NGC 819 is a

spiral galaxy Spiral galaxies form a galaxy morphological classification, class of galaxy originally described by Edwin Hubble in his 1936 work ''The Realm of the Nebulae''

light-year A light-year, alternatively spelled light year (ly or lyr), is a unit of length used to express astronomical distances and is equal to exactly , which is approximately 9.46 trillion km or 5.88 trillion mi. As defined by the International Astr ...

s away from Earth 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 first constellati ...

Triangulum Triangulum is a small constellation in the northern sky. Its name is Latin for "triangle", derived from its three brightest stars, which form a long and narrow triangle. Known to the ancient Babylonians and Greeks, Triangulum was one of the 48 ...

. It forms a visual pair with the galaxy NGC 816 5.7' WNW.

Discovery

NGC 819 was discovered by German astronomer

Heinrich Louis d'Arrest Heinrich Louis d'Arrest (13 August 1822 – 14 June 1875; ) was a German astronomer, born in Berlin. His name is sometimes given as Heinrich Ludwig d'Arrest. Biography While still a student at the University of Berlin, d'Arrest was par ...

on September 20, 1865 with the 11-inch refractor at

Copenhagen Copenhagen ( ) is the capital and most populous city of Denmark, with a population of 1.4 million in the Urban area of Copenhagen, urban area. The city is situated on the islands of Zealand and Amager, separated from Malmö, Sweden, by the ...

Édouard Stephan Édouard Jean-Marie Stephan (31 August 1837 – 31 December 1923) was a French astronomer. His surname is sometimes spelled Stéphan in some literature, but this is apparently erroneous. He was born in Sainte Pezenne (today one of the districts o ...

independently found the galaxy again on September 15, 1871 with the 31" reflector at

Marseille Observatory Marseille Observatory () is an astronomical observatory located in Marseille, France, with a history that goes back to the early 18th century. In its 1877 incarnation, it was the discovery site of a group of galaxies known as Stephan's Quintet, ...

Supernovae

Supernova SN 2007hb was discovered in NGC 819 on August 24, 2007 by

Nearby Supernova Factory The Nearby Supernova Factory (SNfactory) is a collaborative experiment led by Greg Aldering, designed to collect data on more Type Ia supernovae than have ever been studied in a single project before, and by studying them, to increase understandin ...

. SN 2007hb had a magnitude of about 19.5 and was located at RA 02h08m34.0s, DEC +29d14m14s,

J2000.0 In astronomy, an epoch or reference epoch is a moment in time used as a reference point for some time-varying astronomical quantity. It is useful for the celestial coordinates or orbital elements of a celestial body, as they are subject to pe ...

. It was classified as a type Ib/c supernova. Supernova SN 2016hkn was discovered in NGC 819 on October 22, 2016 by Fabio Briganti. SN 2014bu had a magnitude of about 17.2 and was located at RA 02h08m34.2s, DEC +29d14m11s,

. It was classified as a

type II supernova A Type II supernova or SNII (plural: ''supernovae'') results from the rapid collapse and violent explosion of a massive star. A star must have at least eight times, but no more than 40 to 50 times, the mass of the Sun () to undergo this type ...

. Supernova SN 2020mbe ( typeIc, mag. 18.6) was discovered in NGC 819 on 10 January 2020.

References

External links

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SEDS
{{DEFAULTSORT:NGC 819 Spiral galaxies Triangulum 0819 008174 Astronomical objects discovered in 1865 NGC 819 02056+2859 01632

Discovery

Supernovae

See also

References

External links