NGC 1, also occasionally referred to as GC 1, UGC 57, PGC 564 or Holm 2a is an intermediate

spiral galaxy Spiral galaxies form a class of galaxy originally described by Edwin Hubble in his 1936 work ''The Realm of the Nebulae''morphological type Sbc, located approximately 210 to 215 million

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 ...

from the

Solar System The Solar SystemCapitalization of the name varies. The International Astronomical Union, the authoritative body regarding astronomical nomenclature, specifies capitalizing the names of all individual astronomical objects but uses mixed "Solar S ...

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 discovered on 30 September 1861 by

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

Observation history

NGC 1 was first observed by Heinrich d'Arrest in 1860 while testing the 11 inch refractor telescope of the

Copenhagen Observatory 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 ...

. He described his discovery as "faint, small, round, between 11th and 14th magnitude stars" (to the north and south). Herman Schultz also observed NGC 1 three times in 1866 and 1868 using a 9.6 inch

refractor telescope A refracting telescope (also called a refractor) is a type of optical telescope that uses a lens as its objective to form an image (also referred to a dioptric telescope). The refracting telescope design was originally used in spyglasses and as ...

at Upsala. Both of the initial observers missed NGC 2, which is much fainter. NGC 1 appears to be quite close to NGC 2, in reality however, the two objects are far apart and unrelated. NGC 2 was first observed as a "companion" of NGC 1 by

Lawrence Parsons Laurence or Lawrence Parsons may refer to: * Laurence Parsons, 1st Earl of Rosse (1749–1807), Irish peer and politician * Lawrence Parsons, 2nd Earl of Rosse (1758–1841), Irish peer * Lawrence Parsons, 4th Earl of Rosse (1840–1908), Irish pee ...

General

At an estimated 140,000 light-years in diameter, NGC 1 is roughly the same size as our own galaxy, the

Milky Way The Milky Way is the galaxy that includes our Solar System, with the name describing the galaxy's appearance from Earth: a hazy band of light seen in the night sky formed from stars that cannot be individually distinguished by the naked eye ...

, which is believed to be approximately 160,000 light-years across. Although its

apparent magnitude Apparent magnitude () is a measure of the brightness of a star or other astronomical object observed from Earth. An object's apparent magnitude depends on its intrinsic luminosity, its distance from Earth, and any extinction of the object's li ...

of 13.65 lets the galaxy appear too faint to see it in the sky with the naked eye, its

absolute magnitude Absolute magnitude () is a measure of the luminosity of a celestial object on an inverse Logarithmic scale, logarithmic Magnitude (astronomy), astronomical magnitude scale. An object's absolute magnitude is defined to be equal to the apparent mag ...

of -22.08 makes NGC 1 two to three times more luminous than our home galaxy. The galaxy is 4.0 Mly away from the 80,000 light-year wide galaxy UGC 69, its nearest major neighbor. NGC 1 has a visual size of 1.6' × 1.2'. Being classified as a SABbc class galaxy using the

Hubble sequence The Hubble sequence is a morphological classification scheme for galaxies invented by Edwin Hubble in 1926. It is often colloquially known as the Hubble tuning-fork diagram because the shape in which it is traditionally represented resembles a tun ...

and the De Vaucouleurs system as an extension, NGC 1 is a spiral galaxy with the presence of a weak nuclear bar and loosely wound arms. Although the central galaxy is only about 90,000 light-years across, a large, diffuse arm extends eastwards from it, possibly from a past merger. Based on its

redshift In physics, a redshift is an increase in the wavelength, and corresponding decrease in the frequency and photon energy, of electromagnetic radiation (such as light). The opposite change, a decrease in wavelength and simultaneous increase in f ...

of approximately 0.015177 and thus

recessional velocity Recessional velocity is the rate at which an extragalactic astronomical object recedes (becomes more distant) from an observer as a result of the expansion of the universe. It can be measured by observing the wavelength shifts of spectral lines e ...

of 4450 km/s, the distance of the galaxy from the Solar System can be calculated using

Hubble's Law Hubble's law, also known as the Hubble–Lemaître law, is the observation in physical cosmology that galaxies are moving away from Earth at speeds proportional to their distance. In other words, the farther they are, the faster they are moving ...

. Using current observation data, this places the galaxy at approximately 210 to 215 million light-years from Earth, which is in good agreement with redshift-independent distance estimates of 175 to 245 million light years. An opposing measurement of the galaxy's recessional velocity of 2215 km/s would place the galaxy only about 100 million light-years away. However, this is regarded unlikely by most astronomers and believed to be a misattributed value for a different galaxy.

Listing in astronomical catalogues

After being logged as the first object in the General Catalogue, the galaxy is also the first object to be listed in the catalogue's successor, the

New General Catalogue The ''New General Catalogue of Nebulae and Clusters of Stars'' (abbreviated NGC) is an astronomical catalogue of deep-sky objects compiled by John Louis Emil Dreyer in 1888. The NGC contains 7,840 objects, including galaxies, star clusters and ...

. With an original right ascension of at the time of the catalog's compilation (

epoch In chronology and periodization, an epoch or reference epoch is an instant in time chosen as the origin of a particular calendar era. The "epoch" serves as a reference point from which time is measured. The moment of epoch is usually decided by ...

1860), this object had the lowest

right ascension Right ascension (abbreviated RA; symbol ) is the angular distance of a particular point measured eastward along the celestial equator from the Sun at the March equinox to the (hour circle of the) point in question above the earth. When paired w ...

of all the objects in the catalog, making it the first listing in the New General Catalogue as the objects were arranged by right ascension. Since then, the coordinates have shifted, and this object no longer has the lowest right ascension of all the NGC objects.Erdmann, R.E., Jr., ''The Historically Corrected New General Catalogue of Nebulæ and Clusters of Stars'', p12
retrieved
an
archived
13 June 2008. NGC 1 is also listed in the

Uppsala General Catalogue The Uppsala General Catalogue of Galaxies (UGC) is a catalogue of 12,921 galaxies visible from the northern hemisphere. It was first published in 1973. The catalogue includes essentially all galaxies north of declination -02°30' and to a limiting ...

(UGC 57) and in the

Principal Galaxies Catalogue The Catalogue of Principal Galaxies (PGC) is an astronomical catalog published in 1989 that lists B1950 and J2000 equatorial coordinates and cross-identifications for 73,197 galaxies. It is based on the Lyon-Meudon Extragalactic Database (LEDA), ...

(PGC 564).

Observation history

General

Listing in astronomical catalogues

See also