The Stellar Distance Based on Magnitude calculator computes the approximate distance to a star based on the apparent magnitude of the star (m) and the absolute magnitude of the star (M).
INSTRUCTIONS: Enter the following:
Stellar Distance (d): The calculator returns the approximate distance to the star in parsecs , light-years, and astronomical units However, this can be automatically converted to other distance units (e.g. kilometers or miles) via the pull-down menu.
The formula for the distance to a star based on it apparent and absolute magnitude is:
d = 10(m-M+5)/5
where:
Apparent Magnitude of a star (m) is an inverse indicator of the starts brightness, where a brighter the star will have a lower number for apparent magnitude. In ancient times, before telescopes, the brightest starts were considered first order in brightness and were hence given a magnitude of one (1). Lesser stars had second order (2) and so on. In ideal circumstances, humans can see magnitude six (6) star. However, such conditions are increasingly rare due to light pollution. In modern times, apparent magnitude is more scientifically measured with sensor and light filters that eliminate light outside of the human visual spectrum with wavelength in the range of 505 to 595 nanometers.
The following list contains the maximum apparent magnitude of major objects:
The Absolute Magnitude of a star (M) is much more indicative on the size of the star and the amount of light being emitted. However, the distance from these stars affect the apparent brightness. For this reason, the absolute magnitude is used, and it indicates how bright the star would appear if it was 10 parsecs away. In this way, it gives a fair and balanced way to compare the light of stars. The following list contains the absolute magnitude of major objects:
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