__NOTOC__ Messier 96 (also known as M96 or NGC 3368) is an

intermediate spiral galaxy An intermediate spiral galaxy is a galaxy that is in between the classifications of a barred spiral galaxy and an unbarred spiral galaxy. It is designated as SAB in the galaxy morphological classification system devised by Gerard de Vaucouleur ...

about 31 million

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 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 ...

Leo Leo is the Latin word for lion. It most often refers to: * Leo (constellation), a constellation of stars in the night sky * Leo (astrology), an astrological sign of the zodiac * Leo (given name), a given name in several languages, usually mas ...

Observational history and appearance

It was discovered by French astronomer

Pierre Méchain Pierre François André Méchain (; 16 August 1744 – 20 September 1804) was a French astronomer and surveyor who, with Charles Messier, was a major contributor to the early study of deep-sky objects and comets. Life Pierre Méchain was bo ...

in 1781. After communicating his finding, French astronomer

Charles Messier Charles Messier (; 26 June 1730 – 12 April 1817) was a French astronomer. He published an astronomical catalogue consisting of 110 nebulae and star clusters, which came to be known as the ''Messier objects'', referred to with th ...

confirmed the finding four days later and added it to his catalogue of nebulous objects. Finding this object is burdensome with large binoculars. Ideal minimum resolution, in a good sky, is via a telescope of

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 ...

, to reveal its halo with a brighter core region. This complex galaxy is inclined by an angle of about 53° to the line of sight from the

Earth Earth is the third planet from the Sun and the only astronomical object known to Planetary habitability, harbor life. This is enabled by Earth being an ocean world, the only one in the Solar System sustaining liquid surface water. Almost all ...

, which is oriented at 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 172°.

Properties

It is categorized as a double-barred spiral galaxy with a small inner bulge through the core along with an outer bulge. The nucleus displays a weak level of activity of the

LINER Liner or LINER may refer to: Line drawing * Eye liner, a type of makeup * Marker pen, a porous-tip pen with its own ink source * Multiple lining tool used in engraving * A sable brush used by coach painters Linings * Acoustic liner, a no ...

2 type. Variations in

ultraviolet Ultraviolet radiation, also known as simply UV, is electromagnetic radiation of wavelengths of 10–400 nanometers, shorter than that of visible light, but longer than X-rays. UV radiation is present in sunlight and constitutes about 10% of ...

emission from the core suggest the presence of a

supermassive black hole A supermassive black hole (SMBH or sometimes SBH) is the largest type of black hole, with its mass being on the order of hundreds of thousands, or millions to billions, of times the mass of the Sun (). Black holes are a class of astronomical ...

. Estimates for the mass of this object range from to

solar mass The solar mass () is a frequently used unit of mass in astronomy, equal to approximately . It is approximately equal to the mass of the Sun. It is often used to indicate the masses of other stars, as well as stellar clusters, nebulae, galaxie ...

es (). On May 9, 1998 a

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 ...

was discovered in this galaxy by Mirko Villi. Designated SN 1998bu, this was a

Type Ia supernova 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 ...

explosion. It reached maximum brightness on May 21 at about magnitude 11.6, then steadily faded.Images of Supernova 1998bu in M96.
Retrieved 26 March 2023. Observations of the ejecta a year later showed creation of 0.4 solar masses of iron. The

spectrum A spectrum (: spectra or spectrums) is a set of related ideas, objects, or properties whose features overlap such that they blend to form a continuum. The word ''spectrum'' was first used scientifically in optics to describe the rainbow of co ...

of the

supernova remnant A supernova remnant (SNR) is the structure resulting from the explosion of a star in a supernova. The supernova remnant is bounded by an expanding shock wave, and consists of ejected material expanding from the explosion, and the interstellar mat ...

confirmed too radioactive ⁵⁶Co, which decays into ⁵⁶Fe. Messier 96 is about the same mass and size as the

Milky Way The Milky Way or Milky Way Galaxy is the galaxy that includes the Solar System, with the name describing the #Appearance, galaxy's appearance from Earth: a hazy band of light seen in the night sky formed from stars in other arms of the galax ...

. It is a very asymmetric galaxy; its dust and gas are unevenly spread throughout its weak spiral arms, and its core is just offset from the midpoint of its extremes. Its arms are also asymmetrical, thought to have been influenced by the gravitational pull of other galaxies within its group. Messier 96 is being studied as part of a survey of 50 nearby galaxies known as the Legacy ExtraGalactic UV Survey (LEGUS), providing an unprecedented view of star formation within the local universe.

M96 group

M96 is the brightest galaxy within the M96 Group, 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 ...

, the other

Messier objects The Messier objects are a set of 110 astronomical objects catalogued by the French astronomer Charles Messier in his ' (''Catalogue of Nebulae and Star Clusters''). Because Messier was interested only in finding comets, he created a list of thos ...

of which are M95 and M105. To this are added at least nine other galaxies. This is the nearest group to the

Local Group The Local Group is the galaxy group that includes the Milky Way, where Earth is located. It has a total diameter of roughly , and a total mass of the order of . It consists of two collections of galaxies in a " dumbbell" shape; the Milky Way ...

to combine bright spirals and a bright elliptical galaxy (Messier 105).

References

External links

*
NOAO: M96

* {{Ngc35 Intermediate spiral galaxies Messier 096 Messier 096 096 Messier 096 05882 32192 17810320 Discoveries by Pierre Méchain

Observational history and appearance

Properties

M96 group

See also

References

External links