(meteorobs) Visual Observations from Southern CA 8/13/10

[Robert Lunsford]

I was out for three nights to view the Perseids. I'm posting data from the night of maximum first as I don't know when I will have
time to post the other two.

I had planned to view from the Alpine Viewpoint, but it was crowded so I decided to head up to my Pine Valley viewpoint on
Mt. Laguna. Although also crowded, this site had plenty of parking. The sky was brilliantly clear but not as dark as I had hoped. 
The
normal marine layer of clouds, which usually shrouds San Diego with clouds at night this time of year, was absent.  I decided to
face northward to avoid the sky glow to the west and the mountain peaks to the east. I still managed to get a limiting magnitude of
+6.82, which is not too shabby considering my old, tired eyes.

The video camera was started at 0022 PDT and I started counting at 0031 PDT. Breaks were often necessary to change the batteries and
tapes in the video recorder. The first hour provided 32 meteors, 25 which were Perseids. I was hoping that a mother nature would 
provide all these folks a bright meteor before they began to head home. My wishes were answered at 0106 PDT when a -bright Perseid 
shot upward from the radiant and through the zenith. It flared to magnitude -7 and left a twisting train that lasted nearly two 
minutes. There were lots of oohs and awes over that one! My friend, Dennis Mammana, observing from the desert near Borrego Springs, 
some 30 miles to the NE, managed to photograph the train. See
http://spaceweather.com/submissions/large_image_popup.php?image_name=Dennis-Mammana-Perseid-2010-Trail-Mammana_1281723142_fl.jpg

An Eridanid earthgrazer of 2nd magnitude was seen low in the north heading northwest. Despite the average magnitude, this meteor was 
distinctly orange and impressive.

Perseid rates nearly doubled during the second hour with 43 being seen. The brightest was a -3 that occurred at 0156 PDT. Another 
identical Eridanid was seen during this period. I use to think these meteors were from Cetus until the IMO video section pinpointed 
their radiant, just east of Cetus in western Eridanus. 13 sporadics were also seen this hour, undoubted some of them were also 
Anthelion or late Delta Aquariid meteors.

Some some reason rates fell during the third hour. I was forced to take a 5 minute break to change the battery and tape in the video 
recorder, but rates were still below those expected for a 55 minute period. The brightest Perseid seen during this period was a 
magnitude -2. Only 7 sporadics and no other shower meteors were noticed.

The last full hour produced the best rates of the night. A total of 64 meteors were seen, 52 of them being Perseids. Four negative 
magnitude Perseids were seen during this period with a magnitude -3 being the brightest. Another 2nd magnitude Eridanid was seen, 
this one not quite so long as the radiant had risen higher in the southeast. 11 sporadics were also seen.

The last period of the night was a 37 minute session that lasted up until the sky was getting bright in the northeast. This session 
provided 45 meteors with 38 of them being Perseids. My one and only Beta Perseid was seen during this time as it missed the main 
Perseid radiant by a good ten degrees. A -5 Perseid was seen low in the NE against the brighting sky just two minutes before I quit 
for the night.

No distinct enhancement occurred near 0500 PDT from the 441 trail, but I got the impression that rates were still climbing. Many 
observers noticed clumping in the display of Perseids, which is perfectly normal. This year I found the clumping effect to be 
minimal rarely a gap of more than a couple of minutes between meteors. It was a nice, bright show that will certainly wet my 
appetite to view the Geminids next December.

