NGC 925 is a

barred spiral galaxy A barred spiral galaxy is a spiral galaxy with a central bar-shaped structure composed of stars. Bars are found in about two thirds of all spiral galaxies in the local universe, and generally affect both the motions of stars and interstellar gas ...

located about 30 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

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 ...

German-British There are many Germans living in the United Kingdom, and many Britons or ''German British'' () have German ancestry, including the British royal family. While those born in Germany constitute one of the UK's largest Foreign-born population of the ...

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 ...

discovered this galaxy on 13 September 1784. The morphological classification of this galaxy is SB(s)d, indicating that it has a bar structure and loosely wound spiral arms with no ring. The spiral arm to the south is stronger than the northern arm, with the latter appearing

flocculent In colloidal chemistry, flocculation is a process by which colloidal particles come out of suspension to sediment in the form of floc or flake, either spontaneously or due to the addition of a clarifying agent. The action differs from precipita ...

and less coherent. The bar is offset from the center of the galaxy and is the site of star formation all along its length. Both of these morphological traits—a dominant spiral arm and the offset bar—are typically characteristics of a

Magellanic spiral A Magellanic spiral galaxy is a spiral galaxy with only one spiral arm. Magellanic spiral galaxies are classified as the type Sm (with sub-categories SAm, SBm, SABm); the prototype galaxy and namesake for Magellanic spirals is the Large Magell ...

galaxy. The galaxy is inclined at an angle of 55° to the line of sight along 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 102°. The NGC 925 is a member of the

NGC 1023 Group The NGC 1023 Group is a group of galaxies about away from Earth. It is a group in the Local Supercluster, along with the Local Group. Members * Probable (dwarfs): DDO 024, DDO 025. * Possible members: NGC 672, IC 1727, NGC 1156(?). * Possibl ...

, a nearby, gravitationally-bound

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 ...

associated with NGC 1023. However, the nearest member lies at least distant from NGC 925. There is a 10 million

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 ...

() cloud of

neutral hydrogen The hydrogen line, 21 centimeter line, or H I line is a spectral line that is created by a change in the energy state of solitary, electrically neutral hydrogen atoms. It is produced by a spin-flip transition, which means the directio ...

attached to NGC 925 by a streamer. It is uncertain whether this is a satellite

dwarf galaxy A dwarf galaxy is a small galaxy composed of about 1000 up to several billion stars, as compared to the Milky Way's 200–400 billion stars. The Large Magellanic Cloud, which closely orbits the Milky Way and contains over 30 billion stars, is so ...

, the remnant of a past tidal interaction, or a cloud of primordial gas. Although no

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 ...

e have been observed in NGC 925 yet, a

luminous red nova A luminous red nova (abbr. ''LRN'', pl. ''luminous red novae'', pl.abbr. ''LRNe'') is a stellar explosion thought to be caused by the merging of two stars. They are characterised by a distinct red colour, and a light curve that fades slowly with ...

, designated AT 2023nzt (type LRN, mag. 19), was discovered on 26 July 2023.Transient Name Server entry for AT 2023nzt.
Retrieved 25 October 2023.

References

External links

* {{DEFAULTSORT:NGC 0925 Barred spiral galaxies Triangulum 0925 01913 009332 NGC 1023 Group Astronomical objects discovered in 1784 Galaxies discovered in 1784 Discoveries by William Herschel