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 galaxy, galaxies, star cluste ...
'' identifier for a
lenticular galaxy
A lenticular galaxy (denoted S0) is a Galaxy morphological classification, type of galaxy intermediate between an elliptical galaxy, elliptical (denoted E) and a spiral galaxy in galaxy morphological classification schemes. It contains a large-s ...
in the northern
circumpolar constellation
A circumpolar star is a star that, as viewed from a given latitude on Earth, never sets below the horizon due to its apparent proximity to one of the celestial poles. Circumpolar stars are therefore visible from said location toward the nearest p ...
of
Ursa Major
Ursa Major, also known as the Great Bear, is a constellation in the Northern Sky, whose associated mythology likely dates back into prehistory. Its Latin name means "greater (or larger) bear", referring to and contrasting it with nearby Ursa M ...
. It was discovered by German-British astronomer
William Herschel
Frederick William Herschel ( ; ; 15 November 1738 – 25 August 1822) was a German-British astronomer and composer. He frequently collaborated with his younger sister and fellow astronomer Caroline Herschel. Born in the Electorate of Hanover ...
on 19 March 1790. In the ''Carnegie Atlas of Galaxies'', it is described as being "characterized by an irregular
pattern of dust lanes threaded through the disc in an 'embryonic' spiral pattern indicating a mixed S0/Sa form." It is located near the
Big Dipper
The Big Dipper (American English, US, Canadian English, Canada) or the Plough (British English, UK, Hiberno-English, Ireland) is an asterism (astronomy), asterism consisting of seven bright stars of the constellation Ursa Major; six of them ar ...
, a little to the north of the mid-way point between the stars
Alpha Ursae Majoris
Dubhe is a multiple star system in the northern constellation of Ursa Major. It is formally designated Alpha Ursae Majoris, Latinisation of names, Latinised from α Ursae Majoris, Despite being designated "α" (alpha), it is the sec ...
and
Delta Ursae Majoris
Megrez , also called Delta Ursae Majoris (δ Ursae Majoris, abbreviated Delta UMa, δ UMa), is a star in the northern constellation of Ursa Major. With an apparent magnitude of +3.3, it is the dimmest of the seven stars in ...
. With a
visual magnitude
Apparent magnitude () is a measure of the brightness of a star, astronomical object or other celestial objects like artificial satellites. Its value depends on its intrinsic luminosity, its distance, and any extinction of the object's light ca ...
of 10.7, it can be dimly viewed using a
aperture
In optics, the aperture of an optical system (including a system consisting of a single lens) is the hole or opening that primarily limits light propagated through the system. More specifically, the entrance pupil as the front side image o ...
telescope.
The visual dimensions of this galaxy are with the
major axis
In geometry, the major axis of an ellipse is its longest diameter: a line segment that runs through the center and both foci, with ends at the two most widely separated points of the perimeter. The semi-major axis (major semiaxis) is the longe ...
having a
position angle
In astronomy, position angle (usually abbreviated PA) is the convention for measuring angles on the sky. The International Astronomical Union defines it as the angle measured relative to the Celestial pole, north celestial pole (NCP), turning pos ...
of 85°. The galaxy is being viewed nearly edge-on, with an inclination of 18° to the
line of sight
The line of sight, also known as visual axis or sightline (also sight line), is an imaginary line between a viewer/ observer/ spectator's eye(s) and a subject of interest, or their relative direction. The subject may be any definable object taken ...
from the Earth. It is moving away from us with a
radial velocity
The radial velocity or line-of-sight velocity of a target with respect to an observer is the rate of change of the vector displacement between the two points. It is formulated as the vector projection of the target-observer relative velocity ...
of . The estimated visual luminosity of the galaxy is L⊙, or 42 billion times the brightness of the Sun. Photographs show a tightly wound spiral pattern in the galactic disk, with three dust lanes—the southern side of the galaxy appears dimmer due to the dust configuration. The mass of the free gas and dust in the galaxy is about M⊙ and M⊙, respectively, with around M⊙ of the gas being in an ionized state.
This is a type of
active galaxy
An active galactic nucleus (AGN) is a compact region at the center of a galaxy that emits a significant amount of energy across the electromagnetic spectrum, with characteristics indicating that this luminosity is not produced by the stars. Such e ...
emission lines
A spectral line is a weaker or stronger region in an otherwise uniform and continuous spectrum. It may result from emission or absorption of light in a narrow frequency range, compared with the nearby frequencies. Spectral lines are often used ...
of
ionized gas
Plasma () is a state of matter characterized by the presence of a significant portion of charged particles in any combination of ions or electrons. It is the most abundant form of ordinary matter in the universe, mostly in stars (including the ...
in the region of its nucleus. Chemically, the stars at the center of the nucleus have a higher
metallicity
In astronomy, metallicity is the Abundance of the chemical elements, abundance of Chemical element, elements present in an object that are heavier than hydrogen and helium. Most of the normal currently detectable (i.e. non-Dark matter, dark) matt ...
than in the neighboring regions. It appears that there is a tilted disk of stars orbiting the nucleus within a radius of . The
galactic bulge
In astronomy, a galactic bulge (or simply bulge) is a tightly packed group of stars within a larger star formation. The term almost exclusively refers to the group of stars found near the center of most spiral galaxies (see ''galactic spheroid'' ...
itself appears triaxial with the ionized gas concentrated near the center of this bulge region. Images of the galaxy with the
Hubble Space Telescope
The Hubble Space Telescope (HST or Hubble) is a space telescope that was launched into low Earth orbit in 1990 and remains in operation. It was not the Orbiting Solar Observatory, first space telescope, but it is one of the largest and most ...
show a wispy disk of dust on all sides of the nucleus, with what appears to be the tendrilous remains of an ionization cone leading away 4 arc seconds to the northeast. Such features are common in
Seyfert galaxies
Seyfert galaxies are one of the two largest groups of active galactic nucleus, active galaxies, along with quasar host galaxies. They have quasar-like Active galactic nucleus, nuclei (very luminous sources of electromagnetic radiation that are o ...
.
NGC 4036 is a member of the LGG 266
galaxy group
A galaxy group or group of galaxies (GrG) is an aggregation of galaxies comprising about 50 or fewer gravitationally bound members, each at least as luminous as the Milky Way (about 1010 times the luminosity of the Sun); collections of galaxi ...
(Also known as the NGC 4036 Group), along with NGC 4041, IC 758, UGC 7009, and UGC 7019. It is located just 17 arc minutes from NGC 4041, and the two form a pair with a projected separation of around . The NGC 4036 Group is part of the Ursa Major Cloud, which is part of the
Virgo Supercluster
The Local Supercluster (LSC or LS), or Virgo Supercluster is a formerly defined supercluster containing the Virgo Cluster and Local Group, which itself contains the Milky Way and Andromeda galaxies, as well as others. At least 100 galaxy group ...
.
Supernova
One
supernova
A supernova (: supernovae or supernovas) is a powerful and luminous explosion of a star. A supernova occurs during the last stellar evolution, evolutionary stages of a massive star, or when a white dwarf is triggered into runaway nuclear fusion ...
has been observed in NGC 4036. SN 2007gi ( type Ia, mag. 16.3) was discovered by
Kōichi Itagaki
is an amateur astronomer based in Yamagata, the capital city of Yamagata Prefecture in the Tōhoku region of northern Honshu island, Japan. He is responsible for discovering many comets, and over 170 supernovae.HST)