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(meteorobs) Meteor Activity Outlook March 24-30
The moon will reach last quarter on the Tuesday the 28th. This is the
time when it rises near midnight and is close to the meridian (due
south) at dawn. This certainly does not help morning observers but the
intensity of the "half moon" is much less than near full so observations
at any time of the night are still possible if you can keep the moon out
of you line of sight.
Evening observers will be happy this weekend and beyond as the moon
rises late in the evening. This will allow a good look at the antiapex
radiant and a fair look at the antihelion Virginids. The antiapex is a
large radiant located 90 degrees east of the sun along the ecliptic. For
those new to studying meteors, the radiant is the area of the sky that
seems to "produce" meteors. Shower members can appear anywhere in the
sky moving in any direction but if their path is traced backward they
will all intersect in one general area of the sky. Meteoroids catching
up to the Earth from behind will be produced from the antiapex radiant.
Since both the Earth and the meteoroids are moving in the same direction
the entry velocity of these particles will be very slow. The center on
this radiant on Saturday evening will be near 6:19 +23 which is in
Western Gemini near M35. This is the best possible time to look for this
activity from the Northern Hemisphere as the radiant is located high in
the sky at dusk. The opposite is true in September as the antiapex
radiant will be located much lower in the southwest at dusk. The radiant
moves one degree eastward per night if you cannot watch on Saturday.
Rates will most likely be low but there have been very little studies
done on this radiant. As most showers peak during the early morning
hours, watching for this activity would be an important way to
contribute valuable data during a convenient hour!
The radiant for the anthelion (opposite the sun) Virginids are located
at 13:00 -04 on Saturday evening. This position is in central Virgo
nearly halfway between the bright star Spica and the famous 3rd
magnitude double star Porimma. This area of the sky rises near dusk and
is fairly high in the southeast as the moon rises. As with the antiapex
radiant, the radiant area is large (rather than a small point) and moves
one degree eastward per night. Being near the celestial equator also
causes a fairly rapid change in declination for the radiant amounting to
one degree southward every third day. The Virginids are caused more or
less by particles intercepting the Earth from outside the Earth's orbit
traveling toward the sun. The entry velocity it a bit more than the
antiapex meteors, but still much slower than your average meteor.
Only one radiant remains actives in the far south. The Delta Pavonids
are best seen just before morning twilight from tropical and Southern
Hemisphere sites. Unfortunately the moon will also be out during this
time reducing any activity seen. On Saturday morning the radiant will be
located near 20:00 -62. Radiant drift for the Delta Pavonids is 6.4
minutes eastward and 0.2 southward per day. Any shower members would be
swift with an entry velocity of 60 kilometers per second.
Finally, sporadic rates were still running higher than normal for
observers watching in areas free of light pollution. This week I would
expect evening watchers to see 4-5 sporadic meteors per hour while the
morning skies, with its lunar interference, will only be slightly better
at 6-7 meteors per hour.
At this time of year with low rates and no major showers currently
active it is entirely possible that you may be the only observer active
in the entire world at that particular moment concentrating on meteor
activity. If something unusual occurs it would then be up to you to
share it with others. Be sure to let us know what you see! Who knows
what surprises await the dedicated observer of March skies?
Clear Skies!
Robert Lunsford
AMS Visual Coordinator
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