(meteorobs) December 21, 2004 Meteor Observations From California

[Robert Lunsford]

I observed from the Pine Valley Viewpoint this morning as my other sites
closer to home were clouded out. The sky this morning was truly spectacular.
The sky was filled with seemingly countless numbers of faint stars. The star
counts confirmed these conditions as counts down to +7.3 were achieved.  The
only hint of light pollution was from lights in the Los Angeles area
bouncing off high clouds low in the northwest. One would think that under
such conditions there would be many faint meteors visible. Well, if there
was, these old eyes were not seeing them.

The session started out a bit slow with only ten meteors. The only two
Anthelion meteors seen during the night occurred during the first half hour
of the watch. They were both bright and appeared close to Polaris. The only
Ursid was seen thirty minutes into the watch. This was a short, faint (+4)
meteor some twenty degrees east of the center of my field of view. I really
had to think about whether it was real or not before plotting it. There was
another possible Ursid, seen further out that I wrote off as a eye flash or
simply "wishful thinking". I could not convince myself that it was real,
especially being so faint (+5) and so far from the center of my field of
view.

With my center of view just west of the bowl of the Big Dipper, I was seeing
many meteors passing through the tail of Draco toward the bowl of the Little
Dipper. I was thinking most of these meteors were members of the Coma
Berenicids but plots proved this to be incorrect. Only three positive
(correct path and angular velocity) members of the COM's were seen. Seven
other meteors seem to come from a radiant further west near 10:30 (157) +25.
These could be related to Norman's "December Leonids" as the radiant would
have been near the "sickle" of Leo last week. By the way I was looking for
any December Leonids during the Geminids and any possible members were few
and far between. Most of those candidates were just too swift and fit the
parameters of the Coma Berenicids much better. Kim Youmans also reported
high COM activity on December 22 last year so perhaps these meteors are
related to what he witnessed. It will be interesting to see if there is a
repeat performance tomorrow.

By the way, I would have stayed out a bit longer but clouds from the north
quickly blotted out the sky shortly after 445am local time. These clouds
have since left the area so prospects for tonight are favorable.

December 21 , 2004

1030-1135 UT   1.00   6.96    2 ANT  0 COM  1 URS   7  SPO
                                                10 TOTAL

1135-1242 UT   1.00   7.03    0 ANT  3 COM  0 URS  14 SPO
                                                17 TOTAL

TOTALS:           2.00   6.99    2 ANT  3 COM  1 URS  21 SPO
                                                27  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.  No breaks were taken.
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 north with my field of view
centered at 50 degrees altitude. ANT = Antihelion radiant,COM =
Coma Berenicids, URS = Ursids and SPO = Sporadics (random
activity).

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

Bortle Scale Estimate: Class II (Typical Truly Dark Site)

Beginning Temperature/Relative Humidity: 41 F (5 C)  55%
Ending              "               "             "        37 F (3 C)  54%

MAGNITUDES OF INDIVIDUAL METEORS PER RADIANT:

ANT:    0 (0) +1 (1) +2 (1) +3 (0) +4 (0) +5 (0)   AVG:  +1.50

COM   0 (1) +1 (0) +2 (2) +3 (1) +4 (0) +5 (0)    AVG: +2.67

URS:    0 (0) +1 (0) +2 (0) +3 (0) +4 (1) +5 (0)    AVG: +4.00

SPO:   0 (1) +1 (3) +2 (2) +3 (8)  +4 (6) +5 (1)    AVG: +2.86


Bob Lunsford
San Diego, CA