Andrew Cooper
Nov 13, 2020    Waikoloa, HI (map)
20cm f/6 Newtonian, Cave Astrola @ 136x
Seeing: 5 Transparency: 6 Moon: 0%

Brilliant blue-white, Pleione is 5' north, in the eastern margin of the Pleiades cluster

Captain William Henry Smyth
Dec 17, 1832    No. 6 The Crescent, Bedford, England (map)
150mm f/17.6 refractor by Tully 1827

A bright star with a distant companion, bringing up the rear of the Pleiades. A 5, intense white; B 9, pale blue. Here the principal star is Atlas, which is marked in Σ.'s Catalogue of 1827 "fortasse cuneus;" I was therefore induced to give it a rigid examination, at various times, under my fullest powers, but always made the disc perfectly round. On the arrival, therefore, of the grand Dorpat Catalogue, in 1837, I w as not at all surprised to find that in 1836.74, Σ. gazing at this star with a power of 800, records, "Stella simplex in optima nocte." Yet, as the same excellent astronomer had undoubtedly seen it double, with a visible line between the two individuals, it should be closely watched. These were his measures:

    Pos. 107°5  Dist. 0".79  Ep. 1827.16

Now as the motions of the heavenly bodies afford the most obvious instance of unlimited power, the object before us assumes the highest interest. From the conditions here stated, Atlas pursues its course with a rapid and restless activity in a circular orbital progression, performed in a plane nearly parallel to our line of vision. The revolution must consequently occupy a period so comparatively short, that imagination is confounded at its probable velocity.

A slight movement of Atlas in space is thus valued:

    P....  RA +0".02  Dec. +0".03
    B....     +0".05       -0".05
   [Hipparcos +0".01770    -0".04418]

Since the above was written, I find that Professor Struve, in examining the neighbouring star 165 P. III., with the giant refractor of 14.9 inches aperture, detected it to be double, the components being of the 8th and 10th magnitudes, and 10" apart. Struve's 10th-magnitude will, however, be a task for most refractors. He also records η Pleiadum as being double, in the Poulkova Catalogue, 4th and 7th magnitudes, and the Sixth Class of distance.

― A Cycle of Celestial Objects Vol II, The Bedford Catalogue, William Henry Smyth, 1844

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