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(meteorobs) Meteor Activity Outlook for October 6-12, 2000
The waxing moon is becoming more and more of a problem with each passing
day this week. Evening observations will have to endure the bright moon
as it now sets after midnight. The late morning skies are free of
moonlight early in this period but after the weekend the moon is in the
sky most of the night. All positions listed below are exact for Saturday
night/Sunday morning October 7/8. The positions do not change greatly
day to day so these positions may be used during this entire period.
The Giacobinid or Draconid meteor shower is only active from October
6-10. The predicted time of maximum activity is near 0900 Universal Time
on October 8. This shower is generally only active when its parent comet
(21P/Giacobini-Zinner) lies near perihelion. This last occurred in 1998
when ZHR's reached 700 for a very brief period over eastern Asia. This
year one would be lucky to see any activity at all, especially with
the bright gibbous moon in the sky. The normal radiant is located at
17:28 (262) +54, which lies just west of the "Lozenge" of Draco. Marco
Langbroek has pointed out that during "off years" such as 2000 the
radiant may be located further south and a bit east near the position of
17:40 (265) +47, which is on the Hercules/Draco border. This general
portion of the sky lies nearly overhead at dusk for observers located in
northern mid latitudes. As the evening progresses the radiant slowly
sets toward the northwestern horizon so early evening observing is
better. If any shower members should appear they would be very slow
compared to your average meteor.
The Antihelion radiant is now located at 02:00 (030) +12. This position
is in southwestern Aries, a rather blank portion of the sky. Rates
should be 1-2 per hour especially near 0200 local daylight time, when
the radiant lies at its highest point above the horizon. Observers who
send their reports to the I.M.O. should designate those meteors from
Aries as North Taurids (NTA) and those from Pisces and Cetus as South
Taurids (STA). These meteors are slow and the brighter members often
fragment.
The Orionid radiant is located 05:48 (087) +15. This position lies in
northeastern Orion some 8 degrees north of the bright orange star
Betelgeuse. Rates should be close to 1 shower member per hour this week.
Like the other morning sources the Orionids are swift meteors. The
radiant is best placed near dawn when it lies highest in the sky.
The Delta Aurigid radiant is located at 06:12 (093) +49. This position
lies in northeastern Auriga. This area of the sky lies in the
northeastern sky during the evening hours and is best placed nearly
overhead at dawn, as seen from the mid northern latitudes. There have
been other radiants reported as active near this position so it
is possible the the Delta Aurigids possess a filamentary structure with
several active radiants in this same general area. Any swift meteor from
this area is most likely a member of this shower. Although a weak
maximum is expected near October 10th, hourly rates this week are not
expected to be impressive with perhaps 1-2 shower members being seen
each hour during the moonless morning hours.
The Northern Apex source is now located at 07:00 (105) +38. This
position lies in a remote area of eastern Auriga some 10 degrees
northwest of Castor and Pollux, the brightest stars in the constellation
of Gemini. Since this radiant is diffuse any meteors from the eastern
half of Auriga or northern Gemini would be a good candidate. Care must
be taken when distinguishing these meteors from those of the Delta
Aurigids. Both of these sources produce swift meteors. As seen from the
Northern Hemisphere this source should be quite active producing 4-5
meteors per hour near dawn. From the Southern Hemisphere this source
would be much lower in the sky and only producing 1-2 meteors per hour.
The Southern Apex source lies exactly 30 degrees south of its northern
counterpart at 07:00 (105) +08. This position lies on the
Monoceros/Canis Minor border, some 10 degrees northwest of the brilliant
star Procyon. Any swift meteor from eastern Canis Minor, Monoceros, or
southern Gemini has a good chance of being from this source. As seen
from the Northern Hemisphere this source should produce 3-4 meteors per
hour near dawn. Similar rates would be seen from the Southern
Hemisphere.
The Sporadic rates for the Northern Hemisphere are at their annual
maximum. Expected rates of these random meteors would be 2-3 per hour
during the moonlit evening hours and perhaps 10 per hour during the
dark morning hours as seen from rural areas.
Clear Skies!
Robert Lunsford
AMS Visual Program Coordinator
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