Hickson 40
Galaxy cluster in the constellation Hydra
Hickson 40 is a well-known galaxy group in the constellation Hydra. It consists of 5 separate members (three spiral galaxies, an elliptical galaxy, and a lenticular galaxy) and is in the stage of merging. Member galaxies of Hickson 40 interacted in the early stages of their formation to create a crowded galaxy sampler. Hickson 40 resides at a distance of 300 million light years and is so dense that it could even exist within a region close to the diameter of the Milky Way's galactic disk.
01Location
Although Hickson 40 is remarkably self-sustained, the vast majority of galaxy clusters that resemble it are typically a part of larger galaxy cluster. It can be located in the Hydra constellation.
02Formation
Researchers have observed Hickson 40 in many wavelengths, including visible light, radio, infrared, and X-ray. Majority of the galaxies within the cluster have a dense radio source in the cores, which could be proof for the existence of supermassive black holes. X-ray surveys have revealed that the galaxies are pushing closer together because of the amount of hot gas present. Infrared observations reveal fast rates of star formation. Hickson 40 is one of the most compact galaxy clusters ever observed, making it a valuable research point NASA. Research shows that galaxy cluster were more prevalent in the early universe, and helped the formation of quasars, whose luminosity from heated infalling material spread across the universe. Studying the formation of galaxies in other close groups like Hickson 40 have given astronomers a chance to sort out when and where galaxies assemble themselves, and what material they are made of.
03Supernovae
Two supernovae have been observed in HCG 40.
- SN 2003D (Type Ia, mag. 17.5) was discovered by Tim Puckett and Alex Langoussis on 6 January 2003. It was located 1".6 east and 10".2 south of the nucleus of MCG -1-25-8.
- SN 2026dwm (Type IIb, mag. 19.97) was discovered by GOTO on 21 February 2026.
Sources and credits
This article is adapted from the Wikipedia article “Hickson 40”, written by its contributors and licensed under CC BY-SA 4.0. Fathomly has changed the layout, removed citation markers, navigation and maintenance notices, and adjusted punctuation. This adapted version is shared under the same license. For references, see the original article.
Images, from Wikimedia Commons:
- ARP321 - HST - Hickson Compact Group 40.jpg by Judy Schmidt, CC BY 2.0
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