Meteor Activity Outlook for April 7-13, 2012
April 7, 2012 3 Comments
The following is a slightly edited version of Bob Lunsford’s excellent weekly summary of meteor activity. The original version can be found at the American Meteor Society’s site.
Meteor activity picks up a bit during April as two major showers are active during the month. The first of these, the Lyrids, are active from the 16th through the 25th, with a pronounced maximum on the 22nd. The Eta Aquariids start appearing near the 28th and reach maximum activity during the first week in May. Sporadic rates are low but steady as seen from the mid-northern hemisphere (45 N). Sporadic rates seen from the mid-southern hemisphere (45 S) rise this month toward a maximum in July.
During this period the moon reaches its last quarter phase on Friday April 13th. At that time the moon will be located ninety degrees west of the sun and will rise near 0200 daylight saving time (DST) for observers situated in the mid-northern latitudes. This weekend the waning gibbous moon will rise during the early evening hours, effectively ruining the sky for nearly the entire night. This week is the worst time to try and view meteor activity during the month. Conditions will improve when the moon reaches its last quarter phase and continues to wane toward new. The estimated total hourly rates for evening observers this week is near one for observers in the northern hemisphere and two for those south of the equator. For morning observers the estimated total hourly rates should be near three as seen from mid-northern latitudes and six from mid-southern latitudes. The actual rates will also depend on factors such as personal light and motion perception, local weather conditions, alertness and experience in watching meteor activity. Rates are reduced during this period due to severe moonlight.
The radiant (the area of the sky where meteors appear to shoot from) positions and rates listed below are exact for Saturday night/Sunday morning April 7/8. These positions do not change greatly day to day so the listed coordinates may be used during this entire period.
The list below presents a condensed version of the expected activity this week.
Rates and positions are exact for Saturday night/Sunday morning.
Antihelion (ANT) – 14:04 (211) -12 Velocity 30km/sec
Northern Hemisphere – 1 per hr Southern Hemisphere – 1 per hour
Zeta Cygnids (ZCY) 20:04 (301) +41 Velocity 44km/sec
Northern Hemisphere – <1 per hr Southern Hemisphere – <1 per hour