Explanation: NGC 4650A appears to be two galaxies in one. A rare type of galaxy known as a Polar Ring, NGC 4650A is composed of an old central group of stars and a young ring of stars rotating farther out. Both components are clearly visible in this featured photograph by the Hubble Space Telescope. What creates Polar Ring Galaxies is still being researched, but a leading theory is the collision of two distinct galaxies in the distant past. Polar Ring Galaxies allow astronomers to estimate the amount of dark matter in galaxies by measuring the rotation rate of the highly extended ring. An unknown type of dark matter is implied because the ring typically rotates too fast to be held together by only the visible stars.
1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024 |
Январь Февраль Март Апрель Май Июнь Июль Август Сентябрь Октябрь Ноябрь Декабрь |
NASA Web Site Statements, Warnings, and Disclaimers
NASA Official: Jay Norris. Specific rights apply.
A service of: LHEA at NASA / GSFC
& Michigan Tech. U.
Публикации с ключевыми словами:
ring galaxy - polar ring - dark matter - ring - темная материя - гало Галактики
Публикации со словами: ring galaxy - polar ring - dark matter - ring - темная материя - гало Галактики | |
См. также:
Все публикации на ту же тему >> |