Bibcode
Bellot Rubio, L. R.
Referencia bibliográfica
Astronomy and Astrophysics, v.301, p.602
Fecha de publicación:
9
1995
Revista
Número de citas
19
Número de citas referidas
15
Descripción
In this paper we discuss the observational consequences of a dependence
of meteor brightness on the entry angle z_R_, namely the decrease of the
observed rates of meteors and the reduction of the population indices r
for radiant zenith distances larger than zero. These effects, if not
properly accounted for, lead to erroneous values of meteor shower
activity. The first one is corrected by applying a factor cos^-γ^
z_R_ to the observed rates, while the second one requires a correction
of the form r(0deg)=r(z_R_)^b(z_R_)/b(0deg)^. We give general
expressions for γ and b(z_R_)/b(0deg) in terms of the coefficients
relating the absolute magnitude of the meteor to its physical
parameters. High quality photographic data, as well as naked-eye
observations, are analyzed. It turns out that γ=1+1.53logr(0deg)
describes the photographic behavior quite well. For visual observations,
however, an exponent γ=1 should be employed in most cases. We
explain this difference on the basis of a larger path of the meteoroids
at increasing entry angles, which increases the probability of
perception of meteors for visual observers. As regards b(z_R_)/b(0deg),
a dependence b(z_R_)/b(0deg)=1.04-0.04cos z_R_ is suitable for both
photographic and naked-eye records. These values are compared to
predictions resulting from a detailed treatment of the single body
theory. It turns out that the single body approach gives a much stronger
dependence of the meteor brightness on the entry angle than that
obtained from observations. Models including quasicontinuous
fragmentation are therefore necessary.