A little ramble through 19th century astronomy - occultation of Pleiadum in 1876

 Nature, January  20^th  1876

Atlas 27 Pleiadum

A very interesting observation was made at Strasburg on the occasion of the occultation of this star – a Struve’s difficillima – on the 7^th of the present month. As we recently stated, this star does not appear to have been seen double since the last Dorpat observation in 1830. On the 7^th inst., however Herr Hartwig observing at Strasburg with an excellent Fraunhofer of 42 lines aperture power 159, remarked that the star did not disappear instantaneously ; after the principal mass of light had vanished there remained a luminous point for about six tenths of a second, a circumstance which favours the duplicity of the object notwithstanding the failure of recent efforts to divide it.

It brings to our attention Burg’s observation of the occultation of Antares 1819 April 13, when at emersion the star appeared to suddenly increase from one of the sixth or seventh magnitude to one of the first, a phenomenon no doubt attributable to the existence of the small companion on the parallel, preceding the principal star (*Natrure, vol xii,p308).

The next occultation of the Atlas – Pleiadum on February 3 , will not be visible in this country, but may be well observed in the United States. The American ephemeris gives the time of immersion for Washington; at the observatory of Hamilton College, Clinton, NY so actively conducted by Prof. Peters, the immersion takes place at 11h 13m, and emersion at 12h 4m.

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