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(meteorobs) Meteor Activity Outlook May 26 - June 1, 2000
The moon is now at last quarter and totally out of the way for evening
observers. Unfortunately for those located high in the Northern
Hemisphere evening twilight does not end until late offsetting the lack
of lunar interference. Those of us located further south can start
watching earlier in the evening but potential observing targets are
scarce and of low activity.
The first target of the evening could be the antiapex (SPO/XPX) sporadic
source. This is located 90 degrees east in the sun in the evening sky
with subcenters located 15 degrees north and 15 degrees south of the
ecliptic. It would be interesting to see if any activity could be seen
coming from 10:32 (156) +24, just east of the "sickle" of Leo or from
10:32 (156) -6, in east-central Sextans. These two areas would provide
the most likely activity but any meteor from the entire area of Leo and
Sextans would most likely be from this source. Expect to see only 1 to 2
meteors per hour from this source.
The second source of activity for evening viewers would be the
antihelion (ELC) radiant now located near 17:22 (261) -23. This area of
the sky is found near southern Ophiuchus between Scorpius and
Sagittarius. It is found in the southeastern sky during the evening
hours and is best seen just after midnight. At this time of year
there are many different subradiants located in the
Scorpius-Ophiuchus-Sagittarius area. It is impractical for the visual
observer to try to sort these so it is suggested that they all be
called "ECL's" or "SAG's". This source of activity is more productive
than the antiapex with up to 5 meteors per hour this time of year.
The Omega Scorpids (OSC) and the Beta Corona Australids (CAU) may be
outlying members of the antihelion source. They are far enough away from
the center of that source that it may be possible to classify them
separately from plots. The Omega Scorpids are located at 15:36 (236) -20
on Saturday evening. This position is near the Libra-Scorpius border
west of the the "Head" of Scorpius. These meteors would be very slow
whether seen close or far from the radiant. On the same evening the Beta
Corona Australid radiant would be located at 20:08 (300) -39. This is in
the extreme southeastern portion of Sagittarius, east of Corona
Australis. These meteors are much faster than either the OSC's or your
typical antihelion meteor. I would expect rates from these two sources
to be less than 1 meteor per hour.
Later during the night there are 3 more possible sources of activity.
The moon will interfere during the early part of this period but after
the weekend it will be a thin crescent low in the eastern sky.
The Apex (SPO/APX) sources are rapidly moving northward and becoming
better situated for northern observers. On Sunday morning the northern
branch will be located at 22:32 (336) +6. This location is in
southwestern Pegasus between the stars Theta and Xi in the "neck" of the
winged horse. On the same morning the southern branch is will be located
at 22:32 (336) -24 which is on the Pisces Austrinus/Aquarius border,
northwest of the 1st magnitude star Fomalhaut. The entire area of
western Pegasus, Aquarius, and Pisces Austrinus can be considered part
of this source. Meteors from this source would be swift except when
appearing near the radiant source.
On Sunday morning the Arietids (DAR) are active from a radiant located
at 02:28 (039) +18 . This is located in central Aries 10 degrees
southeast of the 2nd magnitude star Hamal. This is only 25 degrees east
of the sun so activity can only be seen shortly before the onset on
dawn. Any activity would likely appear as "Earthgrazers", which are long
meteors lasting several seconds shooting upward from the horizon. Your
chance of seeing one of these rare meteors increases as we approach the
June 7 maximum. Current rates are most likely less than 1 shower member
per hour.
Finally the sporadic rates are near their annual minimum levels for
Northern Hemisphere observers. I would expect evening observers to see
2-3 per hour and morning observers to see 6-8 with the slight lunar
interference. Observers in the Southern Hemisphere could easily see
twice these amounts.
Clear Skies!
Robert Lunsford
AMS Visual Program Coordinator
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