NGC 3489 is alenticular galaxy located in the constellationLeo. It is located at a distance of about 30 millionlight years from Earth, which, given its apparent dimensions, means that NGC 3489 is about 30,000 light years across. It was discovered byWilliam Herschel on April 8, 1784.[3] NGC 3489 is a member of theLeo Group.[4]
NGC 3489 has a weakbar, seen along the minor axis, and a small bulge.[5] The age of the stellar population in NGC 3489 shows a gradient, with the younger stars lying closer to the core. When observed inH-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.[6] Although currently NGC 3489 is considered a post-starburst galaxy, there is stillmolecular gas in the nucleus that can lead tostar formation, although its mass is less than what is found in galaxies with active star formation.[7] In the nuclear region of NGC 3489 has been observed dust with an open spiral pattern.[6] The galaxy has an outer ring structure, with a diameter of 1.54 arcminutes along the major axis.[8]
NGC 3489 has anactive galactic nucleus, which has been categorised based on its spectrum as atype 2 Seyfert galaxy or, based on the nuclear [O I] emission strength, which lies between that of H II nuclei andLINER, a transition object.[9] This kind of transition emission could be attributed topost AGB stars located in the core.[7] Asupermassive 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(6±0.54)×106M☉ based onvelocity dispersion.[5]
^Seligman, Courtney."NGC 3489".Celestial Atlas. Retrieved19 November 2018.
^Stierwalt, Sabrina; Haynes, Martha P.; Giovanelli, Riccardo; Kent, Brian R.; Martin, Ann M.;Saintonge, Amélie; Karachentsev, Igor D.; Karachentseva, Valentina E. (1 August 2009). "The Arecibo Legacy Fast Alfa Survey. IX. The Leo Region H I Catalog, Group Membership, and the H I Mass Function for the Leo I Group".The Astronomical Journal.138 (2):338–361.arXiv:0906.2178.Bibcode:2009AJ....138..338S.doi:10.1088/0004-6256/138/2/338.S2CID15537435.
^Comerón, S.; Salo, H.; Laurikainen, E.; Knapen, J. H.; Buta, R. J.; Herrera-Endoqui, M.; Laine, J.; Holwerda, B. W.; Sheth, K.; Regan, M. W.; Hinz, J. L.; Muñoz-Mateos, J. C.; Gil de Paz, A.; Menéndez-Delmestre, K.; Seibert, M.; Mizusawa, T.; Kim, T.; Erroz-Ferrer, S.; Gadotti, D. A.;Athanassoula, E.; Bosma, A.; Ho, L. C. (19 February 2014). "ARRAKIS: atlas of resonance rings as known in the S4G".Astronomy & Astrophysics.562: A121.arXiv:1312.0866.Bibcode:2014A&A...562A.121C.doi:10.1051/0004-6361/201321633.S2CID119295831.
^Ho, Luis C.; Filippenko, Alexei V.; Sargent, Wallace L. W. (October 1997). "A Search forDwarf Seyfert Nuclei. III. Spectroscopic Parameters and Properties of the Host Galaxies".The Astrophysical Journal Supplement Series.112 (2):315–390.arXiv:astro-ph/9704107.Bibcode:1997ApJS..112..315H.doi:10.1086/313041.S2CID17086638.
