: Absolute magnitude

m: Apparent magnitude

d: Distance in 10 parsecs

Mv = m – 2.5 log [d/10]²

The apparent magnitude here, on an inverse scale, indicates how bright celestial objects appear to our eyes. Because it's an inverted scale, high numbers indicate dim objects and low numbers indicate bright objects. The brightest object known and measured on this scale has a value of -10, while the star Sirius has a luminosity of 1.4, and our sun has a luminosity of 4.8.


Absolute -from old Latin (absolūtus)

(Absolute – Wiktionary. (n.d.). https://en.wiktionary.org/wiki/absolute)

Magnitude -from old Latin (Magnus)

(Magnitude – Wiktionary. (n.d.). https://en.wiktionary.org/wiki/magnitude)

Sample Sentence(s):

‘’When comet 289P/Blanpain was discovered in 1819, its absolute magnitude was estimated as {\displaystyle M_{1}=8.5}{\displaystyle M_{1}=8.5}’’

(Wikipedia contributors. (2023, January 13). Absolute magnitude. Wikipedia. https://en.wikipedia.org/wiki/Absolute_magnitude)

‘’Colour–magnitude diagram, in astronomy, graph showing the relation between the absolute magnitudes (brightnesses) of stars and their colours, which are closely related to their temperatures and spectral types.’’

(The Editors of Encyclopaedia Britannica. (1998, July 20). Colour–magnitude diagram | astronomy. Encyclopedia Britannica. https://www.britannica.com/science/colour-magnitude-diagram)

Translations of Terms/Concepts into Partner Languages:


Magnitude absolue


Absolute Helligkeit


wielkość absolutna


Absolut magnitud


Mutlak Kadir

Links to Videos/Articles:

Absolute magnitude | astronomy. (n.d.-a). Encyclopaedia Britannica. https://www.britannica.com/science/absolute-magnitude

Absolute Magnitude | COSMOS. (n.d.-a). https://astronomy.swin.edu.au/cosmos/a/Absolute+Magnitude

Apparent and Absolute Magnitudes. (n.d.-b). https://www.phys.ksu.edu/personal/wysin/astro/magnitudes.html

Michel van Biezen. (2014, April 9). Astronomy - Measuring Distance, Size, and Luminosity (18 of 30) Absolute Magnitude [Video]. YouTube. https://www.youtube.com/watch?v=yfsUhOPCMaM

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