L'ovni de Tananarive en 1954

hal9000 a écrit:Pardon Oncle Dom j'avais pas noté ton message sur l'heure pourquoi Stellarium indique heure locale TU+2h45 alors? Erreur?

astrosurf a écrit:Using observations made by New Zealand observers during the 1920's and early 1930's, Ronald A. McIntosh found seven apparently separate areas of activity from the relatively small constellation of Pisces Austrinus which reached maximum at different times between mid-July and mid-August. The most prominent shower was called the "Alpha Pisces Australids" (the same name Denning gave to the 19th Century observations), the existence of which was based on 24 visual radiants. The duration was given as July 26-August 8, during which time the radiant moved from RA=337 deg, DEC=-33 deg to RA=350 deg, DEC=-30 deg. The other six radiants isolated by McIntosh are as follows:
Pisces Australids: Based on 3 visual radiants, the duration was given as July 28-August 3, while the average radiant was at RA=326 deg, DEC=-26 deg.
Theta Pisces Australids: Based on 2 visual radiants, the duration was given as August 12-14, while the average radiant was at RA=327 deg, DEC=-32 deg.
Beta Pisces Australids: Based on 11 visual radiants, the duration was given as July 14-22, while the average radiant moved from RA=330.5 deg, DEC=-30 deg to RA=339 deg, DEC=-30 deg.
Lambda Pisces Australids: Based on 5 visual radiants, the duration was given as August 5-14, while the average radiant moved from RA=334 deg, DEC=-27.5 deg to RA=339 deg, DEC=-26 deg.
Epsilon Pisces Australids: Based on 3 visual radiants, the duration was given as August 13-14, while the average radiant was at RA=338 deg, DEC=-24 deg.
20 Pisces Australids: Based on 2 visual radiants, the duration was given as August 8-9, while the average radiant was at RA=340.5 deg, DEC=-27 deg.
As noted earlier, there is a period of complete neglect of this meteor shower following the 1937 observations of Hoffmeister's group, but observations were finally resumed in 1953. In that year, radar equipment at Christchurch, New Zealand observed a "highly probable" Pisces Australid radiant at RA=328 deg, DEC=-27 deg during July 21-26. The shower was considered quite strong.
During 1960, a more elaborate radar survey was conducted by B. L. Kashcheyev and V. N. Lebedinets at the Kharkov Polytechnical Institute (USSR). They detected 32 meteors from this stream during July 16-August 13, and concluded that maximum came on July 26 (solar longitude=123 deg), at which time the radiant was at RA=340 deg, DEC=-26 deg. From this data, the first orbit was computed which indicated a 45 deg inclination and a semimajor axis of 4.31 AU.

The Author has located one photographic meteor among the more than 2000 orbits obtained during the Harvard Meteor Project of 1952-1954. It is listed in MP1961 and was designated 3443. It was detected on July 28, 1952, from RA=338 deg, DEC=-27 deg.
AOP =131 ; AN =305 ; i =42 ; q =0.19 ; e =0.98 ; a =7.50

marcassite a écrit:Comme HAL9000 le montre, la dérive des radiants peut jouer dans cette affaire qui date. Or on ignore de quand datent les données de dérive issue de Réforme ... J'ai fouiné et trouvé ces infos pour des données anciennes :
...
http://www.astrosurf.com/sliop/meteor/alpha%20pisces%20australids.htm

Si ça peut servir ...