Space/Science » in reply to Re: No shadow at all . . .

Sure looks like a shadow to me...

Nathan Koren — 3/26/2002 6:57:21 PM (archived)

I understand the effect that you're talking about -- the center of the cone appears to be dimmer because you are seeing through fewer particles -- for exactly the same reason that the sky is darker at the zenith than at the horizon. However, assuming that the particle-cloud that you're looking through has a roughly cylindrical or spherical shape, the brightness falloff should roughly fit to a sine curve. That's not what I'm seeing here -- there's a clearly delineated "divit" that originates at the nucleus and continues throughout the tail at a very narrow angle. If this isn't the shadow of the nucleus, then it must be an actual physical bifurcation of the tail (which is also a possibility).

Cheers,

Nathan.

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The whole thread (23 posts)

• The nucleus of comet Ikeya-Zhang . . . - D. Spires - 3/25/2002 11:24:46 AM
  • Re: I am bummed. I want to see, I want to see. - Dan Apted - 3/26/2002 4:31:16 PM
    • Re: Took over 30 minute to load on mine . . . - D. Spires - 3/26/2002 4:54:43 PM
      • Re: Maybe this will help - SteveS - 3/26/2002 6:11:03 PM
      • Re: I am an internet provider with 9 t1's but I am at home now on a 1.2mb DSL and it is still very slow. Gotta go to work now, I hope it will be finished by the time I get home. (n/t) - Dan Apted - 3/26/2002 6:02:33 PM
      • I couldn't wait. I just clicked on the blank space and a smaller version downloaded real quick. :) n/t (n/t) - Marcia - 3/26/2002 5:11:55 PM
  • Re: The nucleus of comet Ikeya-Zhang . . . - Nathan Koren - 3/25/2002 1:35:22 PM
    • That shadow.. - Marcia - 3/26/2002 2:24:58 PM
      • There's definitely a shadow in that one. n/t (n/t) - Marcia - 3/26/2002 2:27:00 PM
        • Re: No shadow at all . . . - D. Spires - 3/26/2002 4:05:50 PM
          • Sure looks like a shadow to me... - Nathan Koren - 3/26/2002 6:57:21 PM
            • Re: The peak of the sine . . . - . Spires - 3/26/2002 7:53:30 PM
              • Re: I left out a word . . . - D. Spires - 3/26/2002 7:55:42 PM
              • Light and Shadow - Nathan Koren - 3/26/2002 10:20:17 AM
                • Gah, typos! - Nathan Koren - 3/26/2002 10:24:01 AM
                  • Re: My comparison was nothing more than a weak parallel . . . - D. Spires - 3/26/2002 10:55:48 AM
                    • This is getting silly... :-) - Nathan Koren - 3/26/2002 12:48:18 PM
                      • Re: Just realized something here . . . - D. Spires - 3/27/2002 2:00:23 PM
                        • Re: Just realized something here . . . - Nathan Koren - 3/27/2002 6:48:05 PM
                      • Re: I already agreed -- to a degree . . . - D. Spires - 3/26/2002 1:24:17 PM
                        • Okay, so we agree then! :-) - Nathan Koren - 3/27/2002 6:50:50 PM
          • Re: To clarify what is so obviously wrong with my post . . . - D. Spires - 3/26/2002 4:12:01 PM
            • Yes, Dan and great 'V' explanation! n/t (n/t) - Marcia - 3/26/2002 5:00:19 PM