Meteor Activity Outlook for August 28-September 3, 2010

The Meteor Activity Outlook is a weekly summary of expected meteor activity written by Robert Lunsford, Operations Manager of the American Meteor Society and contributor to this blog. The original unedited version of this week’s Meteor Activity Outlook can be found at the American Meteor Society’s site.

September offers longer nights in the northern hemisphere that tend to be less hazy than those experienced in mid-summer. In the sky, no major showers are visible from either hemisphere but the northern hemisphere enjoys the advantage of higher sporadic rates. Most of the shower activity this month is produced from the Perseus-Aurigid complex active this time of year. These showers rarely produce more than five meteors per hour but still manage to produce most of the shower activity seen this month. Unfortunately the Perseus-Aurigid complex lies too low in the northern sky for southern hemisphere observers to view very well. Video studies have shown that the Southern Taurids are visible as early as September 7th therefore after this date the Antihelion radiant will no longer be listed until the Taurid showers end in December. The Antihelion meteors are still active but their radiant is superimposed upon that of the more numerous Taurids, therefore it is impossible to properly separate these meteors. Observers in the southern hemisphere suffer from some of their lowest rates of the year this month. The Southern Taurid radiant is not too badly placed so observers south can expect to see a little of this activity this month.

During this period the moon reaches its last quarter phase on Wednesday September 1st. At this time the moon will be located ninety degrees west of the sun and will rise near 0100 local daylight time (LDT) for locations in the mid-northern latitudes of the northern hemisphere. This weekend the waning gibbous moon will rise during the late evening hours and remain in the sky the remainder of the night. Meteor observations are difficult under such circumstances unless your sky is transparent. The estimated total hourly rates for evening observers this week is ~3 from the northern hemisphere and ~2 from the southern hemisphere. For morning observers the estimated total hourly rates should be ~12 from the northern hemisphere and ~8 as seen from the southern hemisphere. 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. During this period, moonlight reduces activity seen during the morning hours.

The radiant positions and rates listed below are exact for Saturday night/Sunday morning August 28/29. These positions do not change greatly day to day so the listed coordinates may be used during this entire period.

As seen from the mid-northern hemisphere (45N) one would expect to see approximately five 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 fourteen 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 slightly reduced due to moonlight.

The following showers are expected to be active this week:

August Draconids (AUD)

The last few remnants from the August Draconids (AUD) may be seen this weekend. The radiant is currently located at 18:44 (281) +63. This position lies in southern Draco, ten degrees east of the second magnitude star Eltanin (Gamma Draconis). With an entry velocity of 23 km/sec. most of these meteors will appear to move slowly. The radiant is best placed near 2200 Local Daylight Time (10pm LDT) when it lies highest in the sky. Due to its high northern declination this shower is not well seen from the southern hemisphere.

Antihelions (ANT)

The wide Antihelion (ANT) radiant is now centered at 23:12 (348) -03. This area of the sky lies in western Pisces, three degrees north of the fourth magnitude star Phi Aquarii. 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 eastern Aquarius, southern Pegasus, western Pisces, or western Cetus could be a candidate for this shower. Rates at this time should be ~2 per hour no matter your location. With an entry velocity of 30 km/sec., the average Antihelion meteor would be of medium-slow speed.

Alpha Aurigids (AUR)

The Alpha Aurigids (AUR) is the first radiant of the Perseus-Aurigid complex to become active. Maximum occurs on September 1, so rates this weekend will be very low. Even at maximum with a last quarter moon in the sky, rates will most likely not exceed one shower member per hour. The radiant position at maximum is 06:04 (091) +36. This position lies in eastern Auriga only one degree southeast of the third magnitude star Theta Aurigae. This is different than the old position which was close to Capella (Alpha Aurigae). Video results from the 2007 outburst of this shower showed that a majority of the activity came from the radiant near Theta Aurigae. The radiant is best placed near 0500 LDT, when it lies highest in a dark sky. With an entry velocity of 67 km/sec., most activity from this radiant would be swift. Activity can be seen, if it occurs, from the southern tropic regions during the last few hours before dawn.

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
AUG August Draconids     18h 44m  +63    23    <1    <1
ANT Antihelions          23h 12m  -03    30     2     3
AUR Alpha Aurigids       06h 04m  +36    67     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

9 Responses to Meteor Activity Outlook for August 28-September 3, 2010

  1. Steve Porter says:

    Just saw something like a shooting star, but much bigger and brighter. More like a fireball. Western lower horizon–I observed from Long Beach. It occurred about 10:15pm Tuesday night. Have you heard anything about it?

    • Cooper says:

      I live in Indio, CA and was sitting in the backyard about 10:15 and saw something shooting across the sky. It was a fireball, I guess, with a bright lighted tail. I have never seen anything so big out here and it seemed so close. Wow, glad you saw it too.

  2. Shanna says:

    My daughter was sitting outside, (near Knotts) and saw it too. She said she has never seen anything like it, and it kind of freaked her out.. Its good to know she didn’t imagine it . : )

  3. Jessica says:

    I saw it also… I’m in Garden Grove, Ca. I’ve been searching online since then to see if anyone else saw it. I saw like a blue/green ball with a bright tail. I was in my car outside of my sisters apartment, on the phone with her figuring out where to park and saw something in the corner of my eye. I thought it was a firework at first but when I turned my head, it quickly shot across the sky and at an angle. If anyone finds any info about it, please let me know. I’ve seen a few weird things up in the sky before but have never been able to figure out what they were and I’ve always been interested in stuff like this.

  4. Chris says:

    About 1:25 am on 9/1/2010 Wednesday I observed a bright flash of light. I had put my dog outside and my back yard was lit up for about 2 seconds. I did not see what it was first hand. This was in the San Francisco bay area. The light appeared to be coming from the north west. It was not a police helicopter since you can obviously hear a helicopter.
    I will check the recordings from my security cameras tonight so I can show my wife.

  5. Carl Hergenrother says:

    Everybody,

    Thanks for calling attention to last night’s event. Based on your observations, there is no doubt that a bright fireball happened over southern CA around 10:15 pm. Chris mentioned another possible fireball over northern CA at 1:25 am. If it is also a fireball, it was not the same object that caused the southern CA event though they may be from the same meteor shower (that’s unlikely this time of the year).

    If you’re willing, please submit a fireball report to the American Meteor Society at
    http://www.amsmeteors.org/fireball/report.html

    Reports are usually posted on the AMS website within a few days at
    http://www.amsmeteors.org/fireball/fireball_log2010.htm

    As for exactly what you saw, it was probably a small asteroid (no larger than your fist) burning up as it moved through the Earth’s upper atmosphere at 8 to 24 miles per second. Though it may have appeared to be close to you, it was actually located at an altitude of 25 to 50 miles up.

    – Carl

  6. Carolyn says:

    After leaving the Dodger game Tuesday night, my boyfriend saw the same thing as we drove onto the freeway. I thought he was seeing things but as we got closer to home (Fresno, CA) I saw one as well. We were actually in Kingsburg, CA when I witnessed it. It was big, bluish white and something I’ve never seen in my life! Pretty awesome and it too was on the northwest side of us.

  7. Kristen says:

    We saw it, too. Does anyone know what it was caused from or where it landed?

  8. gerry says:

    Large streaking object spotted over southeast skies in north-central florida, @ 10:40 pm September 2. Arced from west to east, appeared to break apart before disappearing.

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