a)All astronomical objects that have exactly the same luminosity.
b)An object for which we are likely to know the true luminosity.
c)An object for which we can easily measure the apparent brightness.
d)Any star for which we know the exact apparent brightness.
e)Any galaxy for which we know the exact apparent brightness.
2007-04-01 16:58:16 · 2 answers · asked by defy 1 in Science & Mathematics ➔ Astronomy & Space
A standard candle is an astronomical object that has a known luminosity. Several important methods of deriving distances in extragalactic astronomy and cosmology are based on standard candles. Comparing its known luminosity (or its derived logarithmic quantity, the absolute magnitude) and its observed brightness (apparent magnitude) the distance to the object can be calculated as
2007-04-01 23:18:49 · answer #1 · answered by paul13051956 3 · 0⤊ 0⤋
Hi. Type 1a supernova explosions have been used as a standard candle for enormous distances. http://en.wikipedia.org/wiki/Supernova#Type_Ia but it is only one of many. Your answer is a.
2007-04-05 15:44:40 · answer #2 · answered by Cirric 7 · 0⤊ 0⤋