[Prev][Next][Index][Thread]

(meteorobs) Dec. 22 Meteor Observations From California



I had the pleasure of observing with fellow meteorobs member Michael
Doyle. We watched from an elevated clearing south of Descanso. This site
has a particularly good northern horizon. There was some thin cirrus
present as we started counting near 10pm (0600 UT). Rates were quite low
the first two hours and the expected maximum came and went without much
activity. Ursid activity picked up noticeably during the third hour but
unfortunately so did the cirrus cloud cover. Very few Ursids were seen
near the radiant. Michael was seeing some over in Leo while a hot spot
for me was through Perseus heading toward Jupiter and Saturn. The few
that were seen close to the radiant were notable. Although short, they
were long lasting and usually bright. No Ursids exhibited any color
other than white. One of the 2nd magnitude sporadics was a distinct
yellow. This meteor was also one of the slowest of the session. One
sporadic also lined up with the antihelion radiant now located in
Gemini. The last hour was a disaster. I decided to switch from plotting
to recording on my cassette recorder as activity was increasing. Shortly
after the top of the hour the cirrus increased and effectively put an
end to the session. This was a shame as Ursid activity was increasing
and we were looking forward to more impressive meteors. 

It seemed to me that Michael was seeing more Ursid activity early on
than me. By the 3rd hour I probably caught him and may have passed him
on Ursid activity. He had a long day (flying out here from VA) and
staying alert may have been a problem after his 2nd hour. Being up 24
hours straight did not help me any. It was quite a chore staying alert
during that last hour with the clouds reducing the activity.

December 22, 2000

0600-0700 UT  0.95  1.00   6.48  0 COM   2 URS   4 SPO   6 TOTAL  
0700-0800 UT  0.98  1.00   6.38  0 C0M   1 URS   3 SPO   4 TOTAL
0800-0900 UT  0.92  1.33   6.22  0 COM  10 URS   5 SPO  15 TOTAL
0900-1000 UT  1.00  4.00   5.59  0 COM   2 URS   2 SPO   4 TOTAL
 
TOTALS:       3.85  1.86   6.16  0 COM  15 URS  14 SPO  29 TOTAL


The first column gives the period watched stated in Universal Time (UT)
which is PDT + 8 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 correction
for clouds. 1.00 is perfectly clear while 4.00 is 75% obscured. The
fourth column gives the average limiting magnitude estimated during each
period with a minimum of 4 estimates using at least 2 and preferably 3
different sky areas close to my center of view. The last several columns
list the activity seen during each period. I was facing nouth at an
altitude of 60 degrees during the entire session. No breaks were taken.
COM = Coma Berenicids (Northern Apex), URS = Ursids, and SPO = Sporadics
(random activity). 

Beginning Temperature/Relative Humidity:   42 F (6 C)  35%
Ending         "         "         "       43 F (6 C)  34%

MAGNITUDES:  

COM:         0 (0) +1 (0) +2 (0) +3  (0) +4 (0) +5 (0) AVERAGE: 
URS:         0 (1) +1 (3) +2 (5) +3  (3) +4 (3) +5 (0) AVERAGE: +2.27
SPO:         0 (0) +1 (0) +2 (5) +3  (6) +4 (3) +5 (0) AVERAGE: +2.86

Bob Lunsford
San Diego, CA USA
To UNSUBSCRIBE from the 'meteorobs' email list, use the Web form at:
http://www.tiacdot net/users/lewkaren/meteorobs/subscribe.html