spiral galaxy
Spiral galaxies form a class of galaxy originally described by Edwin Hubble in his 1936 work ''The Realm of the Nebulae''302 million
light-year
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 ...
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 origins of the e ...
of
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 pa ...
on September 20, 1865 with the 11-inch refractor at
Copenhagen
Copenhagen ( or .; da, København ) is the capital and most populous city of Denmark, with a proper population of around 815.000 in the last quarter of 2022; and some 1.370,000 in the urban area; and the wider Copenhagen metropolitan ar ...
independently found the galaxy again on September 15, 1871 with the 31" reflector at
Marseille Observatory
Marseille Observatory (french: Observatoire de Marseille) 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 gal ...
.
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 pertu ...
. It was classified as a type SN 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,
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 pertu ...
. It was classified as a
type II supernova
A Type II supernova (plural: ''supernovae'' or ''supernovas'') results from the rapid collapse and violent explosion of a massive star. A star must have at least 8 times, but no more than 40 to 50 times, the mass of the Sun () to undergo this ...
.
See also
*
List of NGC objects (1–1000)
This is a list of NGC objects 1–1000 from the New General Catalogue (NGC). The astronomical catalogue is composed mainly of star clusters, nebulae, and galaxies. Other objects in the catalogue can be found in the other subpages of the list of NGC ...
819
__NOTOC__
Year 819 (Roman numerals, DCCCXIX) was a common year starting on Saturday (link will display the full calendar) of the Julian calendar.
Events
By place
Europe
* Spring – Emperor Louis the Pious, Louis I marries Judith ...