During August observers in the northern hemisphere continue to see a rise in the meteor activity, especially near August 12, when the Perseids reach maximum strength. This peak is somewhat modified this year by the bright gibbous moon that will be present during the Perseid maximum. Observers south of the equator are seeing their rates plummet as the Perseids have little effect in producing activity from the far southern latitudes.
This week the moon will reach its full phase on Wednesday August 9th. This weekend the waxing gibbous moon will set during the early morning hours, allowing a small window of opportunity between moonset and the start of morning twilight, to observe in dark skies. As the week progresses, the moon will be in the sky most of the night, interfering with observing. The estimated total hourly rates for evening observers this week is near two no matter your location. For morning observers the estimated total hourly rates should be near twenty five for those in the northern hemisphere and eighteen for those south of the equator. These rates assume that you are watching from rural areas away from all sources of light pollution. 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. Evening rates are reduced due to moonlight.
The radiant positions listed below are exact for Saturday night/Sunday morning August 5/6. 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. 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 Kappa Cygnids (KCG) are active from a wide radiant centered at 18:52 (283) +58. This position is located in southern Draco, four degrees northwest of the fourth magnitude star Kappa Cygni. Current rates would be near one shower member per hour. A large percentage of these meteors are bright, often fireball class meteors with brilliant colors. With an entry velocity of 25 km/sec. most of these meteors will appear to travel slower than average. The radiant is best placed near 2300 Local Daylight Time (11pm LDT) when it lies nearly overhead for much of the Northern Hemisphere. Due to its high northern declination this activity is not well seen from the Southern Hemisphere.
The Alpha Capricornids (CAP) are active from a wide radiant centered at 20:56 (314) -08. This area of the sky is centered in southwestern Aquarius, just one degree northeast of the faint star Mu Aquarii. The radiant is best placed near 0100 local daylight time, when it lies highest in the sky. Current rates would be near one per hour, no matter your location. With an entry velocity of 23 km/sec., most activity from this radiant would be slow. This radiant is well seen except for far northern latitudes where it remains twilight all night long and the radiant does not rise as high into their sky. The Alpha Caps are also known for producing impressive fireballs.
The Antihelion (ANT) radiant is now centered at 21:44 (326) -12. This area of the sky is centered in eastern Capricornus, three degrees north of the third faint magnitude star Delta Capricornii. This radiant is best placed near 0200 local daylight time when it lies on the meridian and is highest in the sky. Rates at this time should be near one per hour for those north of the equator and two per hour south of the equator. With an entry velocity of 30 km/sec., the average Antihelion meteor would be of medium-slow speed. Please note that commencing in 2007; the International Meteor Organization will suggest that visual observers include the North Delta Aquarids and both branches of the Iota Aquarids as Antihelions.
The Southern Delta Aquarids (SDA) reached maximum activity on July 28, with rates between 10 and 20, depending on your latitude. The radiant is currently located at 23:04 (346) -14. This position lies in southern Aquarius, three degrees northeast of the third magnitude star Delta Aquarii.
The radiant is best placed near 0300 local daylight time, when it lies highest in the sky. Observers near 20 degrees south latitude are most favored with longer nights and the radiant passing through the zenith. With an entry velocity of 41 km/sec., most activity from this radiant would be of
average velocities. These meteors tend to be faint so the current rates with all the moonlight present would only be near one shower member per hour, no matter your location.
The Pisces Austrinids (PAU) also peaked on July 28 with a predicted ZHR of five. Current rates, with all the moonlight present, would be less than one per hour regardless of your location. The radiant is currently located at 23:16 (349) -27. This area of the sky lies four degrees northeast of the bright star Fomalhaut (Alpha Piscis Austrini). These meteors are best seen near 0300 LDT, when the radiant lies highest above the horizon. These meteors are of average velocity, slower than the Aquarids but faster than the Alpha Caps and the antihelion meteors.
Perseid (PER) activity is now near ten per hour, as seen from the northern hemisphere. These rates will increase sharply as we approach the peak on the morning of August 12. The current radiant position lies at 02:32 (038) +56, which is located in extreme northwestern Perseus, three degrees west of the fourth magnitude star Eta Persei. The radiant is well placed for those in the Northern Hemisphere during the last few hours before dawn. Due to the high northern declination (celestial latitude) of the radiant, rates seen
from the Southern Hemisphere are very low when compared to those seen north of the equator. At 59 km/sec., Perseid meteors are swift, often exhibiting persistent trains.
Sporadic rates continue to climb for observers located in the northern hemisphere. One would expect to see perhaps twelve random meteors during the last hour before dawn from rural observing sites. During the first dark hour
after the end of evening twilight, perhaps two random meteors can be seen per hour. Sporadic rates increase as the night progresses so rates seen near midnight would be near seven per hour. Sporadic rates seen from the southern
hemisphere are now falling rapidly. One would see approximately eleven random meteors per hour during the last hour before dawn and two per hour during the first dark hour after the end of evening twilight. Rates near midnight would be near six per hour. Evening rates are reduced due to