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Re: A five-year sequence of daily observations has yielded a surprise about our Sun

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nuny@bid.nes <Alien8752@gmail.com> wrote:
> On Monday, September 7, 2015 at 4:46:05 PM UTC-7, ji...@specsol.spam.sux.com wrote:
>> nuny@bid.nes <Alien8752@gmail.com> wrote:
>> > On Monday, September 7, 2015 at 9:45:45 AM UTC-7, Sam Wormley wrote:
>> >> A five-year sequence of daily observations has yielded a surprise about 
>> >> our Sun
>> >> > http://scitation.aip.org/content/aip/magazine/physicstoday/news/10.1063/PT.5.7199
>> >> 
>> >> > As hikers and other navigators know, Earth's magnetic axis is tilted
>> >> > with respect to its rotation axis. Such misalignment had not been
>> >> > expected in the Sun--but now it's been seen. NASA's Solar Dynamics
>> >> > Observatory (SDO) has been trained on the Sun for half of the current
>> >> > 11-year cycle of solar activity. Using SDO's Helioseismic and
>> >> > Magnetic Imager, Adur Pastor Yabar of the Institute of Astrophysics
>> >> > of the Canary Islands and his colleagues created daily maps of the
>> >> > line-of-sight strength and polarity of the Sun's magnetic field for
>> >> > each of the mission's first 1700 days.
>> > 
>> >   To drag the topic back to actual physics- does the surface rotation or
>> > the magnetic field axis maintain a constant direction on space?
>> > 
>> 
>> You mean other than the regular reversal with every sunspot cycle?
> 
>   Yes, other than that. AIUI what we call surface rotation is inferred by tracking sunspots, but the Sun's magnetic field is (currently thought to be) mostly generated in the shear zone at the bottom of the convection zone where the core's more-or-less coherent solid-body-like rotation gives way to messy vertical motion in the convective layer.
> 
>   I'd expect the core's spin axis to remain constant in space.
> 
>   It would seem to me therefore that sunspot motion doesn't really tell us anything about the rotation rate of any part of the Sun other than the shear zone. Sorry, "tachocline". I just looked it up.
> 
>   So, ignoring sunspots, I see no clear way to determine the rotation of the surface.
> 

The Sun is not featureless, uniform ball with occasional spots.


-- 
Jim Pennino

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A five-year sequence of daily observations has yielded a surprise about our Sun Sam Wormley <swormley1@gmail.com> - 2015-09-07 11:45 -0500
  Re: A five-year sequence of daily observations has yielded a surprise about our Sun jimp@specsol.spam.sux.com - 2015-09-07 16:55 +0000
    Re: A five-year sequence of daily observations has yielded a surprise about our Sun Sam Wormley <swormley1@gmail.com> - 2015-09-07 12:04 -0500
      Re: A five-year sequence of daily observations has yielded a surprise about our Sun jimp@specsol.spam.sux.com - 2015-09-07 17:31 +0000
      Re: A five-year sequence of daily observations has yielded a surprise about our Sun Poutnik <poutnik4nntp@gmail.com> - 2015-09-07 20:02 +0200
        Re: A five-year sequence of daily observations has yielded a surprise about our Sun gilber34 <invalid@invalid.com> - 2015-09-07 13:15 -0500
        Re: A five-year sequence of daily observations has yielded a surprise about our Sun Yousuf Khan <bbbl67@spammenot.yahoo.com> - 2015-09-07 14:43 -0400
  Re: A five-year sequence of daily observations has yielded a surprise about our Sun "nuny@bid.nes" <Alien8752@gmail.com> - 2015-09-07 16:12 -0700
    Re: A five-year sequence of daily observations has yielded a surprise about our Sun jimp@specsol.spam.sux.com - 2015-09-07 23:31 +0000
      Re: A five-year sequence of daily observations has yielded a surprise about our Sun "nuny@bid.nes" <Alien8752@gmail.com> - 2015-09-07 18:36 -0700
        Re: A five-year sequence of daily observations has yielded a surprise about our Sun jimp@specsol.spam.sux.com - 2015-09-08 03:40 +0000
    Re: A five-year sequence of daily observations has yielded a surprise about our Sun jaymoseley@hotmail.com - 2015-09-08 03:14 -0700
    Re: A five-year sequence of daily observations has yielded a surprise about our Sun Sam Wormley <swormley1@gmail.com> - 2015-09-08 08:44 -0500
  Re: A five-year sequence of daily observations has yielded a surprise about our Sun trudi.schwander@gmail.com - 2015-09-08 05:42 -0700
    Re: A five-year sequence of daily observations has yielded a surprise about our Sun Sam Wormley <swormley1@gmail.com> - 2015-09-08 08:33 -0500
      Re: A five-year sequence of daily observations has yielded a surprise about our Sun gilber34 <invalid@invalid.com> - 2015-09-08 10:11 -0500

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