A072235 Years of recorded observations of Comet Halley.

-240, -164, -87, -12, 66, 141, 218, 295, 374, 451, 530, 607, 684, 760, 837, 912, 989, 1066, 1145, 1222, 1301, 1378, 1456, 1531, 1607, 1682, 1759, 1835, 1910, 1986

Offset

1,1

Comments

This sequence is not well-defined for many reasons (negative years are ill-defined; calendars change often, so when does a year begin?; what does "observed" mean?; what if the comet was observed both at the end of one year and at the beginning of another, as in 1985/1986?; etc.). - N. J. A. Sloane, Jun 24 2007

The first four terms given are years B.C., others are A.D. I do not know if these years necessarily coincide with actual years of perihelion. Some sources and these numbers indicate that the comet's period varies. These years are taken directly from the U.S. National Air and Space Museum link.

Links

Table of n, a(n) for n=1..30.

National Air and Space Museum, Exploring Comets - Historical Records

N.A.S.A., Comet Fact Sheet

Wikipedia, Comet Halley

Crossrefs

See A100748 for another version.

Sequence in context: A078151 A278179 A100748 * A298453 A121378 A191533

Adjacent sequences: A072232 A072233 A072234 * A072236 A072237 A072238

Keyword

sign

Author

Rick L. Shepherd, Jul 05 2002

Status

approved