Sept(i think) Sky and Telescope had an interesting project for measuring degrees in the sky. The metric is develpoed u sing a yard stick (36inches) nailed to the end of a length of board then pulled back into an arc of prescribed radius, each inch mark equals an increment of arc. I'm writing this from memory if you wish I'll get the recipe.
Joe Talbert
-----Original Message-----
From: Kim S. Youmans [SMTP:ksyo@pinelanddot net]
Sent: Saturday, September 04, 1999 06:37 PM
To: Meteorobs
Subject: (meteorobs) Plotting: Three Stooges Method
Hello All,
As part of my continuing education in meteor observation, I
have slowly been working my way into plotting. I must admit, never have
I found anything that seemed so deceptively simple to be so
confoundingly frustrating. A typical attempt at plotting a single
meteor may go something like this:
5:40 UT, a meteor appears that *may* be coming from a known
radiant. I decide to plot it. I throw my ruler up into the air to
"place" the path.
5:40:30, I feel I have the path, now I need to see the time. I
grope for my recorder, finally find the pause button, while still
holding the ruler to the sky. I look down at the watch glued to the
recorder. I look back up, and I no longer have the ruler placed exactly
where it should be. I place it back where I think it should be.
5:41:30 I stare and stare and stare at that region of the sky and
finally realize the meteor was over the peak of Ophiuchus.
I cautiously put the ruler down and reach for my red light and charts.
I turn on the red light, and in order to free up my hands for plotting,
hold the light in my mouth. I get stung on the tongue by an ant. I
spit the ant and several grains of sand out, then return to the chart.
5:42:30 An outburst of 15 simultaneous meteors occur while I am
staring down at my charts. By now I can't remember
which direction the meteor was traveling, or what the beginning and end
point was, if I ever had them well to begin with. I "plot" the meteor
just as the cat jumps on my lap and all my tools get scattered.
5:43:30 A magnitude -7 fireball appears while I am looking down to
gather up my pencil, chart, ruler and recorder. My chewing gum, I
notice, is quite gritty with sand now.
And that was an EASY one! Actually, most of the meteors appear
within my field of view, and go quickly on the chart I have out and I
don't really lose that much time. But the most frustrating thing of
all, I think is getting home and not being able to accurately predict
the radiant drift for various minor shower radiants due to the
inadequacies of my charts. I still don't know what one grid on the
Atlas Bruno chart represents, in degrees, and my Petersons charts have
the RA and dec, but I can't translate that well into actual degrees.
So a few questions: If I hold my 12" ruler to the sky at arms
length, how many degrees of sky am I covering? It is approximately the
distance from Deneb to Altair. I know the rule of thumb about fist size
being 10 degrees and open hand being about twenty, but there can be a
wide variation there among individuals.
Also, do I need to join a guild or a lodge to get the secret
information contained within those plotting charts? If I could
accurately measure distance on those charts, I wouldn't have to
aggravate Mark, Wayne, and others for current radiant positions. Or is
there some easier way that I'm missing altogether? (Wayne, I didn't get
the current Piscid position:>)
But until I started plotting, I never realized I had so many thumbs.
Thanks in Advance, Kim S. Youmans
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