Science: Dim Pleiad

Alcyone, Asterope, Electra, Kelaine, Maia, Merope and Taygete were the seven daughters of Atlas and Pleïone. According to one Greek myth, the seven sisters were pursued so ardently by Hunter Orion that Zeus changed them into a constellation of stars, the Pleiades. One of the seven is dim because of mourning for a sister who married a mortal.

The bright group of the Pleiades, near the celestial figure of amorous Orion, has been a source of wonder and speculation to shepherds and seers since the dawn of history. Telescopes reveal thousands of stars in the cluster, moving away from Earth at six miles per second (present distance: nearly two quadrillion miles). To Babylonians the naked eye stars were ”The Many Little Ones,” to American Indians “The Seven Brothers.” In some folklore they are called “The Seven Who Now Are Six.” as though an ancient memory persisted that the dim star, which can be seen only by keen eyes on clear nights, was once a match for its sisters.

That the seventh Pleiad is indeed a variable star was reported last week by Harvard Observatory. The cluster is draped in a veil of diffuse nebulosity which may vary the brightness of certain stars by interposing streamers of varying thicknesses. Observations by Dr. William Alexander Calder disclosed that in a year the seventh Pleiad, now called Pleïone, had diminished by one-sixth of a magnitude in brightness. It cannot have been decreasing for very long at this rate, otherwise it would have been the brightest star in the sky less than a half century ago. But the fact of its variability does support the legend that Pleïone was once a conspicuous member of the Seven Sisters.