Shapley Constellations

A low magnification cruise around the Cloud’s five Shapley constellations is a journey of both mind and imagination

The Cloud’s five constellations

In 1931 Harlow Shapley noted 15 “small irregular star clouds” and that “nearly all of them appear to be distinct physical organisations.” In 1951 he noted that many of them have 10 times the diameters and luminosities of M11 and the Pleiades and he asked, “Should such widespread assemblies be called subclouds or subclusters or would it be better to designate them constellations? They are doubtless comparable to the Orion, Scorpius and Vela aggregations of bright galactic stars.”

In 1953 Virginia McKibben Nail and Harlow Shapley published their paper, Magellanic Clouds VII. Star colors and luminosities in five constellations, in which they wrote, “We have examined five stellar aggregations in the Large Magellanic Cloud that average something more than one thousand light years in diameter. We call them constellations because of their rough similarity in size, population, and star colors to the Orion constellation and similar stellar associations in our galactic system. The luminosities of the blue member stars range from -8 to -5 in absolute photographic magnitude. A few exceedingly red supergiant stars also appear in these constellations, as well as a large number of blue stars fainter than M = -5, as in the Orion, Perseus, and Scorpius-Centaurus groups.” Thus, the Large Magellanic Cloud acquired its constellations.

Constellation V lies in the bar of the Cloud, and the others are on the north side. Although the areas in each constellation are square – varying from 17′ x 17′ to 33′ x 33′ – the constellations are all elongated or irregular in outline.

Shapley’s five constellations. The photo was taken by astronomer and astronaut Karl Henize in Bloemfontein, South Africa, in 1951

Please note:

The NGC number identifies the position of the constellation.

The measured areas that Shapley and Nail identified in each region as constellations are square, but they actually are all elongated or irregular in outline.

Constellation I

NGC 1935

RA: 05 21 58.0 Dec: -67 57

Size: 26′ x 26′

Location: Superbubble N44