# Sunspot 486 - Will it return?

**URL:** <https://boards.straightdope.com/t/sunspot-486-will-it-return/211626>\
**Category:** Factual Questions\
**Created:** [November 5, 2003, 11:20pm UTC](https://boards.straightdope.com/t/sunspot-486-will-it-return/211626 "2003-11-05T23:20:34Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![aerodave](https://avatars.discourse-cdn.com/v4/letter/a/f08c70/32.png) [@aerodave](https://boards.straightdope.com/u/aerodave)\
**Post date:** [November 5, 2003, 11:20pm UTC](https://boards.straightdope.com/t/sunspot-486-will-it-return/211626/1 "2003-11-05T23:20:34Z")

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The ‘486’ sunspot system has been hammeringus with all these exciting flasres and Coronal Mass Ejections lately, and it’s made for some good news. But now, it’s disappearing around the western limb of the sun.

So the question is, will we see this sunspot system again? The sun’s rotational period ought to bring that part of the surface back into view in about 13 days. Will the disturbance stay active that long? How long do sunspots normally survive, and do we ever see the same ones come around on successive rotations?

The reason I ask is because heavy cloud cover kept me from seeing the auroras that appeared last week. I was hoping for a second chance.

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**Author:** ![Squink](https://avatars.discourse-cdn.com/v4/letter/s/b5e925/32.png) [@Squink](https://boards.straightdope.com/u/Squink)\
**Post date:** [November 6, 2003, 12:34am UTC](https://boards.straightdope.com/t/sunspot-486-will-it-return/211626/2 "2003-11-06T00:34:29Z")

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From today’s Sky and Telescope AstroAlert:

> [@](#):
>
> Region 10486 has now rotated behind the western limb and out of view. It will now spend the next two weeks traversing the far side of the Sun. Whether it survives its passage on the far-side and returns to the eastern limb in two weeks in a form still capable of producing energetic events remains unknown. It is possible it could return in a form still capable of producing energetic events, but the odds are against it.

The X30 to X40 class flare and mass ejection occured when the spot group was just passing beyond the limb of the sun, so most of the junk is **not** headed our way. Still, it may be worth looking for aurora on the 6th when whatever is coming this way is expected to hit.

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**Author:** ![CurtC](https://avatars.discourse-cdn.com/v4/letter/c/ce73a5/32.png) [@CurtC](https://boards.straightdope.com/u/CurtC)\
**Post date:** [November 6, 2003, 4:03am UTC](https://boards.straightdope.com/t/sunspot-486-will-it-return/211626/3 "2003-11-06T04:03:03Z")

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When it comes out again, it will be even more powerful, and called “Sunspot Region Pentium.”

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**Author:** ![scr4](https://avatars.discourse-cdn.com/v4/letter/s/59ef9b/32.png) [@scr4](https://boards.straightdope.com/u/scr4)\
**Post date:** [November 6, 2003, 7:11am UTC](https://boards.straightdope.com/t/sunspot-486-will-it-return/211626/4 "2003-11-06T07:11:22Z")

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We’ll almost certainly see _something_ when that part of the sun comes into view again. Whether it’s a very weak remnant of an active region or a strong one, we don’t know.

We now have a limited capability to look at the [far side of the sun](http://soi.stanford.edu/data/farside/index.html) using a technique called helioseisimology. It’s the same principle as observing a powerful earthquake all over the world and calculating the earth’s density variations based on arrival time of the seismic waves. Except the sun is constantly vibrating, so we can get useful data any time.