[extropy-chat] Watching the comets, Part II

Amara Graps amara at amara.com
Tue Apr 27 14:58:07 UTC 2004

Hal Finney:
>One thing to keep in mind with comet magnitudes is that those reflect
>total light emission from the entire comet (or at least the coma).
>In other words, to compare it with a star of the same magnitude, you'd
>have to imagine squeezing down the extended visible area of the comet
>into a point, and then it would look as bright as the star.

Yes, that's true, I wasn't thinking about that aspect and it would
have been misleading to think it was as bright as point-like stars.

The northern comet (C/2002 T7 (LINEAR)) is visible, naked-eye, now,
nonetheless. It spans about 4 degrees from coma to tail(s). My comet
friends tell me it is at fourth magnitude. To find it, go to the
border of the constellations Andromeda and Pisces, find the star
delta And and follow it a few degrees and you'll see the comet. When I
learned this a couple nights ago, I was on travel in Nice, France (for
a follow-up scientific meeting for the Dawn asteroid mission I wrote
about last last Friday night), I ran my astronomy programs on my Mac
to see the sky view and set my alarm clock for 3am. I was more or less
prepared, I thought the horizon view from the promenade along the Nice
sea coast would be a perfect view. Alas, I was too tired, the last
weeks' travel and activities put me beyond exhaustion, and I slept
through my alarm. Missed my chance. I will try from the Rome mountains


Amara Graps, PhD             email: amara at amara.com
Computational Physics        vita:  ftp://ftp.amara.com/pub/resume.txt
Multiplex Answers            URL:   http://www.amara.com/
"The man who doesn't know what the universe is doesn't know where he
lives."      -- Marcus Aurelius

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