Observations of Eros

The newly discovered planet Eros is now the object of special investigation at the Harvard Observatory. At the present time the planet is nearer the earth than any other heavenly body with the exception of the moon, and is in opposition with the sun. Owing to its favorable position its solar parallax and brightness may be accurately determined.

A photographic plate was taken of Eros at Arequipa, Penn, in April and the first of a long series in Cambridge was obtained in July. Owing to its great distance from the earth and consequent faintness a time exposure of two hours and a half was necessary. Plates are now being taken in the early evening, the middle of the night, and the early morning with time exposures of from one to five minutes only. The plates obtained in the early evening and early morning are carefully compared in order to determine the exact position of the planet. Tests for brightness are also made frequently with the eight inch Draper telescope.