Pease 1 is a

planetary nebula A planetary nebula (PN, plural PNe) is a type of emission nebula consisting of an expanding, glowing shell of ionized gas ejected from red giant stars late in their lives. The term "planetary nebula" is a misnomer because they are unrelated to ...

located within the

globular cluster A globular cluster is a spheroidal conglomeration of stars. Globular clusters are bound together by gravity, with a higher concentration of stars towards their centers. They can contain anywhere from tens of thousands to many millions of membe ...

M15 M15 or M-15 may refer to: In science * Messier 15 (M15), a globular cluster in the constellation Pegasus In firearms and military equipment * M15 mine, a United States anti-tank mine * M15 rifle, a variant of the M14, a United States military rif ...

33,600

light years A light-year, alternatively spelled light year, is a large unit of length used to express astronomical distances and is equivalent to about 9.46 trillion kilometers (), or 5.88 trillion miles ().One trillion here is taken to be 1012 ...

away in the

constellation A constellation is an area on the celestial sphere in which a group of visible stars forms Asterism (astronomy), a perceived pattern or outline, typically representing an animal, mythological subject, or inanimate object. The origins of the e ...

Pegasus Pegasus ( grc-gre, Πήγασος, Pḗgasos; la, Pegasus, Pegasos) is one of the best known creatures in Greek mythology. He is a winged divine stallion usually depicted as pure white in color. He was sired by Poseidon, in his role as hor ...

. It was the first planetary nebula known to exist within a globular cluster when it was discovered in 1928 (for

Francis G. Pease Francis Gladheim Pease (January 14, 1881 – February 7, 1938) was an American astronomer. He joined the Yerkes Observatory in Wisconsin, where he was an observer and an optician. There he assisted George W. Ritchey who built many of America's f ...

), and just four more have been found (in other clusters) since. At magnitude 15.5, it requires telescopes with an aperture of at least to be detected.

References

External links

Pease 1: Planetary Nebula in Messier 15, SEDS Messier pages
Planetary nebulae Pegasus (constellation) {{nebula-stub