During this period the moon reaches its full phase on Sunday August 10th. At this time the moon is located opposite the sun and will be in the sky all night long. Later this week the waning gibbous moon will rise later in the evening allowing a brief period between dusk and moonrise to view under dark skies. The estimated total hourly meteor rates for evening observers this week is near 4 as seen from the northern hemisphere and 2 as seen from southern tropical latitudes. For morning observers the estimated total hourly rates should be near 17 for observers located in mid-northern latitudes and 13 for south tropical observers. 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 during this period will are lower than normal due to moonlight. Note that the hourly rates listed below are estimates as viewed from dark sky sites away from urban light sources. Observers viewing from urban areas will see less activity as only the brightest meteors will be visible from such locations.
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 August 9/10. 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 stores 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.
These sources of meteoric activity are expected to be active this week. Details of each shower will return next week when observing conditions are much more favorable for viewing meteor activity.
|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|
|Kappa Cygnids (KCG)||Aug 18||18:56 (284) +58||23||22:00||<1 – <1||II|
|Anthelions (ANT)||–||22:00 (330) -10||29||01:00||1 – 1||II|
|Theta Piscids (TPI)||Aug 20||22:56 (344) +01||39||02:00||<1 – <1||IV|
|Delta Aquariids (SDA)||Jul 30||23:24 (351) -13||42||03:00||2 – 5||I|
|Perseids (PER)||Aug 13||02:56 (044) +57||61||06:00||7 – 3||I|
|Eta Eridanids (ERI)||Aug 04||02:56 (044) -11||66||06:00||1 – 1||IV|
|Alpha Triangulids (ATR)||Aug 08||03:08 (047) +37||67||06:00||1 – <1||IV|