Photoelectric discovery of a 52-Hr periodicity in the nuclear activity of P/Halley

Research output: Contribution to journalArticlepeer-review


Intermediate band photemetric observations of P/Halley performed in November and December 1985 at the Wise Observatory reveal a cycle of 52 hr in the lightcurve emitted from the near-nucleus zone. Significant periodic variations have been found in the color index M(5140)-M(7000), i.e., the magnitude difference between measurements through two bandpass filters centered around emission lines of C2 and of H2O+, respectively. There is no apparent cyclic variation in either the blue or the red continuum radiation from the same region. The periodic line variation is interpreted by us as the modulation of the molecular density of the two species in the inner coma caused by variation in mass ejection from the spinning nucleus of the comet.

Original languageEnglish
Pages (from-to)418-429
Number of pages12
Issue number3
StatePublished - Dec 1986


Dive into the research topics of 'Photoelectric discovery of a 52-Hr periodicity in the nuclear activity of P/Halley'. Together they form a unique fingerprint.

Cite this