Meteor Activity Outlook for July 2-8, 2011

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.

Meteor season finally gets going in July for the northern hemisphere. The first half of the month will be much like June. 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 Delta Aquariids.

During this period the moon reaches its first quarter phase on Friday July 8th. At this time the moon will lie ninety degrees east the sun and will set near 0100 local daylight time (LDT) for observers located n the mid-northern latitudes. This weekend the waxing crescent moon will set shortly after the end of evening twilight and will not cause problems observing meteors. The estimated total hourly rates for evening observers this week is near three as seen from the northern hemisphere and four as seen from the southern hemisphere. For morning observers the estimated total hourly rates should be near nine from the northern hemisphere and thirteen as seen from south of the equator. 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.

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 2/3. These positions do not change greatly day to day so the listed coordinates may be used during this entire period.

The following showers are expected to be active this week:

The wide Antihelion (ANT) radiant is now centered at 19:36 (294) -20. This area of the sky lies in northeastern Sagittarius, seven degrees east of the fourth magnitude star Pi Sagittarii. This radiant is best placed near 0200 LDT, when it lies on the meridian and is located highest in the sky. Due to the large size of this radiant, any meteor radiating from Sagittarius, Scutum, southern Aquila, western Capricornus, or Serpens Cauda could be a candidate for this shower. Rates at this time should be near two per hour as seen from the northern hemisphere and three per hour as seen from south of the equator. With an entry velocity of 30 km/sec., the average Antihelion meteor would be of medium-slow speed.

Studies by Sirko Molau and Juergen Rendtel of the IMO’s video data has revealed an active radiant located in Andromeda this time of year. The c-Andromedids (CAN) are active from July 4-16, with maximum activity occurring on the 12th. The radiant position is currently located at 01:32 (023) +45. This area of the sky lies in northeastern Andromeda, eight degrees northwest of the famous second magnitude double star Almach (Gamma Andromedae). This radiant is best placed during the last dark hour before dawn, when it lies highest above the horizon in a dark sky. Rates at this time should be less than one no matter your location. With an entry velocity of 59 km/sec., the average c-Andromedid meteor would be of swift speed.

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 two 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 three per hour during the evening hours. Locations between these two extremes would see activity between the listed figures. Morning 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.

Shower Name                 RA     DEC   Vel     Rates
                                         km/s   NH    SH
ANT Antihelions           19h 36m  -20    30     2     3
CAN c-Andromedids         01h 32m  +45    59    <1    <1

RA - Right Ascension
DEC - Declination
Vel - Velocity relative to Earth (in km per sec)
Rates - Rate of visible meteors per hour from a dark site
NH - Northern Hemisphere
SH - Southern Hemisphere

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

11 Responses to Meteor Activity Outlook for July 2-8, 2011

  1. Diane Chance says:

    I leave on South Dakota and last night 7/2/11-7/3/11 about 12:25am, while looking to the western sky, I observed a large bright reddish orange ball in the sky. It was very round and had no trail what so ever. However the ball on its left edge had a yellow cast. It was moving to the north and as it moved north it also moved down across the sky, It was gone from my view before I could get a camera to snap a picture. It has just boggled me all day and thought maybe someone else saw it and would know what it was. I have never seen anything like it in my life.

    • raftin says:

      Saw something very much as described from Lake Tahoe Nevada area on July 3 at about 11:20 PM Pacific Time. It seemed particularly thick or girthy, however I did see a trail opposed to the comment above. Had an orangish hue and I believe it was in the Eastern sky at about 45 degrees going from south to north. Probably biggest object I’ve ever seen fly by/hit the atmosphere. put other shooting stars to shame!

    • cARRIE says:

      7/5/11 Friend and I saw large bright orange fireball in sky, traveling in a easterly direction at approx. 10:15 p.m., and again at approx. 10:30 p.m. We live in Southfield, Michigan.

    • Joe says:

      7/2/2011 1:50 AM heading south rt 24 Massachusetts probably in Stoughton. Cloudy, rainy almost foggy night. Saw what looked like a plane on fire toward the south moving west to east and dropping down and out of site just before hitting the horizon. It was orange ball with a bit of a tail.

  2. Omaha Bob says:

    I was having a small gathering July 3rd, in the suburbs of Omaha, Nebraska. There were six of us that saw a large oval, orange, flying object 10:30 PM CST. There was debating about if it was a plane or not, but everyone concluded it was a large meteorite once the color just seemed to disappear. It vaguely had a tail for a short time. It was moving Northwest. Later on, a few others saw two more smaller orange objects going Northwest.

  3. Martha says:

    July 4, 2011 – I saw this while watching fireworks in this Oklahoma City. I saw a red glow with lighter outline moving South Southeast to North Northwest about 9:30 PM CST. Kept waiting for it to open up and make a noise. It never did. It just kept tracking. I’ve seen meteors before, higher in the sky lasting 1 to 3 seconds. This was slower moving and lasted over 20 seconds (ran through house to get husband) then ran out back. I couldn’t find it behind the tree line.

  4. amanda wilson says:

    Lansing Ks July 4th 10:50 pm myself and 3 others saw a Orange red ball moving east to west at a steady speed was in view maybe a minute or two from the back view once it went west it looked dimmer with faint whitish gray outline to it then it disappeared behind the trees, what was it we saw?

  5. Megan Baldwin says:

    Saw a sequence of fireballs lighting the Eastern sky from Issaquah, WA last night between 10:30PM-11:30PM Monday night, July 4.

  6. Chad Riddle says:

    On the nights of July 3rd and 4th, 2011—my wife and I observed several fireballs [perhaps 20 or more over the course of both nights. These objects were smaller than the sun or moon appears to the naked eye ~ but much larger than any fixed star as seen by the naked eye. We live in northern Missouri. I find it somewhat odd that these events were not reported in any major news outlet? These certainly were the most SPECTACULAR celestial events either of us have ever observed. These fireballs lasted for up to 1 minute or more before disintergating.

  7. Cindy Frankfort IL says:

    I saw the same thing on July 2 at 12:45 am i though it was a plane on fire in the sky
    so am not nut🙂 thank you do we have pic.

  8. Amber says:

    I am in Rapid City SD. I was trying to find others that saw these things and wishing I would have had a camera to video. On the 4th of July 2011 I was standing in my backyard on the phone with my mom and watching fireworks everywhere. I saw an orange/yellow ball moving slowly thru the sky from left to right. It was not falling or acting like any meteor I had ever seen. It lasted about 30 secs then it disappeared and RIGHT as it disappeared a second one appeared (there was a big house blocking view as to where they were originating so they would just suddenly come from behind the house into my view) and it followed the same path as the first one slowly. Once it disappeared in the exact same place as the first one a THIRD ball came following the path and did the same thing as the first 2 lights. It is the first time I can say that I’ve ever seen anything I truly could not explain. I was telling my mom on the phone what I was seeing but I was so caught up in the whole thing I never thought to run in the house and get a camera. In fact for a good while I kept doubting what I was seeing or even thinking it was some sort of firework. I wish someone would have caught it on video and put it on youtube. Someone else I know saw the same thing I did. So weird.

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