NGC 4631 (also known as the Whale Galaxy or Caldwell 32) is a barred spiral galaxy in the constellationCanes Venatici about 30 million light years away from Earth. It was discovered on 20 March 1787 by German-British astronomer William Herschel.[4] This galaxy's slightly distorted wedge shape gives it the appearance of a herring or a whale, hence its nickname.[3] Because this nearby galaxy is seen edge-on from Earth, professional astronomers observe this galaxy to better understand the gas and stars located outside the plane of the galaxy.
supernovae. So many supernovae have exploded in the center of NGC 4631 that they are blowing gas out of the plane of the galaxy. This superwind can be seen in X-rays[7] and in spectral line emission.[5] The gas from this superwind has produced a giant, diffuse corona of hot, X-ray emitting gas around the whole galaxy.[8]
Although no supernovae have been observed in NGC 4631 yet, a luminous red nova, designated AT2021biy, was discovered on 29 January 2021 (type LRN, mag. 18.1).[9]
NGC 4657.[11][12][13][14] However, exact group identification is problematic because this galaxy and others lie in a part of the sky that is relatively crowded. Estimates of the number of galaxies in this group range from 5[11] to 27,[14]
and all studies identify very different member galaxies for this group.
12h 42m 08s, +32° 32′ 29″
