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Leo Ring

Intergalactic cloud in Leo

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Proper NameLeo Ring
Messier NumberNone
NGC/IC NumberNone
Right Ascension10h 48m 19s
Declination+12° 41' 21"
Distancec.38,000,000 light years
c.11,700,000 parsecs
MagnitudeNot applicable
DiameterApparent: 1° 33'
Actual: 650,000 light years
Optimum VisibilityMarch

The name given to a vast ring of hydrogen and helium within the Leo I Group of galaxies, approximately thirty-eight million light years from the Milky Way. The ring is thought to have originated in the collision of two galaxies at the heart of the group, M105 and NGC 3384, more than a billion years ago. The galaxies themselves survived their dramatic interaction, but much of their interstellar gas was stripped away and cast into space, and has since been expanding outward to create the Leo Ring.

The Leo Ring is not detectable in visible light, and so cannot be seen directly in this image, but it fills most of the vertical height of the region shown. Near the marked centre are the two galaxies, M105 and NGC 3384, whose collision is thought to have created the ring. To the southwest is the barred spiral M96, which is connected to the main ring structure by a bridge of gases. Imagery provided by Aladin sky atlas

The ring takes the form of an elongated ellipse, somewhat broken on its northern edge, that has reached a diameter of some 650,000 light years (equivalent to about six times the diameter of the Milky Way). Its southern edge now approaches another galaxy within the group, M96, and the gases of the ring have distorted to form a band that extends outward towards that galaxy, giving the entire ring structure, seen in radio wavelengths, the appearance of an immense letter 'Q' in space. There are indications that local regions within the ring are in the process of collapsing to form new dwarf galaxies and, within these young galaxies, the ring's hydrogen and helium is condensing to form new generations of stars.


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