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Re: Radiants, was Re: (meteorobs) A blank meteor reporting form
Marco>And he is right that it has little meaning to use 5
>degrees for one and 10 degrees for another stream. Except perhaps for
>using a larger diameter for those streams you know have diffuse radiants
>(e.g. alfa Capricornids).<<
Mark>>It is my understanding that this is how the various size diameters came
into
existence...along with a "best-fit" trade-off in misclassified sporadics and
shower members. <<
I don't really think so Mark. The assignment of various large, inaccurate
radiants to different showers indicates to me that the originators weren't
thinking about diffuse radiants, but thought these were the actual diameters
at the time. In the example that marco mentions above about having 10 degrees
for a diffuse radiant such as the alpha Capricornids (actually they had
assigned 8 degrees for the capricornids), wouldn't hold water either. If you
have a diffuse radiant, you simply magnified the area around the radiant
location according to how far the meteor appears from the radiant. There is no
need to assign a ballooned radiant diameter from the get go without any
meteors present. I don't know how diffuse the Capricornids are, but I find it
rather amusing that IMO had 10 degrees assigned to the Orionids... when it has
an actual sharp radiant of 0.84 degrees, and 8 degrees for a supposedly
diffuse radiant for the capricornids. I can see giving the capricornids a
slightly wider girth due to zenithal attraction would be greater for it's
slower meteors than the faster orionids. But apparently this wasn't a
consideration?
George Zay