(meteorobs) Miscellaneous questions

[prospector at znet.com]

Karl,

    NASA ADS archive may be a place for you to research. I was just reading
Harvard paper #315 by Fred Wipple (1947 or 1949) "Seasonal Variations In
the Density of the Upper Atmosphere" as measured using photos of meteors.
That paper may answer some of your questions. Read all about 1920 and
observations from around the world and their papers. It's like plowing a
field full of rocks, tough going to find what you need but it's the real
thing by those who wrote the books. There's a natural extinction of
magnitude of meteors when looking lower in the sky, especially very low.

                                   Dave English
                               Oceanside, California
Quoting Karl Antier <ka.antier at wanadoo.fr>:

> Second, about the Ursid, I read in the IMO shower Calendar that there
> were one possible outburst of the 20s that
> had disappeared. If my memory is good, it's the 1921 one. Why ? Are there
> any clues that show that it wasn't a
> manifestation of that shower ? Or was it due to poor recordings of the
> observers that couldn't help to figure out
> what really happened that year ?
> And the last question deals about Field Of View (FOV). I read once that
> the dipper the layer of atmosphere is, th
> most meteors we see. So that if there were no absorption, we would all
> observe with the center of the FOV closer to
> the horizon.
> Now, imagine the transparency of the sky is excellent, wouldn't it be
> preferable to watch closer from the horizon
> to catch more meteors ? In that case, should corrections be applied to
> calculate ZHR later ?
>
> Karl
>