Noun
standard candle (plural standard candles)
(astronomy) Any astronomical object of known absolute magnitude. Its distance can then be calculated from its apparent magnitude.
Novae as distance indicators Nova Eridani 2009 ( apparent magnitude ~8.4) during a full moon Novae have some promise for use as standard candle measurements of distances. Source: Internet
These were typically based on the brightness of the flame from a "standard candle" of defined composition, or the brightness of an incandescent filament of specific design. Source: Internet