Optical Properties of Cometary Nuclei and a Preliminary Comparison with Asteroids
Abstract
Direct CCD observations of cometary nuclei are used to make a preliminary physical comparison with main-belt asteroids of comparable size. The nuclei have been studied within the past 2 yr using charge-coupled devices; the observations of P/Neujmin 1 and P/Tempel 2 are presented here for the first time. The photometric ranges of the nuclei are found to be larger than the ranges of typical main-belt asteroids of similar size, suggesting a systematic shape difference between the nuclei and the small asteroids. The shape difference may be a result of the different collisional histories of the nuclei and asteroids or of anisotropic sublimation of the nuclei. These and other possibilities are briefly discussed. From the scant available information it is suspected that the shapes of the nuclei may be more similar to the shapes of earth-crossing asteroids than to the shapes of main-belt asteroids, consistent with, but not proving, a common origin for the cometary nuclei and the earth-crossing asteroids.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- May 1988
- DOI:
- 10.1086/166351
- Bibcode:
- 1988ApJ...328..974J
- Keywords:
-
- Asteroid Belts;
- Charge Coupled Devices;
- Comet Nuclei;
- Comet Tails;
- Cross Sections;
- Physical Properties;
- COMETS;
- NUCLEI;
- OPTICAL PROPERTIES;
- COMPARISONS;
- CCD METHODS;
- ASTEROIDS;
- PHYSICAL PROPERTIES;
- NEUJMIN 1;
- TEMPEL 2;
- PHOTOMETRY;
- SIZE;
- SHAPE;
- EARTH-BASED OBSERVATIONS;
- COLLISIONS;
- SUBLIMATION;
- EARTH-CROSSERS;
- TELESCOPE METHODS;
- CALCULATIONS;
- HYPOTHESES;
- FORMATION;
- DENSITY;
- Astrophysics; Comets;
- ASTEROIDS;
- COMETS