NGC 3447 is a barred Magellanic

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''

located in the constellation Leo. Its speed relative to the

cosmic microwave background The cosmic microwave background (CMB, CMBR), or relic radiation, is microwave radiation that fills all space in the observable universe. With a standard optical telescope, the background space between stars and galaxies is almost completely dar ...

is 1,405 ± 34 km/s, which corresponds to a

Hubble distance 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 a galaxy is from the Earth, the faster ...

of 20.7 ± 1.5 Mpc (~67.5 million ly). It was discovered by the British

astronomer An astronomer is a scientist in the field of astronomy who focuses on a specific question or field outside the scope of Earth. Astronomers observe astronomical objects, such as stars, planets, natural satellite, moons, comets and galaxy, galax ...

John Herschel Sir John Frederick William Herschel, 1st Baronet (; 7 March 1792 – 11 May 1871) was an English polymath active as a mathematician, astronomer, chemist, inventor and experimental photographer who invented the blueprint and did botanical work. ...

in 1836. NGC 3447 shows a broad HI line. With a surface brightness equal to 15.61 mag/am^2, NGC 3443 is classified as a

low surface brightness galaxy A low-surface-brightness galaxy, or LSB galaxy, is a diffuse galaxy with a surface brightness that, when viewed from Earth, is at least one magnitude lower than the ambient night sky. Most LSBs are dwarf galaxies, and most of their baryonic matt ...

(LSB). LSB galaxies are diffuse galaxies with a surface brightness less than one magnitude lower than that of the ambient night sky. To date, four non-

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 increase in frequency and e ...

measurements yield a distance of 13.730 ± 9.802 Mpc (~44.8 million ly), which is slightly outside the range values of Hubble.

NGC 3447A

NGC 3447A, also known as UGC 6007, is an

irregular galaxy An irregular galaxy is a galaxy that does not have a distinct regular shape, unlike a spiral or an elliptical galaxy. Irregular galaxies do not fall into any of the regular classes of the Hubble sequence, and they are often chaotic in appearan ...

in contact with NGC 3447. It has roughly the same

apparent magnitude Apparent magnitude () is a measure of the Irradiance, 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 (astronomy), ...

, and has a slightly lower

surface brightness In astronomy, surface brightness (SB) quantifies the apparent brightness or flux density per unit angular area of a spatially extended object such as a galaxy or nebula, or of the night sky background. An object's surface brightness depends on ...

. Due to gravitational forces, it has become distorted, showing disrupted

spiral arms Spiral arms are a defining feature of spiral galaxies. They manifest as spiral-shaped regions of enhanced brightness within the galactic disc. Typically, spiral galaxies exhibit two or more spiral arms. The collective configuration of these arms ...

and remnants of its spiral structure, hinting it might have been a spiral galaxy in the past.

Supernova

The

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 ...

SN 2012ht (

type Ia A Type Ia supernova (read: "type one-A") is a type of supernova that occurs in binary systems (two stars orbiting one another) in which one of the stars is a white dwarf. The other star can be anything from a giant star to an even smaller white ...

, mag. 18.6) was discovered in NGC 3447 by Koichi Nishiyama and Fujio Kabashima on December 18, 2012.

NGC 3447 group

NGC 3447 is the largest galaxy in a

group of galaxies 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 galaxies ...

named after it. The NGC 3447 group includes at least 4 other galaxies: NGC 3447A, NGC 3457, UGC 6022 and UGC 6035.

External links

NGC 3447
at NASA/IPAC
NGC 3447
at

SIMBAD SIMBAD (the Set of Identifications, Measurements and Bibliography for Astronomical Data) is an astronomy, astronomical database of objects beyond the Solar System. It is maintained by the Centre de données astronomiques de Strasbourg (CDS), Fr ...

NGC 3447
at LEDA
NGC 3447
at

SEDS Students for the Exploration and Development of Space (SEDS) is a non-profit international student organization whose purpose is to drive space advocacy of space exploration and development through educational and engineering projects. Hist ...

NGC 3447
(

DSS2 Digital Subscriber Signalling System No. 2 (DSS2), as the successor to DSS1, is also a digital Digital usually refers to something using discrete digits, often binary digits. Businesses *Digital bank, a form of financial institution *Digit ...

) at

WikiSky Sky-Map.org (or WikiSky.org) is a wiki and interactive sky map that covers over half a billion known celestial bodies. WikiSky is designed, in part, as a wiki. Users can edit information about different stars by writing articles, adding Internet ...

NGC 3447
( SDSS) at WikiSky
NGC 3447
(

GALEX Galaxy Evolution Explorer (GALEX or Explorer 83 or SMEX-7) was a NASA orbiting space telescope designed to observe the universe in ultraviolet wavelengths to measure the history of star formation in the universe. In addition to paving the way ...

) at WikiSky
NGC 3447
at Seligman

References

{{Leo (constellation) Magellanic spiral galaxies Barred spiral galaxies Interacting galaxies Discoveries by John Herschel Astronomical objects discovered in 1836 3447 06006 32694 IRAS catalogue objects Leo (constellation)

NGC 3447A

Supernova

NGC 3447 group

See also

External links

References