M1-92

M1-92 (Minkowski 92), also known as Minkowski’s Footprint or the Footprint Nebula, is a bipolar protoplanetary nebula in the constellation of Cygnus. It is a type of reflection nebula, visible only by light reflected from the central star. The central star is not yet a white dwarf but is quickly becoming one. In a few thousand years the star will be hot enough to emit vast quantities of ultraviolet radiation that will ionize the nebula surrounding it, making it a fully fledged planetary nebula.

M1-92 was discovered by Rudolph Minkowski in 1946. It was imaged by the Very Large Array (VLA) in 1983 and by Hubble Space Telescope in 1996. The object is 8,000 light-years away from Earth, and has a radial velocity of -7.086 kilometers (-4.4 miles) a second. Its axis is tilted 35 degrees from our line of sight. It is 11 by 6 arcseconds in angular size. It is 0.42 light-years in diameter and shines at 10,000 solar luminosities.