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response to meteor messages
After getting 42 messages in three days I need to get a general response out
to all of them. This will be one big hodgepodge of thoughts.
I prefer to get a couple of hours sleep before going observing. If I fade
while out there, I take a nap after an official hour has been completed.
Usually I will wake up a half hour or so later feeling much better.
On a cold night the tape recorder has to be kept inside the sleeping bag or
under the covers. The same goes for my timepiece, usually an alarm clock.
The clock slows down or stops below 60 degrees F.
Meteors from radiants below the horizon are interesting. Two I definitely
remember were a 1972 Quadrantid in deep evening twilight and a Day Beta
Taurid in 1976.
Color perceptions interest me a lot. Eyes seem to determine color
overwhelmingly. For the 1980 Perseids 3 of us in the Florida Keys (Norman
McLeod, Felix Martinez, and Lew Gramer) did detailed color charts. Each of
us had yellow as dominant with 2 other colors as semi-dominant. My two were
blue and orange, Felix's were blue and green, and Lew's were orange and
green. I was struck by the 3 of us covering all combinations of 2-color
selections from the set of 3 colors.
A second type of color perception is by magnitude for getting any coloring
at all. I see all meteors of +1m as colored, about 60% of +2m's, 10% of
+3m's, and occasionally a fainter one which is always orange. A bright and
pure white meteor is rare for me. Distance from central vision is
irrelevant in my case. No matter how poorly seen a meteor is, I perceive a
color if it is above my brightness threshhold. A fireball lighting the
ground also reveals its color, from -4m on up.
For individuals whose DCV does determine whether color is seen, a third
derivation is needed. Bob Lunsford, for example, reports that he loses
color beyond 40 or so degrees out from central vision.
I would like to see detailed color studies from other observers. Jeff
Wood's group for years reports a lump color perception of roughly 30% for
meteors of +2m or brighter. That is not very much color! I have never
received any detailed breakdown from them. As for what scientific use color
is, I couldn't say. But it sure is interesting to play with.
A time cube would be very useful on the stronger major shower maxes. Why
bother with it on nights with low rates?
Epsilon Lyrae I can split easily. For stationary objects my eyes are
superb. I usually see 0.5m to 1.0m better than most other people I'm with.
I have worn glasses since age 16. Today I'm nearsighted as bad as ever,
about 20/80, but I correct to 20/10 or better. No need for bifocals yet
(turning 50 on June 3.) My father was 54 when he needed bifocals so I
should be good for 4 more years. For meteors my perception is flat normal.
Most showers I see the observed rates published over the years, but the
Perseids I am usually well short on. It's not my latitude: longer summer
nights here offset the lower radiant altitude by allowing it extra time to
rise almost as high here as in the northern U.S.
Another math-filled meteor book is "The Physics of Meteor Flight in the
Atmosphere." I don't recall the author. Was never interested in reading
this myself.
I know when thin cirrus is present at night: the LM is poorer. This isn't
usually the cause of poorer nights in Florida, rather it's hazy or smoky or
humidity-laden air. One night in the Keys back in 1973 we had a night where
LM6.0 persisted all night due to thin uniform cirrus. Most nights there
were 7.2 to 7.5. I don't mention it as a percentage of cloud cover because
of the uniform reduction over the entire sky. Broken cirrus is the worst to
deal with. I try to turn away from it until I get boxed in, then I need to
mention it in my notes. If a meteor is seen through a cloud or definite
localized haze, I note that. So my magnitude tables are kept pure, I omit
hazily-seen meteors.
That's all for now. Norman W. McLeod III