Comet West 1976 VI: discrete bursts of dust, split nucleus, flare-ups, and particle evaporation.
Abstract
Analysis of four small-scale photographs of Comet West taken on 5-8 March 1976 offers evidence of five discrete bursts of dust from the comet's nucleus between 19 and 28 February, i.e., from six days before perihelion to three days after it. The images of the comet on the photographs were computer-enhanced to increase the contrast of the fine structure. The timing of two of the bursts suggests very strongly that they accompanied the two breakup events that gave birth to the companion nuclei D and B. The primary breakup, on 19 February, also coincides with a 2-magnitude surge in the comet's brightness. Some of the other dust bursts might be correlated with less conspicous flare-ups observed in both the visual brightness and the thermal emission of the comet. A distinct intensity discontinuity makes up the trailing boundary of the main body of the dust tail. When the observed position of the discontinuity is corrected for an effect of particle-expulsion velocity, it is found to correspond to dust expelled from the comet exactly at perihelion. It is suggested that because of its timing, the intensity discontinuity could be a product of particle evaporation sharply peaked at perihelion.
- Publication:
-
The Astronomical Journal
- Pub Date:
- December 1978
- DOI:
- 10.1086/112380
- Bibcode:
- 1978AJ.....83.1675S
- Keywords:
-
- Astronomical Photography;
- Comets;
- Interplanetary Dust;
- Particle Emission;
- Bursts;
- Comet Nuclei;
- Comet Tails;
- Evaporation;
- Image Enhancement;
- Light Curve;
- Time Response;
- WEST;
- COMET;
- NUCLEI;
- BRIGHTNESS;
- PERIHELION;
- PARTICLES;
- EVAPORATION;
- COMET TAILS;
- BURSTS;
- DUST;
- STREAMERS;
- RADIATION;
- PRESSURE;
- ACCELERATION;
- Astrophysics; Comets;
- Comets:Bursts;
- Comets: Nuclei;
- Comet 1976 VI West