-------------------------------------------------------
Observer: Robert Lunsford (LUNRO)
Date: 10-Aug 13 Mean Solar Long: 140.396
Beginning Time (UT) 0731 Ending Time (UT) 1208
Total TeFF: 5.00

LOCATION: Pine Valley Viewpoint, CA, USA
LONG: 116 29' 43" W LAT: 33 49' 49" N
Elevation: 630 m Bortle Scale: Class 3: Rural Sky
Beginning Temperature/Relative Humidity: 59-38%
Ending Temperature/Relative Humidity: 50-51%
METHOD: Visual Recording on Tape/Video Recording
--------------------------
Showers Observed
BPE  03:20 (050) +38     00-00-00-00-01         1 Total
ERI   03:04 (046)  -09     01-01-00-01-00         3 Total
PER  03:12 (048) +58     25-43-38-52-38    196 Total
SPO                                   06-13-07-11-07      44 Total
Hourly Counts                 32-57-45-64-45    159 Total
---------------------------
Period 1   0731-0831 UT
F = 1.00 (0% Clouds)   Mean LM 6.79
FOV 330 +70   TOTAL TeFF: 0.92
Mean Solar Long: 140.336

Meteor Data:
BPE 0, ERI 1, PER 25, SPO 6,  TOTAL 32

Magnitude Distribution
ERI +2 (1)  Mean +2.00
PER -7 (1) -1 (1) 0 (1) +1 (5) +2 (5) +3 (8) +4 (2) +5 (2)  Mean +1.96
SPO +2 (1) +3 (3) +4 (2)  Mean + 3.17
----------------------------

Period 2   0831-0931 UT
F = 1.00 (0% Clouds)   Mean LM 6.72
FOV 345 +70   TOTAL TeFF: 1.00
Mean Solar Long: 140.376

Meteor Data:
BPE 0, ERI 1, PER 43, SPO 13,  TOTAL 57

Magnitude Distribution
ERI +2 (1)  Mean +2.00
PER -3 (1) -1 (2) 0 (3) +1 (3) +2 (14) +3 (7) +4 (9) +5 (4)  Mean +2.40
SPO +2 (2) +3 (6) +4 (3) +5 (2)  Mean + 3.38
----------------------------

Period 3   0931-1031 UT
F = 1.00 (0% Clouds)   Mean LM 6.67
FOV 000 +70   TOTAL TeFF: 0.92
Mean Solar Long: 140.416

Meteor Data:
BPE 0, ERI 0, PER 38, SPO 7,  TOTAL 45

Magnitude Distribution
PER -2 (1) -1 (2) 0 (3) +1 (3) +2 (7) +3 (15) +4 (6) +5 (1)  Mean +2.29
SPO 0 (1) +1(2) +2 (0) +3 (1) +4 (3) +5 (0)  Mean + 2.43
----------------------------

Period 4   1031-1131 UT
F = 1.00 (0% Clouds)   Mean LM 6.59
FOV 015 +70   TOTAL TeFF: 0.95
Mean Solar Long: 140.456

Meteor Data:
BPE 0, ERI 1, PER 52, SPO 11,  TOTAL 64

Magnitude Distribution
ERI +2 (1)  Mean +2.00
PER -3 (1) -2 (2) -1 (1) 0 (4) +1 (13) +2 (8) +3 (12) +4 (9) +5 (2)  Mean +1.98
SPO 0 (0) +1(0) +2 (1) +3 (4) +4 (4) +5 (1)  Mean + 3.18
----------------------------

Period 5   1131-1208 UT
F = 1.00 (0% Clouds)   Mean LM 6.34
FOV 025 +70   TOTAL TeFF: 0.62
Mean Solar Long: 140.476

Meteor Data:
BPE 1, ERI 0, PER 38, SPO 7,  TOTAL 46

Magnitude Distribution
BPE +2 (1)  Mean +2.00
PER -5 (1) -2 (1) -1 (1) 0 (2) +1 (9) +2 (12) +3 (9) +4 (2) +5 (1)  Mean +1.98
SPO +3 (3) +4 (3) +5 (1)  Mean + 3.71
----------------------------

Total Magnitude Distribution
BPE +2 (1)  Mean +2.00
ERI +2 (3)  Mean +2.00
PER -7 (1) -5 (1) -3 (1) -2 (2) -1 (1) 0 (4) +1 (13) +2 (8) +3 (12) +4 (9) +5 (2)  Mean +1.98
SPO 0 (0) +1(0) +2 (1) +3 (4) +4 (4) +5 (1)  Mean + 3.18