# The American Ephemeris and Nautical Almanac

### Popular passages

Page 482 - XII contains also the Phases of the Moon and the dates of the Moon's Perigee and Apogee, or least and greatest distances from the earth. Pages...
Page 477 - A Solar Day is the interval of time between two successive transits of the sun over the same meridian ; and the hour-angle of the sun is called Solar Time.
Page 478 - PM The Astronomical Day commences at noon on the civil day of the same date. It also comprises twenty-four hours, but they are reckoned from 0 to 24, and from the noon of one day to that of the next following. The astronomical as well as the civil time may be either apparent or mean, according us it is reckoned from apparent noon or from mean noon.
Page 485 - Equinoxes is really the astronomical nutation; that given In Longitude is the correction to be applied to the longitude of the body referred to the mean equinox, in order to obtain that longitude as referred to the true equinox. When the correction is positive, the true longitudes are greater than those referred to the mean equinox; while the contrary is true when the correction has the negative sign. The equation In RA is equal to that in longitude, multiplied by the cosine of the obliquity of the...
Page 484 - ... next below it. In the case of Mercury, this intermediate date is mean noon of the day immediately following ; in the case of Venus, Mars, Jupiter, and Saturn, it is mean noon of the second day following ; and in the case of Uranus and Neptune, mean noon of the fourth day following. Pages 264 — 271 contain the rectangular co-ordinates of the centre of the sun, referred to the centre of the earth as the origin, and to the true equator and equinox of each date as the circle and point of reference....
Page 483 - Greenwich time we have the following rule : — Find in the Almanac the' two distances between which the true distance falls ; take out the nearer of these, the hours of Greenwich time over it, and the PL of Diff.
Page 478 - The sidereal hours are counted from о to 24, commencing with the instant of the passage of the true vernal equinox over the upper meridian, and ending...
Page 503 - The mean declinations of stars are taken from Boss's paper in the Report of the Northern Boundary Commission, Washington, 1879, for all stars found therein. The declinations of all the other stars have been reduced to the same standard, except those of the additional ones above, which have been taken partly from the Astronomische Gesellschaft list, and partly from places in recent catalogues. To the apparent places of Sirius and Procyon have been applied the periodic corrections resulting from AUWERS'S...
Page 503 - Octantis, have been corrected from data furnished by Dr. GOULD ; while the remaining nine are, as before, from the British Nautical Almanac for 1848. The right ascensions of the additional stars in the general- list, whose apparent right ascensions are given in a subsequent section, have been taken partly from the Catalogue of ioç8 Standard Clock and Zodiacal Stars, forming Part IV of Vol.