An Example: San Jose, California
April 24 through May 8. Hale-Bopp then
disappears from viewing with the naked eye
in the Northern Hemisphere

Note: Look outside around 9:30 PM

U.S. Naval Observatory
Astronomical Applications Department

Comet Hale-Bopp Positions

The following table gives the positions of comet Hale-Bopp during early 1997 as seen from the specified place. The period covered is 16 February through 31 July. Morning viewing dates are listed first, followed by evening viewing dates. The morning viewing data are for the beginning of astronomical twilight; the evening viewing data are for the end of astronomical twilight. On days without moonlight interference, these times will be the most favorable for viewing the comet - it will be at its maximum altitude in a completely dark sky. Only dates on which the comet is at least 5 degrees above the horizon at these times are listed. The columns are, from left to right: date and time in Universal Time; date and time in local zone time; apparent right ascension; apparent declination; altitude above the horizon; azimuth (measured eastward from north); total visual magnitude; moonlight interference indicator ("M" when Moon is above the horizon); and the Moon's phase.

Daylight time began in the U.S. on 6 April and this is reflected in the local zone time for U.S. cities and towns (if Form A was used for input).

The comet was at conjunction in right ascension with the Sun on 21 March, that is, it passed directly north of the Sun in the sky on that day, moving eastward. This marked the time at which the comet moved from the morning sky to the evening sky, although at middle northern latitudes there was a week or more around 21 March when the comet was visible both morning and evening.

At high latitudes in the spring there is a date after which astronomical twilight lasts all night. For these places and dates, the data are tabulated for astronomical midnight, when the Sun is at lower transit and the sky brightness is at a minimum. This is indicated by an "m" symbol (for midnight) next to the local time.

The comet right ascensions, declinations, and magnitudes are based on the JPL ephemeris of 27 January 1997 by D. K. Yeomans.

See also Hale-Bopp observing notes.

COMET HALE-BOPP -- EARLY 1997
POSITIONS FOR SAN JOSE, CA
LON -121.9 LAT +37.3

Morning Observation Times -- Beginning of Astronomical Twilight

UT date/time Local date/time RA Dec Alt Az Mag Moon Phase
h m o o o

APR 24 4:25 APR 23 21:25 4 16 +30.4 15.9 296 1.1 M

APR 25 4:27 APR 24 21:27 4 20 +29.7 15.3 296 1.1

APR 26 4:28 APR 25 21:28 4 24 +29.1 14.7 296 1.2

APR 27 4:29 APR 26 21:29 4 27 +28.4 14.1 295 1.2

APR 28 4:30 APR 27 21:30 4 31 +27.8 13.4 295 1.3

APR 29 4:32 APR 28 21:32 4 35 +27.1 12.8 295 1.3

APR 30 4:33 APR 29 21:33 4 38 +26.5 12.1 294 1.4 LQ

MAY 1 4:34 APR 30 21:34 4 41 +25.9 11.4 294 1.4

MAY 2 4:36 MAY 1 21:36 4 45 +25.3 10.7 294 1.5

MAY 3 4:37 MAY 2 21:37 4 48 +24.7 9.9 294 1.5

MAY 4 4:38 MAY 3 21:38 4 51 +24.1 9.2 293 1.6

MAY 5 4:40 MAY 4 21:40 4 54 +23.5 8.4 293 1.6

MAY 6 4:41 MAY 5 21:41 4 57 +22.9 7.6 293 1.7

MAY 7 4:42 MAY 6 21:42 5 00 +22.3 6.9 293 1.7 New

MAY 8 4:43 MAY 7 21:43 5 02 +21.7 6.1 293 1.8

MAY 9 4:45 MAY 8 21:45 5 05 +21.2 5.3 293 1.8 M

M = Moon above horizon.