A low-dispersion spectral video camera for observing lunar impact flashes

Earth, Planets and Space

Table 5 Parameters of meteoroid streams

	N. Taurids	α-Centaurids	η-Aquariids	Sporadic
Radiant α^a [degree]	52	208	332	–
Radiant δ^a [degree]	21	−59	−3	–
ZHR_(max)^a or HR^b for sporadic [meteors h⁻¹]	5	6	50	10
λ_max ^a [degree]	230	319.2	45.5	–
b ^c [degree⁻¹]	0.026	0.18	0.08	–
V ^{a, d} [km s⁻¹]	29	56	66	17
m₀ ^e [× 10^–6 kg]	1.0	0.062	0.031	9.8
s ^f	1.90	1.75	1.95	2.19
γ^g	0.88	0.96	0.97	0.71
σ or \({\Xi }\) ^h	1	1	1	–

Besides these parameters, we set the detection limit to be 4 × 10⁴ J for the luminous energy of lunar impact flash sources and the conversion efficiency from meteoroid kinetic energy to luminous energy to be 0.2%
^aIMO Meteor Shower Calendar (2021)
^bLiakos et al. (2020)
^cThe slope of ascending and descending activity profiles: Table 3b in Jenniskens (1994)
^dGeocentric velocity
^eMeteoroid mass that corresponds to a terrestrial meteor of 6.5 in magnitude calculated from Eqs. (1) and (2) in Hughes (1987)
^fMass index of the shower, which is connected to the population index r as \(s = 1 + 2.5\log_{10} r\)
^gThe quotient between the gravitational focusing factors of the Earth and the Moon
^hThe distance between the Earth and the stream center divided by the distance between the Moon and the center