Hickson 74

Lore & Background

NGC 5910, the central elliptical galaxy of Hickson Compact Group 74, was discovered by astronomer William Herschel on April 13, 1785. It is a strong radio source with a conspicuous nuclear jet. The galaxy appears to have a double nucleus, with a faint nuclear dust lane also observed. A pair of asymmetries in the isophotal profile of NGC 5910—one brighter than the other, weaker asymmetry—suggests a past merger and collision of one or more galaxies.

The group consists of five members in total: NGC 5910, 2MASX J15193179+2053005, PGC 54692, PGC 54694, and MCG+04-36-036. The other galaxies appear to be embedded within a common envelope that belongs to NGC 5910. NGC 5910 lies near the Hercules Superclusters.

Reader's Guide

Hickson Compact Group 74 is significant as a compact galaxy group whose brightest member, NGC 5910, exhibits evidence of a past merger through its double nucleus and asymmetrical isophotal profile. The group's five members are bound within a velocity dispersion of 537 km/s and span a diameter of 260,000 light-years. The fact that the other galaxies appear embedded in a common envelope belonging to NGC 5910 suggests ongoing or recent dynamical interaction. Two type Ia supernovae have been discovered in NGC 5910: SN 2002ec, found in July 2002 via unfiltered KAIT CCD images by Li and Beutler, and PSN J15192497+2054024, discovered on 17 March 2013 by the Catalina Real-Time Transient Survey and Stan Howerton. These supernovae provide additional data on stellar evolution within the group. The group's proximity to the Hercules Superclusters places it in a larger cosmic structure, though the article does not specify a direct physical association.

Did You Know?

• NGC 5910, the brightest member of Hickson 74, is a strong radio source with a conspicuous nuclear jet.
• The group has a velocity dispersion of 537 km/s and a diameter of 260,000 light-years.
• The other galaxies in the group appear embedded within a common envelope belonging to NGC 5910.