Meteor Activity Outlook for June 23-29, 2012

The following is a slightly edited version of Bob Lunsford’s excellent weekly summary of meteor activity. The original version can be found at the American Meteor Society’s site.

June is another slow month for meteor activity. There are no major showers active in June and only the Antihelion source can be counted on for continuous activity. Even the Antihelion radiant is located so far south this time of year that rates rarely exceed one per hour as seen from the mid-northern hemisphere (45 N) . Sporadic rates have reached their nadir and are now slowly rising as seen from the northern hemisphere. Sporadic rates seen from the mid-southern hemisphere (45 S) see a slow decline this month and a more moderate decline in July.

During this period the moon reaches its first quarter phase on Tuesday the 26th. At this time the moon will be located ninety degrees west of the sun and will set between midnight and 0100 for observers located in mid-northern latitudes. This weekend the waxing crescent moon will set during the late evening hours and will be long gone by the time the more active morning hours arrive. The estimated total hourly meteor rates for evening observers this week is near two for observers in the northern hemisphere and three for those south of the equator. For morning observers the estimated total hourly rates should be near ten as seen from mid-northern latitudes and fourteen from mid-southern latitudes. 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 (the area of the sky where meteors appear to shoot from) positions and rates listed below are exact for Saturday night/Sunday morning June 23/24. These positions do not change greatly day to day so the listed coordinates may be used during this entire period.

The following radiant is expected to be active this week:

A few June Bootids (JBO) may be seen during the evening hours this week radiating from a position near 14:56 (224) +48. This area of the sky lies in northern Bootes, seven degrees north of the fourth magnitude star Beta Bootis. This radiant is best placed as soon as it becomes dark. Hourly rates at this time are expected be less than one for those located in the northern hemisphere and near zero for observers south of the equator. With an entry velocity of 18 km/sec., the average June Bootid meteor would be of very slow speed.

Studies by Sirko Molau and Juergen Rendtel of the IMO’s video data has revealed an active radiant located in Ophiuchus this time of year. The f-Ophiuchids (FOP) are only active from June 27th through July 1, with maximum activity occurring on June 29th. The radiant position at maximum is located at 17:46 (266) +09. This area of the sky lies in northern Ophiuchus, four degrees southeast of the second magnitude star Ras Alhague (Alpha Ophiuchi). This radiant is best placed near 0100 local daylight time (LDT), when it lies on the meridian and is located highest in the sky. Rates at this time are expected to be less than one no matter your location. With an entry velocity of 21 km/sec., the average f-Ophiuchid meteor would be of slow speed.

The large Antihelion (ANT) radiant is currently located at 19:00 (285) -22. This position lies in central Sagittarius, near the group of third and fourth magnitude stars known as  Xi, Omicron and Pi Sagittarii. Due to the large size of this radiant, Antihelion activity may also appear from eastern Scorpius, southeastern Ophiuchus, Serpens Cauda, Corona Australis, southern Aquila, western Capricornus, and Scutum as well as Sagittarius. This radiant is best placed near 0200 LDT, when it lies on the meridian and is located highest in the sky. Rates at this time should be near two per hour as seen from the northern hemisphere and three as seen from south of the equator. With an entry velocity of 30 km/sec., the average Antihelion meteor would be of slow velocity.

Another active radiant in Pisces has been found by Sirko Molau and Juergen Rendtel using the IMO’s video data. The Delta Piscids (DPI) are only active from June 20th through the 24th with maximum activity occurring on the 23th. The radiant position at maximum is located at 00:44 (011) +06. This area of the sky lies in south-central Pisces, just southwest of the fourth magnitude star Delta Piscium. This radiant is best placed just before dawn when the radiant lies highest in a dark sky. Rates, even at maximum activity, are expected to be less than one per hour no matter your location. With an entry velocity of 71 km/sec., the average delta Piscid meteor would be swift.

As seen from the mid-northern hemisphere (45N) one would expect to see approximately seven sporadic meteors per hour during the last hour before dawn as seen from rural observing sites. Evening rates would be near one per hour. As seen from the mid-southern hemisphere (45S), morning rates would be near ten per hour as seen from rural observing sites and two per hour during the evening hours. Locations between these two extremes would see activity between the listed figures. Evening rates are reduced due to moonlight.

The list below presents a condensed version of the expected activity this week.
Rates and positions are exact for Saturday night/Sunday morning unless the showers are of short duration. In that case the position on the night of maximum activity is listed.

June Bootids (JBO) – 14:56 (224) +48   Velocity 18km/sec
Northern Hemisphere – <1 per hr   Southern Hemisphere – <1 per hour

f-Ophiuchids (FOP) – 17:46 (266) +09   Velocity 21km/sec
Northern Hemisphere – <1 per hr   Southern Hemisphere – <1 per hour

Antihelions (ANT) – 19:00 (285) -22   Velocity 30km/sec
Northern Hemisphere – 2 per hr Southern Hemisphere – 3 per hour

Delta Piscids (DPI) – 00:44 (011) +06 Velocity 71km/sec
Northern Hemisphere – <1 per hr Southern Hemisphere – <1 per hour

Clear Skies!
Robert Lunsford
American Meteor Society

 

About Carl Hergenrother
I am a professional astronomer specializing in the study of comets, asteroids and meteors. This blog will focus on my professional and amateur work in this field

5 Responses to Meteor Activity Outlook for June 23-29, 2012

  1. Patricia Akee says:

    That’s not true! Last night my friends & I saw a large bright falling star (fireball?) streak across the sky… not as fast as normal falling stars – this one took it’s time! I have been trying to find a news article to verify what it was, but I can’t find anything… only a link to a webiste in America where a man saw a fireball.. could it be one and the same?

    • Robert says:

      I can confirm your perception

    • Brian says:

      I also saw the same bright fireball. I live in Perry georgia and saw it around 11 PM but I cannot be sure of the time. I have been searching but am amazed that there is notghing out there on hte web.

  2. Robert says:

    Yes I have also seen this Bright ball falling relaxed to earth! It was glowing almost itil the surface of the earth. short before (near impact) it vaporizes! It was a real bright piece of rock! We saw this in vienna at around 23:00 CET! Verry impressive!

  3. JohnVeritas says:

    Tonight (23.06.2012 04.48 at midnight gmt+2) i saw that Bright ball too that was amazing..!

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