(meteorobs) Meteor Observations from California August 11, 2004

Robert Lunsford lunro.imo.usa at cox.net
Wed Aug 11 11:34:52 EDT 2004


I just returned from a very enjoyable session on the western slopes 
of Mt. Laguna. The air was clear and warm, no need for any 
covering whatsoever. There was only one encounter with a flying
bug during the entire four hours. The sky was clear nearly all the 
way to the coast allowing some light pollution in the western sky.
The moon rose over the hills in the east at 10:41 UT (3:41 PST).
The sky was so transparent I lost only a tenth of a magnitude
after moonrise. When the moon was covered with my hand, I
could still follow the Milky Way to the Perseus/Auriga border, 
some 20 degrees from the moon. Venus was also a nice sight 
10 degrees below the crescent moon.

Meteor activity was impressive the entire session. There was a dip
in activity during the third hour, probably due to fatigue. There were
several minutes during the night that produced five or more meteors.
There was once instance when two Perseid meteors appeared 
simulteanously. The Perseids were brighter than expected. 19 of the 
127 Perseids were negative magnitudes, peaking with a -7 fireball 
that shot downward toward the northeastern horizon. The train on 
that one lasted 17 seconds. The percentage of trains for the brighter 
Perseids seemed less than normal. Many of  these were appearing 
near the radiant therefore displaying a slower angular velocity. 
While a great majority of the Perseids appeared white, there were 
several  blue and yellow Perseids. The most outstanding Perseids
appeared a distinct coppery orange color. These appeared a bit 
less often than the blue and yellow Perseids.

Since I was facing north it was impossible to properly classify
the radiants in Aquarius. I simply called all of these meteors
Antihelions. I was surprised I saw no activity from the Kappa
Cygnid radiant. I usually see a few of these slow meteors during
my Perseid sessions. A few of the Northen Apex meteors could 
have accidently been called Perseids. The meteors from the 
Southern Apex were far easier to distinguish.

This was a very satisfactory night and I look forward a a six hour
session tonight for the maximum. Hopefully I can get some rest 
before then!

August 11, 2004

0758-0900 UT  1.03  6.64   5 ANT   25  PER  1 NPX   0 SPX
                                            11 SPO  42 TOTAL

0900-1000 UT  1.00  6.59   3 ANT   36  PER  0 NPX   2 SPX
                                            11 SPO  52 TOTAL

1000-1100 UT  1.00  6.58   3 ANT   30  PER  0 NPX   0 SPX
                                             4 SPO   37 TOTAL

1100-1200 UT  1.00  6.46   1 ANT   36  PER  2 NPX   2 SPX
                                             7 SPO   48 TOTAL

TOTALS:          4.03  6.57   12 ANT  127  PER  3 NPX  4 SPX
                                            33 SPO  179 TOTAL

The first column gives the period watched stated in Universal Time (UT)
which is PDT + 7 hours. The second column gives the percent of that
particular hour actually spent observing the sky. The third column gives 
the average limiting magnitude estimated during each period. The last 
several columns list the activity seen during each period. I was facing 
north at an altitude of 40 degrees during the entire session. No breaks 
were taken.  ANT = Antihelion radiant, PER = Perseids, NPX = 
Northern Apex, SPX = Southern Apex and SPO = Sporadics
(random activity).

Location: Pine Valley Viewpoint 116 29' 43" W 32 49' 49" N  ELE = 1300 m

Bortle Scale Estimate: Class III Rural Sky

Beginning Temperature/Relative Humidity: 70 F (21 C) 50%
Ending              "               "             "        72 F (22 C) 55%

MAGNITUDES:

ANT:  -1 (1) 0 (1)  +1 (2) +2 (2) +3 (1) +4 (4) +5 (1)   AVE: +2.42

PER : -7 (1) -5 (2) -4 (2) -3 (1) -2 (4) -1 (9) 0  (16) 
         +1 (17) +2 (27) +3 (24) +4 (17) +5 (8) +6 (1)     AVE: +1.67

NPX:  0 (0) +1 (0) +2 (0) +3 (2) +4 (1) +5 (0) +6 (0)   AVE: +3.33

SPX:  0 (0) +1 (2) +2 (1) +3 (1) +4 (0) +5 (0) +6 (0)   AVE: +1.75

SPO:  -3 (1) 0 (1) +1 (1) +2 (6) +3 (3) +4 (10) +5 (9) 
          +6 (2)   AVE: +3.52

Bob Lunsford
San Diego, CA USA



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