The galaxy NGC 4424 has a peculiar morphology with shells that give the appearance of a galaxy merger within the last half billion years. It has a long tail of hydrogen stretching 110 kpc to the south that is likely due to stripping from ram pressure. Because of the lack of gas, star formation has completely ceased in the outer parts of the galaxy, while there is still a mild amount occurring in the inner region. NGC 4424 will most likely end up as a lenticular galaxy by three billion years from now.[5]
There is no indication of a compact source of X-ray emission in the nucleus, but there is an ionized tail stretching ~10 kpc from the core.[5] The velocity dispersion at the core suggests there is a supermassive black hole (SMBH) with a mass of (0.8±0.2)×105M☉.[9]Hubble images of this galaxy show a tidally-stretchedcluster located at a projected distance of ~400 pc from the nucleus. This is probably the core of a captured galaxy. It contains a compact source that is emitting X-rays and may be an active massive black hole. In time this may merge with the core SMBH of NGC 4424.[9]
Max Wolf discovered SN 1895A (type unknown, mag. 12.5) on March 16, 1895.[10]
Type Ia supernova designated SN 2012cg was discovered in this galaxy by the LOSS program from images taken May 17, 2012.[11] It reached maximum light nine days later at the end of May,[12] and was the brightest supernova of the year 2012.[13] The supernova reached a peak absolute magnitude of −19.50±0.31 in the B (blue) band and synthesized 0.72±0.31 M☉ of the radioactiveisotopenickel-56.[2] The available observations favor a merger of double degenerate progenitors as the source for the event.[14] The proximity of the galaxy made this one of the best studied supernova explosions to date.[14]
^Kandrashoff, M.; et al. (May 2012). Green, D. W. E. (ed.). "Supernova 2012cg in NGC 4424 = Psn J12271283+0925132". Central Bureau Electronic Telegrams. 3111 (1): 1. Bibcode:2012CBET.3111....1K.
