We had to research questions, does the radiant of the outbreak members coincide with the September Perseid Shower’s radiant and is the orbit that of a long period comet or is it a short period comet.
Here is a comparison between the data from the IMO shower list, Molau’s Shower 68 and those derived form the BC videos.
IMO BC Shower 68
λsol 166°7 166.9089 n/a
α 60° 47.7° 48.0°
δ 47° +39.5° 39.5°
Vinf 64 km/s 65.47 km/s 65 km/s
ZHR 5 ˜25 n/a
The best fit is with Sirko Molau’s (Molau 2008) Shower 68 and not the SPE. Much more research is needed before we can declare this is true or just a coincidence. This should be an open question.
As Esko calculations show the source for this outbreak is in a Jupiter crossing orbit with a mean period of 78.54 years. This puts it into a Halley type orbit (short period).
More to come…
Orbital parameters (equinox J2000)
year: 2008
month: 9
day: 9.347222
q(AU): 0.719
a (AU): 18.34
e: 0.961
i (deg): 139.08
omega: 245.36
node: 166.909
pi: 52.27
Vinf: 65.47 km/s
Vgeo: 64.32 km/s
Vh: 41.39 km/s
Period: 78.54 years
Q (AU): 35.96
1/a: 0.055
Solar Long: 166.9089
Heliocentric Radiant
ß 33.77
λ 37.38
Vh 41.39 km/s
α Geo 47.40
δ Geo +39.50
Days to perihelion: 36.7
Orbit: ecliptic retrograde
Meets in: descending node
Ratio of revolution to Jupiter: 0.15:1
Jupiter crossing: Yes
Observed Radiant Position
Local sidereal time -6.245 deg or an hour angle of 306.49
Data for equinox date: Ra: 42.27 Dec: +39.57
Data equinox J2000: RA 47.28 Dec: +39.53
Vinf: 65.47 km/s
Geocentric Radiant Position
Local sidereal time: -6.245 deg or an hour angle of 306.37
Data for equinox date: Ra: 47.38 Dec: +39.53
Data equinox J2000: RA: 47.40 Dec: +39.50
Vgeo: 64.32 km/s
Refs cited and develop Shower 68 discussion edited: 2010-09-24 by jlb