Celestial hemisphere:  Northern  ·  Constellation: Cassiopeia (Cas)  ·  Contains:  NGC 185
Getting plate-solving status, please wait...
NGC 185 Central Active Galactic Nucleus (AGN), Jerry Yesavage
NGC 185 Central Active Galactic Nucleus (AGN), Jerry Yesavage

NGC 185 Central Active Galactic Nucleus (AGN)

Getting plate-solving status, please wait...
NGC 185 Central Active Galactic Nucleus (AGN), Jerry Yesavage
NGC 185 Central Active Galactic Nucleus (AGN), Jerry Yesavage

NGC 185 Central Active Galactic Nucleus (AGN)

Equipment

Loading...

Acquisition details

Loading...

Description

I was interested in the central structure here that I had seen in other images and as it is very bright central structure I had hopes of isolating it in my murky skys.  Turns out the structure is something unusual and indeed is very bright, an Active Galactic Nucleus (AGN).

From Wikipedia: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 the luminosity is not produced by stars. Such excess, non-stellar emissions have been observed in the [url=mw-redirect=https://en.wikipedia.org/wiki/Radio_waves]radio[/url], microwave, infrared, optical, [url=mw-redirect=https://en.wikipedia.org/wiki/Ultra-violet]ultra-violet[/url], X-ray and gamma ray wavebands. A galaxy hosting an AGN is called an active galaxy. The non-stellar radiation from an AGN is theorized to result from the accretion of matter by a supermassive black hole at the center of its host galaxy.Active galactic nuclei are the most luminous persistent sources of electromagnetic radiation in the universe and, as such, can be used as a means of discovering distant objects; their evolution as a function of cosmic time also puts constraints on models of the cosmos.The observed characteristics of an AGN depend on several properties such as the mass of the central black hole, the rate of gas accretion onto the black hole, the orientation of the accretion disk, the degree of obscuration of the nucleus by dust, and presence or absence of jets.Numerous subclasses of AGN have been defined on the basis of their observed characteristics; the most powerful AGN are classified as quasars. A blazar is an AGN with a jet pointed toward the Earth, in which radiation from the jet is enhanced by relativistic beaming.

NGC 185 (also known as Caldwell 18) is a dwarf spheroidal galaxy located [url=mw-redirect=https://en.wikipedia.org/wiki/1_E19_m]2.08 million[/url] light-years from Earth, appearing in the constellationCassiopeia. It is a member of the Local Group, and is a satellite of the Andromeda Galaxy (M31).=reference[6] NGC 185 was discovered by William Herschel on November 30, 1787, and he cataloged it "H II.707".=reference[6]John Herschel observed the object again in 1833 when he cataloged it as "h 35", and then in 1864 when he cataloged it as "GC 90" within his [url=mw-redirect=https://en.wikipedia.org/wiki/General_Catalogue_of_Nebulae_and_Clusters]General Catalogue of Nebulae and Clusters[/url].=reference[6] NGC 185 was first photographed between 1898 and 1900 by James Edward Keeler with the [url=mw-redirect=https://en.wikipedia.org/wiki/Crossley_Reflector]Crossley Reflector[/url] of Lick Observatory.=reference[6]

Unlike most dwarf elliptical galaxies, NGC 185 contains young [url=mw-redirect=https://en.wikipedia.org/wiki/Stellar_clusters]stellar clusters[/url], and star formation proceeded at a low rate until the recent past. NGC 185 has an active galactic nucleus (AGN) and is usually classified as a type 2 Seyfert galaxy,=reference[7] though its status as a Seyfert is questioned.=reference[8] It is possibly the closest Seyfert galaxy to Earth, and is the only known Seyfert in the Local Group.

Comments

Revisions

  • Final
    NGC 185 Central Active Galactic Nucleus (AGN), Jerry Yesavage
    Original
  • NGC 185 Central Active Galactic Nucleus (AGN), Jerry Yesavage
    B

Sky plot

Sky plot

Histogram

NGC 185 Central Active Galactic Nucleus (AGN), Jerry Yesavage