(meteorobs) December 12, 2004 Meteor Observations from California

[Robert Lunsford]

I observed on this final night of the Geminid watch from a tranquil heli-pad
site. Despite the light dome in the west, the sky was very impressive with
stars visible right down to the horizon. I also had some deep limiting
magnitude estimates, with a couple of them exceeding +7.0 in Leo. Meteor
rates were down to normal with the Geminids only contributing nine meteors
during the 150 minute watch. The Geminids were still fairly bright with a
average magnitude of +1.89. The highlight of this session was an impressive
orange anthelion meteor that shot into the southern sky, producing sparks as
it disintegrated. To attest to the transparency of the sky, just before I
left I was able to spot the stars of western Scorpius, which were just in
conjunction with the sun the last week of November. Antares should soon
follow.

December  15, 2004

1100-1200 UT   1.00   6.94    1 ANT  2 COM  3 GEM  2 HYD  0 MON
                                               1 PUP   8  SPO  17 TOTAL

1200-1330 UT   1.50   6.69    0 ANT  2 COM  6 GEM  1 HYD  0 MON
                                               0 PUP   11 SPO  20 TOTAL

TOTALS:           2.50   6.79    1 ANT  4 COM  9 GEM  3 HYD
                                               0 MON  1 PUP   19 SPO
                                               37  TOTAL METEORS

The first column gives the period watched in Universal Time (UT)
which is PST + 8 hours. The second column gives the percent of that
particular hour actually spent observing the sky (1.00 = 100%, 0.99
= 99%). Time is lost for breaks and plotting. I was recording data on a
cassette recorder tonight so each hour was a full sixty minutes of
observing. No breaks other were taken as I was able to take the
recorder with me as I occasionally stood up and stretched. The third
column gives the average limiting magnitude estimated during each
period. The last several columns list the activity for expected active
radiants during each period. Quite often no activity is observed and
rates equal zero. Tonight I was facing south with my field of view
centered at 50 degrees altitude. ANT = Antihelion radiant (Xi Orionids),
COM = Coma Berenicids, GEM = Geminids, HYD = Sigma Hydrids,
MON = Monocerotids, PUP = Puppid/Velids and SPO = Sporadics
(random activity).

Location: Deerhorn Valley Helipad 116 40' 04" W 32 44' 52" N  ELE = 750 m

Bortle Scale Estimate: Class 3: Rural Site

Beginning Temperature/Relative Humidity: 45 F (7 C)  53%
Ending              "               "             "        45 F (7 C)  54%

MAGNITUDES OF INDIVIDUAL METEORS PER RADIANT:

ANT:   -2 (1) +1 (0) +2 (0) +3 (0) +4 (0) +5 (0)   AVG:  -2.00
COM  -1 (1) +1 (1) +2 (0) +3 (0) +4 (2) +5 (0)    AVG: +2.00
GEM:   0 (2) +1 (3) +2 (1) +3 (1) +4 (1)  +5 (1)   AVG: +1.89
HYD:  -1 (1) +1 (0) +2 (0) +3 (1) +4 (1) +5 (0)    AVG: +2.00
PUP:    0 (0) +1 (1) +2 (0) +3 (0) +4 (0) +5 (0)    AVG: +1.00
SPO:   0 (1) +1 (4) +2 (2) +3 (6)  +4 (4) +5 (2)    AVG: +2.74