Messier 78 or M78, also known as NGC 2068, is a reflection nebula 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 ...

Orion. It was discovered by

Pierre Méchain Pierre François André Méchain (; 16 August 1744 – 20 September 1804) was a French astronomer and surveyor who, with Charles Messier, was a major contributor to the early study of deep-sky objects and comets. Life Pierre Méchain was born i ...

in 1780 and included by

Charles Messier Charles Messier (; 26 June 1730 – 12 April 1817) was a French astronomer. He published an astronomical catalogue consisting of 110 nebulae and star clusters, which came to be known as the ''Messier objects''. Messier's purpose f ...

in his catalog of

comet A comet is an icy, small Solar System body that, when passing close to the Sun, warms and begins to release gases, a process that is called outgassing. This produces a visible atmosphere or coma, and sometimes also a tail. These phenomena ar ...

-like objects that same year. M78 is the brightest diffuse reflection nebula of a group of nebulae that includes

NGC 2064 NGC 2064 is a reflection nebula in the constellation Orion (constellation), Orion. It was discovered on January 11, 1864 by Heinrich d'Arrest. It is part of a group of nebulae, that also includes Messier 78, NGC 2071 and NGC 2067. External link ...

NGC 2067 NGC 2067 is a reflection nebula in the constellation Orion. It was discovered in 1876 by Wilhelm Tempel. It is part of a group of nebulae that also includes Messier 78, NGC 2071 and NGC 2064. External links The Interactive NGC Catalog Onli ...

and

NGC 2071 NGC 2071 is a reflection nebula in the constellation Orion. It was discovered on January 1, 1784, by William Herschel. It is part of a group of nebulae that also includes Messier 78, NGC 2064, and NGC 2067 NGC 2067 is a reflection nebula in ...

. This group belongs to the Orion B molecular cloud complex and is about distant from Earth. M78 is easily found in small

telescope A telescope is a device used to observe distant objects by their emission, absorption, or reflection of electromagnetic radiation. Originally meaning only an optical instrument using lenses, curved mirrors, or a combination of both to observe ...

s as a hazy patch and involves two stars of 10th and 11th

magnitude Magnitude may refer to: Mathematics *Euclidean vector, a quantity defined by both its magnitude and its direction *Magnitude (mathematics), the relative size of an object *Norm (mathematics), a term for the size or length of a vector *Order of ...

. These two

B-type star A B-type main-sequence star (B V) is a main-sequence (hydrogen-burning) star of spectral type B and luminosity class V. These stars have from 2 to 16 times the mass of the Sun and surface temperatures between 10,000 and 30,000 K. B-type star ...

s, and , are responsible for making the cloud of dust in M78 visible by reflecting their light. The M78 cloud contains a cluster of stars that is visible in the

infrared Infrared (IR), sometimes called infrared light, is electromagnetic radiation (EMR) with wavelengths longer than those of visible light. It is therefore invisible to the human eye. IR is generally understood to encompass wavelengths from around ...

. Due to gravity, the molecular gas in the nebula has fragmented into a hierarchy of clumps, whose cores have masses ranging from to . About 45

variable star A variable star is a star whose brightness as seen from Earth (its apparent magnitude) changes with time. This variation may be caused by a change in emitted light or by something partly blocking the light, so variable stars are classified as ...

s of the ''T Tauri'' type, young stars still in the process of formation, are members as well. Similarly, 17

Herbig–Haro object Herbig–Haro (HH) objects are bright patches of nebulosity associated with newborn stars. They are formed when narrow jets of partially ionised gas ejected by stars collide with nearby clouds of gas and dust at several hundred kilometres per s ...

s are known in M78.

Gallery

VISTA views Messier 78.jpg,

VISTA Vista usually refers to a distant view. Vista may also refer to: Software *Windows Vista, the line of Microsoft Windows client operating systems released in 2006 and 2007 * VistA, (Veterans Health Information Systems and Technology Architecture) ...

image of Messier 78. Making a Spectacle of Star Formation in Orion.jpg,

Spitzer Spitzer is a surname. Notable people with the surname include: * Andre Spitzer (1945–1972), Israeli fencing coach and victim of the Munich massacre * Bernard Spitzer (1924–2014), American real estate developer and philanthropist, father of Eli ...

image of Messier 78.

References

External links

*
SEDS: Starforming Nebula M78
*
NightSkyInfo.com – M78
*

Astronomy Picture of the Day Astronomy Picture of the Day (APOD) is a website provided by NASA and Michigan Technological University (MTU). According to the website, "Each day a different image or photograph of our universe is featured, along with a brief explanation writt ...

*
M78 Wide Field
2009 November 26 *

2010 March 2 * {{Sky, 05, 46.7, 00, +, 00, 03, 00, 1600 Messier 078 Messier 078 Orion–Cygnus Arm Messier 078 078 Messier 078 Astronomical objects discovered in 1780 Discoveries by Pierre Méchain

Gallery

See also

References

External links