NGC 3198
galaxy
NGC 3198, also known as Herschel 146 is a barred spiral galaxy in the constellation Ursa Major. It was discovered by German-British astronomer William Herschel on 15 January 1788. NGC 3198 is located in the Leo Spur, which is part of the Virgo Supercluster, and is approximately 47 million light years away.
NGC 3198 was one of 18 galaxies targeted by the Hubble Space Telescope (HST) Key Project on the Extragalactic Distance Scale, which aimed to calibrate various secondary distance indicators and determine the Hubble constant to an accuracy of 10%. The type and orientation of NGC 3198 made it suitable for these measurements. The Wide Field and Planetary Camera 2 (WFPC2) of the HST was used to measure the magnitudes of 52 Cepheid variables, and the resulting distance modulus corresponded to a distance of 14.5 Mpc (47 million light years).
Observations made with the Westerbork Synthesis Radio Telescope detected for the first time the presence of extraplanar gas. The extraplanar gas makes up approximately 15% of the total atomic hydrogen (HI) mass of the galaxy.
Supernovae
Two supernovae have been observed in NGC 3198:
SN 1966J (Type Ia, mag. 13) was discovered by Paul Wild on 18 December 1966.
This brief starts where responsible research should: with the source description of “NGC 3198” as galaxy. Everything that follows is an evidence route, not borrowed authority.
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Vocabulary and entity names are the principal evidence signals here, because they determine the precision of every later search. The source revision retrieved here is dated Sep 3, 2026. The linked authority identifier is Q1103488. None of the 0 selected statements returned an explicit reference. The first chronological checks are 1788 and 1966.
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This entry incorporates text from “NGC 3198” on English Wikipedia. Contributors are listed in the page history. Text is available under the Creative Commons Attribution-ShareAlike 4.0 License. Selected authority identifiers and statements are retrieved from Wikidata under CC0; their references and qualifiers remain part of the verification path.