NGC 3489 is a lenticular galaxy located in the constellation

Leo Leo or Léo may refer to: Acronyms * Law enforcement officer * Law enforcement organisation * ''Louisville Eccentric Observer'', a free weekly newspaper in Louisville, Kentucky * Michigan Department of Labor and Economic Opportunity Arts an ...

. It is located at a distance of about 30 million

light year A light-year, alternatively spelled light year, is a large unit of length used to express astronomical distances and is equivalent to about 9.46 trillion kilometers (), or 5.88 trillion miles ().One trillion here is taken to be 1012 ...

s from Earth, which, given its apparent dimensions, means that NGC 3489 is about 30,000 light years across. It was discovered by William Herschel on April 8, 1784. NGC 3489 is a member of the

Leo Group The M96 Group (also known as the Leo I Group) is a group of galaxies in the constellation Leo. This group contains between 8 and 24 galaxies, including three Messier objects. It also contains the Leo Ring. The group is one of many groups t ...

. NGC 3489 has a weak

bar Bar or BAR may refer to: Food and drink * Bar (establishment), selling alcoholic beverages * Candy bar * Chocolate bar Science and technology * Bar (river morphology), a deposit of sediment * Bar (tropical cyclone), a layer of cloud * Bar (u ...

, seen along the minor axis, and a small bulge. The age of the stellar population in NGC 3489 shows a gradient, with the younger stars lying closer to the core. When observed in H-beta, the central arcsecond of NGC 3489 shows a peak, indicating the presence of younger stars at the core, whose age is estimated to be about 1.7 Gys. Although currently NGC 3489 is considered a post- starburst galaxy, there is still molecular gas in the nucleus that can lead to

star formation Star formation is the process by which dense regions within molecular clouds in The "medium" is present further soon.-->interstellar space

, although its mass is less than what is found in galaxies with active star formation. In the nuclear region of NGC 3489 has been observed dust with an open spiral pattern. The galaxy has an outer ring structure, with a diameter of 1.54 arcminutes along the major axis. NGC 3489 has an active galactic nucleus, which has been categorised based on its spectrum as a type 2 Seyfert galaxy or, based on the nuclear Iemission strength, which lies between that of H II nuclei and

LINER A low-ionization nuclear emission-line region (LINER) is a type of galactic nucleus that is defined by its spectral line emission. The spectra typically include line emission from weakly ionized or neutral atoms, such as O, O+, N+, and S+. ...

, a transition object. This kind of transition emission could be attributed to post AGB stars located in the core. A supermassive black hole which accretes material in the centre of the galaxy is believed to be the cause of nuclear activity. In the centre of NGC 3489 lies a black hole with estimated mass based on velocity dispersion.

Gallery

NGC3489 - SDSS DR14.jpg, NGC 3489 (SDSS DR14) NGC3489-hst-R814GB658.jpg , NGC 3489 imaged by the Hubble Space Telescope

References

External links

NGC 3489 on SIMBAD
{{Ngc35 Lenticular galaxies Leo (constellation) category:M96 Group 3489 6082 33160 Astronomical objects discovered in 1784 Discoveries by William Herschel