Gamma Piscids

The discovery of this stream should be attributed to Zdenek Sekanina, who established its existence from data gathered during the two sessions of the Radio Meteor Project. The 1961-1965 session revealed only nine definite meteors from the Gamma Piscids during the period of September 10-October 5. The date of the nodal passage was determined as September 24.0 (λ=180.6°), while the average radiant was RA=349.6°, DECL=+2.9°. The 1968-1969 session picked up 35 members of this stream during August 26-October 22. The date of the nodal passage was calculated as September 22.2 (λ=178.8°), at which time the radiant was at RA=342.3°, DECL=+7.7°. The orbital elements were given as

ωΩiqea
S1973253.7180.63.90.7050.7022.366
S1976247.8178.87.60.7410.7162.606

The Author has found no trace of activity from this stream during the 19th century and the first half of the 20th century among the writings of William F. Denning, Alphonso King, Ronald A. McIntosh, Cuno Hoffmeister or Ernst Opik. On the other hand, the Author has located four photographic meteors among the 2529 orbits published by Richard E. McCrosky and Annette Posen in 1961. These not only add support to the very existence of this stream, but obviously indicate that visual observations should be possible.

The photographic meteors were detected during the 1952-1954 Harvard Meteor Project and indicate a duration of September 19-October 2. The apparent date of the nodal passage is September 26 (λ=183.0°), while the average radiant is RA=351°, DECL=+10°. The average orbit is

ωΩiqea
255.3183.08.00.6950.7232.509

Interestingly, a fairly recent visual detection of this shower was made during the 1970's. A decade-long visual survey of meteors was conducted by M. Buhagiar (Perth, Western Australia) which involved the plotting of 20,974 meteors and the determination of 488 radiants. The Gamma Piscids were detected on five occasions, revealing a duration of September 21-28. Maximum was said to have generally occurred on September 25 from RA=350°, DECL=+5°. The highest hourly rate was typically given as 4.