page_title: Messier 105
hierarchical_section_title: Messier 105
caption_attribution_description: English: The heart of the Lion The heart of the Lion It might appear featureless and unexciting at first glance, but NASA/ESA Hubble Space Telescope observations of this elliptical galaxy — known as Messier 105 — show that the stars near the galaxy’s centre are moving very rapidly. Astronomers have concluded that these stars are zooming around a supermassive black hole with an estimated mass of 200 million Suns! This black hole releases huge amounts of energy as it consumes matter falling into it and causing the centre to shine far brighter than its surroundings. This system is known as an active galactic nucleus. Hubble also surprised astronomers by revealing a few young stars and clusters in Messer 105, which was thought to be a “dead” galaxy incapable of star formation. Messier 105 is now thought to form roughly one Sun-like star every 10 000 years. Star-forming activity has also been spotted in a vast ring of hydrogen gas encircling both Messier 105 and its closest neighbour, the lenticular galaxy NGC 3384. Messier 105 was discovered in 1781, lies about 30 million light-years away in the constellation of Leo (The Lion), and is the brightest elliptical galaxy within the Leo I galaxy group. Credit: ESA/Hubble &amp; NASA, C. Sarazin et al. Coordinates Position (RA):	10 47 49.63 Position (Dec):	12° 34' 55.76" Field of view:	6.31 x 6.39 arcminutes Orientation:	North is 127.8° right of vertical Colours &amp; filters Band	Wavelength	Telescope Optical g	475 nm	Hubble Space Telescope ACS Optical z	850 nm	Hubble Space Telescope ACS Optical g	475 nm	Hubble Space Telescope ACS Optical Z	850 nm	Hubble Space Telescope ACS .
context_page_description: Messier 105 or M105, also known as NGC 3379, is an elliptical galaxy located 36.6 million light years away in the equatorial constellation of Leo. It was discovered by Pierre Méchain on 24 March 1781, just a few days after he discovered the nearby galaxies Messier 95 and Messier 96. This galaxy is one of several that were not originally included in the original Messier Catalogue compiled by Charles Messier. Messier 105 was included in the catalog only when Helen S. Hogg found a letter by Méchain describing Messier 105 and when the object described by Méchain was identified as a galaxy previously named NGC 3379.
  This galaxy has a morphological classification of E1, indicating a standard elliptical galaxy with a flattening of 10%. The major axis is aligned along a position angle of 71°. Isophotes of the galaxy are near perfect ellipses, twisting no more than 5° out of alignment, with changes in ellipticity of no more than 0.06. There is no fine structure apparent in the isophotes, such as ripples. Observation of giant stars in the halo indicate there are two general populations: a dominant metal-rich subpopulation and a weaker metal-poor group.
context_section_description: Messier 105 or M105, also known as NGC 3379, is an elliptical galaxy located 36.6 million light years away in the equatorial constellation of Leo. It was discovered by Pierre Méchain on 24 March 1781, just a few days after he discovered the nearby galaxies Messier 95 and Messier 96. This galaxy is one of several that were not originally included in the original Messier Catalogue compiled by Charles Messier. Messier 105 was included in the catalog only when Helen S. Hogg found a letter by Méchain describing Messier 105 and when the object described by Méchain was identified as a galaxy previously named NGC 3379.
  This galaxy has a morphological classification of E1, indicating a standard elliptical galaxy with a flattening of 10%. The major axis is aligned along a position angle of 71°. Isophotes of the galaxy are near perfect ellipses, twisting no more than 5° out of alignment, with changes in ellipticity of no more than 0.06. There is no fine structure apparent in the isophotes, such as ripples. Observation of giant stars in the halo indicate there are two general populations: a dominant metal-rich subpopulation and a weaker metal-poor group.
  Messier 105 is known to have a supermassive black hole at its core whose mass is estimated to be between 1.4×10⁸ and 2×10⁸ M☉. The galaxy has a weak active galactic nucleus of the LINER type with a spectral class of L2/T2, meaning no broad Hα line and intermediate emission line ratios between a LINER and a H II region. The galaxy also contains a few young stars and stellar clusters, suggesting some elliptical galaxies still form new stars, but very slowly.
  This galaxy, along with its companion the barred lenticular galaxy NGC 3384, is surrounded by an enormous ring of neutral hydrogen with a radius of 200 kiloparsecs (650 kilolight-years) and a mass of 1.8×10⁹ M☉ where star formation has been detected. Messier 105 is one of several galaxies within the M96 Group (also known as the Leo I Group), a group of galaxies in the constellation Leo. The group also includes the Messier objects M95 and M96.
caption: M105, as viewed by the HST;
  Credit: NASA/ESA
exif: {"Image ImageDescription": "It might appear featureless and unexciting at first glance, but NASA/ESA Hubble Space Telescope observations of this elliptical galaxy \u2014 known as Messier 105 \u2014 show that the stars near the galaxy\u2019s centre are moving very rapidly. Astronomers have concluded that these stars are zooming around a supermassive black hole with an estimated mass of 200 million Suns! This black hole releases huge amounts of energy as it consumes matter falling into it and causing the centre to shine far brighter than its surroundings. This system is known as an active galactic nucleus. Hubble also surprised astronomers by revealing a few young stars and clusters in Messer 105, which was thought to be a \u201cdead\u201d galaxy incapable of star formation. Messier 105 is now thought to form roughly one Sun-like star every 10 000 years. Star-forming activity has also been spotted in a vast ring of hydrogen gas encircling both Messier 105 and its closest neighbour, the lenticular galaxy NGC 3384. Messier 105 was discovered in 1781, lies about 30 million light-years away in the constellation of Leo (The Lion), and is the brightest elliptical galaxy within the Leo I galaxy group.", "Image Software": "Adobe Photoshop CC 2018 (Windows)", "Image DateTime": "2018:06:18 08:44:27"}