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(meteorobs) July 13/14 Observations
The thunderstorms in our area finally cleared enough to allow me a try
at some rural meteor observing. I watched for 5 hours from a site off
Japatul Road, south of Descanso. Upon arriving the entire eastern sky
was obscured by high clouds from dissipating thunderstorms in the
desert. I was forced to face the northwest at the beginning of the
watch. As time progressed during the first hour the cloud cover lessened
and I was able to shift my sights more easterly, away from the city
lights of San Diego. It was not your typical dry mountain night, rather
it was wet, humid, and hazy. I only recorded 2 sporadics during that
first hour, a bit low since I was still able to obtain an average
limiting magnitude of 6.6. Only 4 meteors were seen during the second
hour including a faint South Delta Aquarid. Six meteors were seen during
the third hour including a faint Alpha Cygnid and a bright July Pegasid
with a one second train. During this hour more high clouds floated in
from the east causing me to change my center of view constantly. Luckily
the clouds obscured only a small portion of the sky allowing me to
continue observing. Counts dropped back to 4 during the fourth hour
including another Alpha Cygnid and a North Delta Aquarid. The clouds
cleared off again during the fifth and final hour and 9 meteors were
recorded. To my surprise the second to last and last meteors of the
session lined up with the July Phoenicid radiant which was lying on the
south-southeast horizon at the time. Both of these possible Phoenicids
were long and fast, typical of meteors whose radiant lies on the
horizon.
The total of 25 meteors seen for the session was quite a bit less than
expected but I am thankful that the clouds did depart allowing me to
observe for the first time in 3 weeks. After coping with the bright moon
and lousy weather the past 3 weeks I will not complain! No Alpha Caps,
Perseids, or Sagittarids were seen during this session.
July 13/14 1999
0630-0730 UT 0.98 6.60 0 ACG 0 JPE 0 NDA 0 PHE 0 SDA 2 SPO 2 TOT.
0730-0830 UT 0.97 6.50 0 ACG 0 JPE 0 NDA 0 PHE 1 SDA 3 SPO 4 TOT.
0830-0930 UT 0.95 6.36 1 ACG 1 JPE 0 NDA 0 PHE 0 SDA 4 SPO 6 TOT.
0930-1030 UT 0.97 6.16 1 ACG 0 JPE 1 NDA 0 PHE 0 SDA 3 SPO 4 TOT.
1030-1130 UT 0.93 6.08 0 ACG 0 JPE 0 NDA 2 PHE 0 SDA 7 SPO 9 TOT.
TOTALS: 4.80 6.34 2 ACG 1 JPE 1 NDA 2 PHE 1 SDA 19 SPO 25 TOT.
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. Time was lost for
plotting and data entry tonight. The third column gives the average
limiting magnitude estimated during each period with a minimum of 4
estimates using at least 2 different sky areas close to my center of
view. The last several columns list the activity seen during each
period.
During the first hour I was facing northwest to northeast at an altitude
of 70 degrees. During the last 4 hours I was mainly facing due east at
an altitude of 70 degrees but I often had to shift either north or south
to avoid clouds. No breaks were taken during this session. ACG = Alpha
Cygnids, JPE = July Pegasids, NDA = North Delta Aquarids, PHE = July
Phoenicids, SDA = South Delta Aquarids, and SPO = Sporadic (random
activity).
Beginning Temperature/Relative Humidity: 64 F (18 C) 72%
Ending " " " 57 F (14 C) 84%
MAGNITUDES:
ACG: +1 (1) +4 (1) AVERAGE: +2.50
JPE: 0 (1) AVERAGE: 0.00
NDA: +3 (1) AVERAGE: +3.00
PHE: +1 (1) +2 (1) AVERAGE: +1.50
SDA: +4 (1) AVERAGE: +4.00
SPO: -1 (2) 0 (1) +2 (6) +3 (5) +4 (3) +5 (1) AVERAGE: +2.21
Bob Lunsford
San Diego, CA USA
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