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(meteorobs) Yes, the Delta Cancrids exist...


>To: Local meteor folks...
>Cc: Amateur Telescope Makers of Boston


I can now vouch for the DCAs, since I've plotted two myself. :)

I completed a very enjoyable (albeit lonely) plotting session early Sunday
morning, after spending an often frustrating but finally wonderful evening
dodging clouds and exploring the Deep Sky with the 20" and Steve C., Jim and
Dave of the ATMs of Boston, as well as several interested newcomers.

After the Deep Sky crew left for the night, I set up under a half-cloudy sky,
with some of the more unusual cloud conditions I've so far recorded during a
meteor session: the SE half the sky was rapidly covered by a cirrocumulus deck
below the already present Cirrus layer there. However, the rigid cloudline of
Cc remained stationary just over the zenith for nearly an hour, never once
covering any major part of the NW sky! This strangely accommodating cloudline
allowed me to plot for 1.28 hours Teff - my first successful watch in 1999!

Best meteor of the night was a casual fireball at 00:45:05 UT, a -4
blue-white Sporadic with 1-second train, noted 5o E of Diphda in Cetus.

Low point of the watch was having all the lights of the compound turned on by
inattentive MIT Security folks, turning them all back off myself, then hearing
the wind set off the alarms in the Submillimeter Telescope assembly building
for five minutes immediately afterward. All nothing but a minor annoyance.

HIGH point for the night was seeing Mars 5o NNE of Spica: The color contrast
of this "naked-eye pair" were such that Spica appeared distinctly blue. But
though the colors were reminiscent of Albireo in Cyg, these two mag 1 objects
were close enough in brightness, that they created the impression of a lovely,
strange pair of eyes - one gold, one blue - blinking languidly in the sky.


Below is my meteor data summary for the night. For those unfamiliar with such
summaries, "DCA" and "COM" are abbreviations for the two (IMO) showers I
watched for during that session (Delta CAncrids and COMa Berenicids); "F" is a
correction factor for cloudcover (which averaged 5% during the watch), LM is
my average naked-eye Limiting Magnitude, CFV the coordinates of the Center of
my Field of View, and all times are recorded as Universal Time.

GRALE, 16/17 Jan 1999, MIT Haystack Observatory, Westford, MA, USA
Summary of All Meteor Data for the Session
  Start End     CFV     Teff    LM      F       DCA     COM     Spor    TOTAL
1 7:35  9:15    08h+60  1.28    6.36    1.066   2       2       12      16
Average Magnitudes                              3.25    1.50    2.92    2.78

MAGNITUDE DISTRIBUTIONS
        -1      0       1       2       3       4       5       6       TOTAL
DCA     0       0       0       1       0       0.5     0.5     0       2
COM     0       0       1       1       0       0       0       0       2
Spor    0       0.5     1       3       3       3.5     1       0       12
TOTAL   0       0.5     2       5       3       4       1.5     0       16

Also plotted during the night: three possible Alpha Hydrids (non-IMO shower),
two possible Zeta Aurigids (ditto), and one possible January Draconid (ditto).
All plot charts will be forward to Mark Davis of N.A.M.N. for archiving.

Clear skies!
Lew Gramer
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