Copernicus Volume 2; An International Journal of Astronomy (Paperback)

This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1882 Excerpt: ...observations. This comparison gave for the epoch 1777 5 values of the well-known constants m and n. The latter constant is independent of constant errors in the two catalogues, while m depends on the absolute Right Ascensions. For this reason Bessel some years later returned to the question (Astr. Nachr. No. 92), as both the Konigsberg Catalogues for 1815 and 1825 and Lindenau's new determination of the constant of Nutation showed the need of a positive correction to Piazzi's Right Ascensions. It appears that Piazzi founded his determination of the Equinox on observations made in the years 1803 to 1805 when the Nutation was very near its positive maximum, and accordingly his Right Ascensions became too small, the constant of Nutation used by him being too large. In the same manner Bradley's Right Ascensions turned out too large. The corrections to Bradley and Piazzi found by Bessel were respectively--0"-5 and + 1"-585. The rectified values of m and n for 1777-5 compared with Laplace's Theory gave two VOL. II. T values of the correction to the theoretical Lunisolar Precession, which were brought to equality by increasing m and decreasing n by equal amounts. Bessel's final result for the constant of General Precession, reduced to 1800 is--50"-2235. This result is founded on an investigation entirely free from arbitrary assumptions, and not until after the publication of Dr. Auwers' new reduction of Bradley's observations (and possibly not even then) will it be practicable to deduce a sensibly different result from a renewed discussion of the same materials if we except the modification which a new determination of the equinoxes of 1755 and 1800 will introduce, to which matter we shall return later on. We have certainly since 1826 (when Bessel's...