The American Ephemeris and Nautical AlmanacU.S. Government Printing Office, 1891 |
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Common terms and phrases
17 Tauri 27 Arietis 47 Geminorum Aldebaran Aldebaran E Antares Antares W Apparent Declination APPARENT PLACES Apparent Right Ascension Aquilæ Arietis W ASCENSION AND DECLINATION Ascension Declination Auriga Cancri Cephei CONJUNCTION IN R. A. d h m Declination North Declination Right Declination Draconis eclipse Ephemeris Fomalhaut Frid Geminorum Geocentric GREENWICH MEAN NOON Horizontal Parallax Hour hour-angle July June JUPITER JUPITER W Latitude Leonis LUNAR DISTANCES MARS Mean Solar Date Midnight Minute moon MOON'S RIGHT ASCENSION Name and Direction Parallax Pegasi Pollux Pollux W PREDICTION OF OCCULTATIONS Red'ns Regulus Regulus W Right Declination Ascension Right Declination Right Sagittarii satellites SATURN SATURN W Scorpii Semi semidiameter Sept Sidereal Spica Spica W star STAR'S AT CONJUNCTION Sun's Tauri Thur tion North TRANSIT AT WASHINGTON TRUE LONGITUDE Tues UPPER TRANSIT Ursa Minoris VENUS Virginis WASHINGTON MEAN
Popular passages
Page 489 - 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 490 - Ж, and the astronomical time is had without further change. To change astronomical to civil time, we simply write PM after it, if it is less than 12 hours. If greater than 12 hours, we subtract 12 hours from it, add 1 to the days, and write AM For example, January 3d, 23 hours, astronomical time, is January 4th, 11 o'clock, AM, civil time.
Page 497 - 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 500 - X, and directed toward the north; .v and y are then the co-ordinates of the point in which the axis of the shadow intersects the fundamental plane. The angle d, of which the sine and cosine are both given, is the declination of that point of the celestial sphere toward which the axis of the shadow is directed; this direction being that from the earth toward the moon and sun.
Page 495 - 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 408 - In the year 1887 there will be four eclipses, two of the Sun and two of the Moon. I.
Page 494 - The moon's semidiameter and horizontal parallax are required for all observations of the moon. When great precision is needed, the hourly differences should be first interpolated for half the interval of Greenwich time from noon or midnight, and a correction applied to the horizontal parallax for the latitude of the place of observation. The Mean Time of the Moon's Upper Transit at...
Page 490 - 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 490 - The civil day begins twelve hours before the astronomical day; therefore the first period of the civil day answers to the last part of the preceding astronomical day, and the last part of the civil day corresponds to the first part of the astronomical day.