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Meteor season finally gets going in July for the northern hemisphere. The first half of the month will be much like June with predominately slow rates. After the 15th though, both sporadic and shower rates increase significantly. For observers in the southern hemisphere, sporadic rates will be falling but the overall activity will increase with the arrival of the Southern delta Aquariids during the last week of the month.

During this period the moon reaches its new phase on Tuesday July 2nd. On that date the moon is located near the sun and is invisible at night. This weekend the waning crescent moon will rise during the late morning hours but will not cause any problems for viewing meteor activity as long as you keep it out of your field of view. The estimated total hourly meteor rates for evening observers this week is near 3 for those viewing from the northern hemisphere and 4 for those located south of the equator. For morning observers the estimated total hourly rates should be near 6 as seen from mid-northern latitudes (45N) and 7 as seen from tropical southern locations (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. 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 June 29/30. 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.

The alpha Capricornids (CAP) are active from July 3 through August 11 with maximum activity occurring during the last week of July. The broad maximum occurs anywhere from July 25 to the 30th with visual rates usually around 3 per hour. The radiant is currently located at 18:23 (276) -17, which places it in northern Sagittarius, 2 degrees south of the dim star known as gamma Scuti. This radiant is best placed near 01:00 local summer time (LST), when it lies on the meridian and is located highest in the sky. Hourly rates at this time should be less than 1 no matter your location. With an entry velocity of 22 km/sec., the average alpha Cap meteor would be of slow velocity.

The center of the large Anthelion (ANT) radiant is currently located at 19:24 (291) -22. This position lies in eastern Sagittarius, 1 degree east of the bright planet Saturn. This area of the sky is best placed near 02:00 LST when it lies highest above the southern horizon. Due to the large size of this radiant, anthelion activity may also appear from Scutum as well as Sagittarius. Rates at this time should be near 2 per hour as seen from mid-northern latitudes (45 N) and 3 per hour as seen from the southern tropics (S 25). With an entry velocity of 30 km/sec., the average anthelion meteor would be of slow velocity.

The Northern June Aquilids (NZC) are active from a radiant located at 20:28 (307) -06. This area of the sky is located in southeastern Aquila, 6 degrees northeast of the 3rd magnitude star known as Algiedi Prima (alpha1 Capricorni). This radiant is best placed near 03:00 LST, when it lies on the meridian and is located highest in the sky. Hourly rates at this time should be near 2 no matter your location. With an entry velocity of 38 km/sec., the average meteor from this source would be of medium-slow velocity. An interesting fact about this source is that it may be related to the Northern delta Aquariids of August. Where and when this source ends coincides with the start and position of the Northern delta Aquariids.

The Southern June Aquilids (SZC) were discovered by G. Gartrell and W. G. Elford, in their study of Southern Hemisphere meteor streams. This stream is active from June 9 through July 17 with maximum activity occurring on July 6. The radiant is currently located at 20:52 (313) -29. This area of the sky is actually located in northern Microscopium, 3 degrees south of the 4th magnitude star known as omega Capricornii. This radiant is best placed near 0400 LST, when it lies on the meridian and is located highest in the sky. Hourly rates at this time are expected to be less than 1 as seen from the northern hemisphere and 1 as seen from south of the equator. With an entry velocity of 39 km/sec., the average meteor from this source would be of medium-slow velocity. This source is synonymous with the Microscopiids.

The last of the beta Equulids (BEQ) are expected this weekend. The radiant position currently lies at 21:07 (316) +04. This area of the sky lies in southern Equuleus, 2 degrees southwest of the 4th magnitude star known as Kitalphar (alpha Equulei). This radiant is best placed near 0400 LDST, when it lies on the meridian and is located highest in the sky. Hourly rates are expected to be less than 1, no matter your location. With an entry velocity of 33 kilometers per second, a majority of these meteors will appear to move with medium-slow velocities.

The epsilon Pegasids (EPG) were discovered by Dr. Peter Brown and associates using data from the Canadian Meteor Orbit Radar (CMOR) installation. These meteors are active from July 03-23 with maximum activity occurring on July 11th. The radiant position currently lies at 21:24 (321) +09. This area of the sky lies in eastern Equuleus, 2 degrees east of the 4th magnitude star known as delta Equulei. These meteors are best seen near 0400 LST when the radiant lies highest in the sky. Hourly rates are expected to be less than 1 no matter your location. With an entry velocity of 28 kilometers per second, a majority of these meteors will appear to move with medium-slow velocities.

