During this period the moon will wane from it’s nearly full phase down to almost half-illuminated. This weekend the moon will rise shortly after dusk and will rise approximately 45 minutes later each night. Although meteor activity is strong this time of year the bright moon will obscure all but the brighter meteors. The estimated total hourly meteor rates for evening observers this week is near 3 as seen from mid-northern latitudes and also 3 for those viewing from subtropical southern latitudes (25S). For morning observers the estimated total hourly rates should be near 14 for those viewing from mid-northern latitudes and also 14 for those viewing from subtropical southern latitudes (25S). 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 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 brighter 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 July 28/29. 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 near 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 far 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 stream will continue next week when the moon will not be such a factor.
|SHOWER||DATE OF MAXIMUM ACTIVITY||CELESTIAL POSITION||ENTRY VELOCITY||CULMINATION||HOURLY RATE||CLASS|
|RA (RA in Deg.) DEC||Km/Sec||Local Summer Time||North-South|
|alpha Capricornids (CAP)||Jul 27||20:20 (305) -10||22||01:00||1 – 1||II|
|Anthelions (ANT)||–||21:12 (318) -16||30||02:00||1 – 2||III|
|Northern delta Aquariids (NDA)||Aug 14||21:44 (333) -04||38||03:00||<1 – <1||IV|
|Southern Delta Aquariids (SDA)||Jul 30||22:40 (340) -17||41||04:00||3 – 4||I|
|Piscis Austrinids (PAU)||Aug 08||22:52 (343) -24||44||04:00||<1 – <1||II|
|July Pegasids (JPE)||Jul 10||00:16 (004) +15||68||06:00||<1 – <1||IV|
|Perseids (PER)||Aug 13||01:48 (027) +54||59||06:00||3 – 2||I|
|49 Andromedids (FAN)||Jul 21||02:16 (034) +51||60||07:00||<1 – <1||IV|
|eta Eridanids (ERI)||Aug 11||02:12 (033) -16||65||07:00||<1 – <1||IV|
|phi Piscids (PPS)||Jul 05||02:40 (040) +34||66||08:00||<1 – <1||IV|
|psi Cassiopeiids (PCA)||Jul 22||03:08 (047) +76||42||08:00||<1 – <1||IV|
|July chi Arietids (JXA)||Jul 13||03:24 (051) +14||69||08:00||<1 – <1||IV|