Most rich clusters of galaxies have their share of peculiar galaxies. The same can be said about distorted halos, strange dust lanes, and tails and plumes in seemingly-non-interacting galaxies. For instance, astronomers can’t yet explain why some galaxies seem to be exploding. The exploding M82 with its knotty structure is probably the most famous peculiar galaxy.Įxcept for the case of galaxies which are obviously involved in a gravitational interaction, the causes of most galactic peculiarities are quite mysterious. M101 has very asymmetric arms, as does M106. M64 has an out-of-place dark patch giving it its title of the “Black-eye Galaxy.” M66 is a barred spiral with somewhat asymmetric arms, and M77 is a Seyfert-type galaxy with a brilliant nucleus which seems to be exploding. M51’s companion, NGC 5195, is a very dusty peculiar galaxy. M49 is not generally listed as being peculiar in any way, but it does have a very faint bridge linking it with a tiny irregular galaxy estimated to be about 17th magnitude. And even though all peculiar galaxies are relatively rare, there are quite a few in the Messier catalog. Some of these - like the last - are extremely rare, but examples of each sort have been observed. possible interactions with intergalactic clouds of dust or gas.particularly distorted interactions with other galaxies.There are a number of things which can give galaxies the distinction of being peculiar - such as: Of course, galaxies that have peculiarities are more common - such as M87, the supergiant elliptical whose famous jet gives it a “p” for “peculiar” in its classification: E0p. Irregular galaxies make up only three to four percent of known galaxies, and the peculiar galaxies come in at less than one percent. Although dwarf spheroidal galaxies - like the Sculptor and Fornax Dwarfs - are the most common in the universe as a whole, they are not observable beyond the Local Group. Spiral galaxies appear to be the most numerous readily observable type of galaxy, with the ellipticals coming in a rather distant second. Most telescopic observers have examined at least a few galaxies, and those with larger apertures have probably ventured beyond the confines of the Messier list to observe some of the thousands of galaxies listed in the New General Catalogue (see “Observing Galaxies” in Astronomy, April 1980).īut if you find yourself itching for still more cosmic exploration, why not search out a few of the more unusual denizens of our universe: the peculiar galaxies? It has been said that all galaxies are peculiar to some extent, but here we are talking about the truly strange or distorted galaxies - those officially classified as “peculiar.” What makes a galaxy peculiar? You know that the diffuse glow in your eyepiece comes from the combined light of billions of stars organized in a vast cosmic system so distant that its gleam takes millions of years to reach your telescope. Observing a galaxy is always an exciting experience. So, here, we present the original text, alongside photos taken with more modern equipment. Though technology has changed massively, the thrill of visual observations of peculiar galaxies remains. The author revisits the topic in this year’s September issue, available now. This story ran in the February 1981 issue of Astronomy in the Gazer’s Gazette section as Alan Goldstein’s first contribution to the magazine.
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