The July Pegasids (JPE) have been noticed for some time now but have had a checkered history. It has been added, dropped, and then re-added to several radiant lists. Video studies within the past 10 years have positively identified this source as an active radiant during the entire month of July. Maximum activity occurs on July 10th. The radiant is currently located at 22:39 (340) +09. This area of the sky is located in southern Pegasus, 2 degrees south of the 3rd magnitude star known as Homan (zeta Pegasi). This radiant is best placed near 0500 LST, when it lies on the meridian and is located highest in the sky. Rates are expected to be less 1 per hour this week no matter your location. With an entry velocity of 68 km/sec., the average meteor from this source would be of swift velocity.

The phi Piscids (PPS) were another discovery by Dr. Peter Brown and associates using data from the Canadian Meteor Orbit Radar (CMOR) installation. These meteors are active from June 8-August 02 with maximum activity occurring on July 5th. The radiant position currently lies at 00:49 (012) +23. This area of the sky lies in southern Andromeda, 1 degree west of the 4th magnitude star known as eta Andromedae. These meteors are best seen near during the last dark hour of the night when the radiant lies highest in a dark sky. Current rates should be near 2 per hour as seen from the northern hemisphere and 1 as seen from south of the equator. With an entry velocity of 67 kilometers per second, a majority of these meteors will appear to move with swift velocities.

The c-Andromedids (CAN) were discovered by Sirko Molau and Juergen Rendtel using video data from the IMO network. Activity from this source is seen from June 26 through July 27 with maximum activity occurring on July 9. The radiant currently lies at 01:14 (018) +45, which places it in northern Andromeda, almost 3 degrees south of the 4th magnitude star known as phi Andromedae. This area of the sky is best seen during the last dark hour before dawn when the radiant lies highest in a dark sky. Observers in the northern hemisphere are better situated to view this activity as the radiant rises much higher in the sky before dawn compared to southern latitudes. Current rates would be near 1 per hour for observers in the northern hemisphere and less than 1 as seen from south of the equator. With an entry velocity of 58 km/sec., the average meteor from this source would be of swift velocity.

The July chi Arietids (JXA) were discovered by two investigating teams in Europe using video data from European video Meteor Network Database (EDMOND), SonotaCo, 2013; and CMN, 2013. Activity from this stream is seen from July 2 through August 1 with maximum activity occurring on July 13. The radiant currently lies at 01:32 (023) +05, which places it in southeastern Pisces, 1 degree south of the faint star known as mu Piscium. This area of the sky is best seen during the last dark hour before dawn when the radiant lies highest in a dark sky. Current rates are expected to be less than 1 per hour during this period. With an entry velocity of 69 km/sec., the average meteor from this source would be of swift velocity.

As seen from mid-northern hemisphere (45N), morning rates would be near 7 per hour as seen from rural observing sites and 2 per hour during the evening hours. As seen from the tropical southern latitudes (25S), one would expect to see approximately 8 sporadic meteors per hour during the last hour before dawn as seen from rural observing sites. Evening rates would be near 3 per hour. Locations between these two extremes would see activity between the listed figures.

The list below offers the information from above in tabular form. Rates and positions are exact for Saturday night/Sunday morning except where noted in the shower descriptions.
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 18:23 (276) -17 22 01:00 <1 - <1 II
Anthelion (ANT) - 19:24 (291) -22 30 02:00 2 - 3 II
Northern June Aquilids (NZC) Jul 03 20:28 (307) -06 41 03:00 2 - 2 IV
Southern June Aquilids (SZC) Jul 06 20:52 (313) -29 39 04:00 <1 - 1 IV
beta Equulids (BEQ Jun 15 21:07 (316) +04 33 04:00 <1 - <1 IV
epsilon Pegasids (EPG) Jul 11 21:24 (321) +09 28 04:00 <1 - <1 IV
July Pegasids (JPE) Jul 10 22:39 (340) +09 68 05:00 <1 - <1 IV
phi Piscids (PPS) Jul 05 00:49 (012) +23 67 07:00 2 - 1 IV
c-Andromedids (CAN) Jul 09 01:14 (018) +45 58 08:00 <1 - <1 IV
July chi Arietids (JXA) Jul 13 01:32 (023) +05 69 08:00 <1 - <1
Zgodnie z:
Robert Lunsford


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