During this period the moon reaches its full phase on Tuesday July 19th. At this time the moon will lie opposite the sun and will lie above the horizon all night long. With the bright lunar glare present most of the night this week, this will be the least favorable time to try and view meteor activity this month. The estimated total hourly meteor rates for evening observers this week is near 2 no matter your location. For morning observers the estimated total hourly rates should be near 16 for those located at mid-northern latitudes and 13 for observers located in tropical southern locations (25S). Rates are reduced this week due to moonlight. 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. 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 July 16/17. 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 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 on each source will continue next week when the glare from the moon will not be so intrusive.
|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 26||19:44 (300) -13||22||00:00||1 – 1||II|
|Anthelions (ANT)||–||20:28 (307) -18||30||01:00||1 – 2||II|
|Sigma Capricornids (SCA)||Jun 27||21:30 (323) -04||42||02:00||<1 – <1||IV|
|Delta Aquariids (SDA)||Jul 28||22:04 (331) -20||42||03:00||<1 – <1||I|
|Piscis Austrinids (PAU)||Jul 27||22:12 (333) -35||35||03:00||<1 – <1||IV|
|July Pegasids (JPE)||Jul 10||23:34 (354) +13||68||05:00||1 – 1||IV|
|Perseids (PER)||Aug 12||00:43 (011) +51||61||06:00||3 – 1||I|
|Phi Piscids (PPS)||Jul 02||01:54 (029) +34||68||07:00||<1 – <1||IV|
|Psi Cassiopeiids (PSA)||Jul 16||01:56 (029) +71||46||07:00||1 – <1||IV|
|c-Andromedids (CAN)||Jul 12||02:34 (039) +50||60||08:00||1 – <1||IV|