The discussion centers on the sign convention of bolometric correction (BC) in astronomy, highlighting the confusion surrounding its definition and application. Two primary zero-points exist: one defines the Sun with zero bolometric correction, while the other establishes a positive BC for all stars, reflecting their energy emissions beyond the visual spectrum. The discrepancy arises from different definitions, with some sources like Wikipedia using BC = Mb - Mv, and others like Wolfram Science World using BC = Mv - Mb. Ultimately, the sign of the BC depends on the convention adopted by the astronomer.
PREREQUISITESAstronomers, astrophysicists, and students studying stellar properties and photometry will benefit from this discussion, particularly those interested in the nuances of bolometric correction and its implications in astronomical research.
The difference between the visual and bolometric magnitudes of an object. Two zero-points are in use, which differ by 0.07 mag. One defines the Sun to have zero bolometric correction. The other has its zero-point set so that bolometric corrections for all stars are positive; this is because other stars emit more energy than the Sun at non-visual wavelengths, either in the ultraviolet for hotter stars or the infrared for cooler stars. Confusingly, some authorities define bolometric correction as bolometric magnitude minus visual magnitude, which makes all values negative.