11 Canis Minorids

The discovery of this radiant came about on the morning of December 11, 1964, while Keith B. Hindley was conducting a telescopic meteor watch so as to "record positional details of Geminid meteors." The watch lasted 3 hours and 45 minutes, during which 26 telescopic meteors were detected. Six of these meteors proved to be true Geminids, but five others clearly emanated from an area 35 arc minutes across centered at RA=117.0 deg, DEC=+12.8 deg. The meteors ranged in brightness from 6.0 to 11.0, and were described as white and swift. On the night of December 13/14, Hindley observed for 4.5 hours, but no trace of activity was noted from the 11 Canis Minorid radiant, which brought Hindley to conclude that the shower possessed a very short duration. Hindley computed the following parabolic orbit.

AOP AN i q e a
157.4 78.0 107.9 0.038 1.0 ---

Hindley noted a similarity between this orbit and that of comet Nicollet-Pons (C/1821 B1), although "the difference of 28 deg in the longitude of the ascending node made it unlikely that these two orbits are in fact related." In 1970, Hindley and M. A. Houlden suggested that comet Mellish (D/1917 F1) might have produced the stream after their adopted radiant of RA=115 deg, DEC=+12 deg produced the following parabolic orbit.

AOP AN i q e a
158 78 89 0.04 1.0 ---

New light was shed on the stream during 1974, while M. Kresakova was investigating photographic meteor orbits in an attempt to suggest a link between comet Mellish (D/1917 F1) and the Geminids. Along the way nine meteors were found which were tentatively referred to as "short-period component B," but later identified with the 11 Canis Minorids. The suggested duration was December 4-15. The average radiant was given as RA=109.3 deg, DEC=+12.4 deg, while the daily motion was given as +0.53 deg in RA and -0.37 deg in DEC. The established orbit was

AOP AN i q e a
150.9 78.8 29.1 0.092 0.942 1.64

The orbit of comet Mellish was given as

AOP AN i q e a
121.3 88.0 32.7 0.190 0.993 27.64

Kresakova concluded that the 11 Canis Minorids might be part of a chain association, whereas comet Mellish produced the December Monocerotids, which produced the 11 Canis Minorids, which subsequently produced the Geminids. Kresakova theorized that the chain could have began following a disruption of comet Mellish.
Visual observations of this radiant were made by the Western Australia Meteor Section during 1979. The overall duration was given as December 7-9, while a maximum ZHR of 1.27+/-0.40 occurred on the 9th from a radiant of RA=116 deg, DEC=+14 deg.

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