BEAUTY: 
BRAGGING RIGHTS: A beautiful sight
HOW EASY IS IT TO SEE? Telescope required
BEST TIME TO SEE IT: Winter (in Monoceros)
TYPE: Diffuse Nebula DISCOVERED: 1783 by William Herschel
Hidden complexity. Most nebulae change slowly, if at all, but this object, a small fan-shaped nebula in the Monoceros constellation, changes from month to month, like a slow-motion film of a flaming torch. We don’t know for sure what’s causing the phenomena, but astronomers believe a binary star is responsible. A large star—10 times heavier than our sun—is pulling gas from its companion, and emitting fierce jets of gas and radiation as it consumes its meal. Filaments of gas spew out—possibly aligned on magnetic field lines—and cast moving shadows visible all around the nebula. To find it, start at Xi Geminorum and move down to 15 Monocerotis, which is part of the Christmas Tree Cluster. Continue moving on the same line another 1¼ degrees and you’ll reach Hubble’s Nebula. The nebula is faint, however, so dark skies and averted vision are required.
