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. Most star atlases (available at science sores and planetariums) will provide maps with grid lines of the celestial coordinates so that you may find out exactly where these positions are located in the sky. A planisphere or computer planetarium program is also useful in showing the sky at any time of night on any date of the year. Activity from each radiant is best seen when it is positioned highest in the sky, either due north or south along the meridian, depending on your latitude. It must be remembered that meteor activity is rarely seen at the radiant position. Rather they shoot outwards from the radiant so it is best to center your field of view so that the radiant lies at the edge and not the center. Viewing there will allow you to easily trace the path of each meteor back to the radiant (if it is a shower member) or in another direction if it is a sporadic. Meteor activity is not seen from radiants that are located below the horizon. The positions below are listed in a west to east manner in order of right ascension (celestial longitude). The positions listed first are located further west therefore are accessible earlier in the night while those listed further down the list rise later in the night.
The table below presents a condensed version of the expected activity this week. Rates and positions are exact for Saturday night/Sunday morning. Detailed descriptions of each shower will continue next week when moonlight conditions improve.
|SHOWER||DATE OF MAXIMUM ACTIVITY||CELESTIAL POSITION||ENTRY VELOCITY||CULMINATION||HOURLY RATE||CLASS|
|RA (RA in Deg.) DEC||Km/Sec||Local Daylight Time||North-South|
|Antihelions (ANT)||–||14:04 (211) -12||30||02:00||1 – 1||II|
|Zeta Cygnids (ZCY)||Apr 05||20:04 (301) +41||44||08:00||<1 – <1||IV|