Albedo used in astronomy are the (V-band) geometric albedo (measuring brightness when illumination comes from directly behind the observer) and the Bond albedo (measuring total proportion of electromagnetic energy reflected). Their values can differ significantly, which is a common source of confusion. In detailed studies, the directional reflectance properties of astronomical bodies are often expressed in terms of the five Hapke parameters which semi-empirically describe the variation of albedo with phase angle, including a characterization of the opposition effect of regolith surfaces. The correlation between astronomical (geometric) albedo, absolute magnitude and diameter is: formula_7, where formula_8 is the astronomical albedo, formula_9
Albedo One Fiction" 2006. "Albedo One" was voted 8th in the Nominations for the Hugo Award under the "Best Semiprozine" category for 2006. Although only the top five in the list are deemed to have earned a Nomination for the Hugo Award under this category, the event is notable as being the first time "Albedo One" has had a presence on the nominations list (and the first time an Irish genre magazine has had a presence). The event is also notable in that "Albedo One" was placed ahead of other well-known magazines such as "Lady Churchill's Rosebud Wristlet", "Postscripts" and "Apex Digest".