# Absolute Magnitude and Absolute Bolometric Magnitude

What is the difference between Absolute Magnitude and Absolute Bolometric Magnitude, is it a case of multiply one by a constant to get the other? Can you give an example for a star, say Vega?

• Sorry, no homework. – AtmosphericPrisonEscape Jan 29 '17 at 16:34
• Homework is accepted if you 1. self-identify as homework. 2. Clearly describe what research you have done already. 3. Clearly identify a specific problem – James K Jan 29 '17 at 16:48
• Not homework, I had another question open where Bolometric Magnitude was mentioned by James that I decided to not ask there but ask in a different question. – MiscellaneousUser Jan 29 '17 at 19:18

## 1 Answer

From the page titled, "Absolute Magnitude" and with the disclaimer on that page "not about the magazine," [emphasis mine to aid in finding the info]

Absolute magnitude is the measure of intrinsic brightness of a celestial object. It is the hypothetical apparent magnitude of an object at a standard distance of exactly 10 parsecs (32.6 light years) from the observer, assuming no astronomical extinction of starlight. This places the objects on a common basis and allows the true energy output of astronomical objects to be compared without the distortion introduced by distance. As with all astronomical magnitudes, the absolute magnitude can be specified for different wavelength intervals; for stars the most commonly quoted absolute magnitude is the absolute visual magnitude, which uses only the visual (V) band of the spectrum (UBV system). Also commonly used is the absolute bolometric magnitude, which is the total luminosity expressed in magnitude units that takes into account energy radiated at all wavelengths, whether visible or not.

So in short, AbsMag is Visual Luminosity and AbsBol is Total Luminosity, Visual and Otherwise. (from comment by MiscellaneousUser)

• So in short, AbsMag is Visual Luminosity and AbsBol is Total Luminosity, Visual and Otherwise. – MiscellaneousUser Jan 30 '17 at 19:44