A Photographic Study of the Draconid Meteor Shower of 1946.
Abstract
The present paper contains a discussion of 204 Draconid (Giacobinid) meteors photographed at North Bay, Ontario, Canada, during the night of October 910,1946, and reduced at the Massachusetts Institute of Technology, Cambridge, Mass. The fundamental data pertaining to each individual meteor are assembled in Table 4. The cosmic spread of the radiant turns out to be 6 2, more than half of which is probably due to observational errors. This is much less than the spread of any of the other major showers investigated so far and, together with the fact that no Draconid meteors are observed except in the immediate neighborhood of the parent-comet, points to a relatively early stage of disintegration of the swarm. The visual paths of the Draconid meteors proved to be of considerably shorter duration than those of most normal meteors and, considering their low geocentric velocity, were visible at abnormally great heights (between 90 and 98 km, on tbe average). The observed decelerations would point to masses which are, o the average, one hundred times smaller than those of other meteors of comparable brightness and geocentric velocity. All this indicates that the Draconid meteors are probably composed of "soft" material, which is more easily vaporized by friction in the earth's atmosphere than that of other meteor particles.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- January 1950
- DOI:
- 10.1086/145243
- Bibcode:
- 1950ApJ...111..104J