NGC 4457
NGC 4457 is an intermediate spiral galaxy located about 55 million light-years away[2] in the constellation of Virgo.[3] It is also classified as a LINER galaxy, a class of active galaxy defined by their spectral line emissions.[4][2] NGC 4457 Is inclined by about 33°.[5] It was discovered by astronomer William Herschel on February 23, 1784.[6] Despite being listed in the Virgo Cluster Catalog as VCC 1145,[7] NGC 4457 is a member of the Virgo II Groups[8][9][10] which form an extension of the Virgo cluster.[8][11] NGC 4457 may have had a recent minor merger with another galaxy.[12] SupernovaOn July 1 2020, an astronomical transient was discovered in NGC 4457 by astronomer Kōichi Itagaki and confirmed by ASAS-SN. Spectroscopic classification determined the object to be a type Ia Supernova, designated SN 2020nvb.[13] Physical characteristicsNGC 4457 has a broad oval zone containing an inner spiral which is defined mainly by two fairly open arms. There is a well-defined outer ring that is completely detached from the inner regions of the galaxy.[14] Truncated diskNGC 4457 has a severely reduced amount of star-formation in its disk while its inner regions have a normalized rate of massive star formation.[14] This may have been caused by a recent interaction of the gas in the galaxy with the gas in the surrounding Virgo Cluster,[15] causing the gas to be stripped away in an effect known as ram-pressure stripping.[16] See also
References
External linksWikimedia Commons has media related to NGC 4457.
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