Immersion Occultation of y. γ Oh. 34m. 27.8s. M. 2'36" South of the Centre. 0 48 D's S. D. at Im. 14' 46.6". Configuration of the Satellites at the Immersion. 2 31 This occultation will be visible throughout the United States, and will be the most interesting in the year. Immersion 9h. 40m. 45.6s. A. 0′ 31′′ North of the Centre. 10 56 17.6 2 44 South. D's S. D. at Im. 16′ 34.7''; at Em. 16' 33.9". *December 17th. Occultation of Aldebaran. Immersion 4h. 53m. 35.4s. A. 0' 6" North of the Centre. 5 47 25.5 4 19 South. D's S. D. at Im. 16' 44.0"; at Em. 16' 47.1". D's S. D. at Im. 15′ 49.7''; at Em. 15′ 46.2". h's S. D. 8.55". 10 56 2.7 Appulses of the Moon to Planets and Stars in 1831, at Boston; all, or nearly all, of which will be Occultations in some part of the United States. OCCULTATIONS OF THE PLANETS* AND OF THE STARS REGULUS AND ALDEBARAN, VISIBLE IN 1831 IN THE CITY OF CHARLESTON, SOUTH CAROLINA, IN MEAN TIME, FOR THE MERIDIAN OF CHARLESTON. *It was originally intended to compute all the occultations of stars, of not less than the fifth magnitude, for Charleston and Washington, as well as for Boston; but the calcula tion of the eclipse of the 12th of February occupied so much time (five months), that we were compelled to defer carrying our intention into full effect, until another year. APPULSES OF THE MOON TO THE PLANETS AND THE PRINCIPAL FIXED STARS, AT CHARLESTON, IN 1831. The importance of large eclipses of the Sun and of occultations of stars and planets by the Moon, for the determination of terrestrial longitude (the latitude being always easily ascertained), has long been known. When thus carefully determined, it will be as near to the truth as when deduced from a very large number of lunar distances, or of transits of the Moon and a star; but where the tables of the Moon are relied on, the longitude, even thus obtained, is still somewhat uncertain, on account of the small error which is sometimes found in them; if, however, it is deduced from a corresponding observation of the same eclipse or occultation made in one of the observatories of Europe, or in any other place, of which geographical position is well determined, it will be free from this as well as other sources of error, if the observations are correctly made in both places. On another account, the subject of occultations has at all times been an interesting and important one, both to the practical and theoretical astronomer; viz. they frequently present some remarkable phenomena with respect to light, when the edge of the Moon comes in contact with the star, the star sometimes appearing to be projected on the disc of the Moon. This circumstance has lately been very particularly attended to, and numerous instances are given by members of the Astronomical Society of London, who suppose that this appearance is more frequent (or at least more frequently recorded) as to Aldebaran, than as to any other star, accompanied, however, with anomalies, for which it is difficult to account.* It is therefore hoped that our astronomers will be induced to look out for the occultations of this star, not only with a view to ascertain the longitude of the place of observation, but to determine whether it does not appear. projected on the face of the Moon; in doing this, particular attention should be paid to the following circumstances. *See a paper read before the Astronomical Society of London, by Mr. South, their President, in the transactions of that Society in 1829; also remarks on the anomalies observed in the occultations of Aldebaran of August 21st, October 15th, and December 9th, same year. |