RECENT DETERMINATIONS OF STELLAR PARALLAXES BY PHOTOGRAPHIC METHODS. A REVIEW

Abstract

i. of 260 Derived from Photographs, by S. A. Mitchell, assisted by C. P. Olivier, H. L. Alden and others. Pubi. Leander McCormick Obsy., Vol. Ill, 1021. 2. Determinations of Parallaxes at the Allegheny Observatory, by Frank Schlesinger. A. /., 33, 9, 1920. (The details of these 269 parallaxes and of 50 earlier ones are given in Pubi. Allegheny Obsy. , Vols. 4 and 5, 1920, which (except Vol. 4, No. 1) have been distributed quite recently. several papers in these volumes are signed by Dr. Schlesinger and ten assistants.) 3. of Fifty-two Stars, by Georges Van Biesbroeck and Mrs. Hannah Steele Pettit. Pubi. Yerkes Obsy., Vol. IV., Pt. Ill, 1920. (Vol. IV, Pt. I, 191 7, gives details of 103 parallaxes determined earlier by Slocum, Mitchell, Lee, Joy, and Van Biesbroeck, with a summary of the 28 determined by Schlesinger at the same observatory.) 4. The Parallaxes of Fifty Stars Determined at the Sproul Observatory. Second List, by John A. Miller, with the cooperation of John H. Pitman and Hannah B. Steele. Sproul Obsy. PubL> No. 5, 1920. (No. 4 of these Publications, issued earlier, contains the first list of 50 parallaxes.) 5. The Photographic Determination of Stellar Parallaxes with the 60-inch Reflector, Fourth Series, byAdriaan vanMaanen. Contrib. Mi. Wilson Obsy ' No. 182, 1920. (Contrib. Nos. in, 136, and 158 contain van Maanen's earlier parallax series derived since 1915 with the same telescope. In all no parallaxes are listed, including those of several nebulae.)