The Sun roils over Mexico

By Phil Plait | August 23, 2011 6:00 am

Yesterday, "amateur" astronomer César Cantú took an amazing mosaic image of the Sun, showing our star boiling and writhing under its own dynamic forces:

[Click to unGdwarfenate.]

That hardly looks like the Sun, does it? That’s because he used a filter that blocks all the light we see except for a very narrow slice of color in the red part of the spectrum. That filter lets through only light from warm hydrogen, at just the right temperature to allow the electrons in the hydrogen atoms to drop from the third energy level to the second. You can picture the electron in an atom like it’s on a staircase, and only allowed (by quantum mechanics) to sit on a step, or move from one to the other. It takes energy to move it up a step, and gives off energy when it moves down. When it jumps down from the third to the second, it emits a photon — a particle of light — at a wavelength of 656.3 nanometers, and astronomers call this light (H alpha).

The gas on the Sun’s surface emitting Hα is under furious stirring due to magnetic fields and other forces, and you can see that in the twisted, roiling appearance in this photo. I particularly like the dark arc just left of center: that’s a filament, an eruption of gas off the surface. It’s about 150,000 kilometers (90,000 miles) long! It’s a bit cooler than the surface material, so it’s darker, and we see it in silhouette. When those happen on the limb of the Sun they’re called prominences, and you can see several of those in this picture too.

Amazingly, this picture (which is really a mosaic of six separate shots) was taken using a telescope with only a 90 mm (3.5 inch) lens. The Coronado 90 mm telescope is a favorite of sidewalk astronomers, since it shows the Sun in amazing detail, but is totally safe to look through since it blocks almost all the Sun’s light. It’s common to see them at planetaria and museums, set up where passers-by can get a quick glimpse of the Sun. For most, it’s the first time they ever see the might and power of a star only 150 million kilometers away.

And if you want a sense of scale here, in the picture above the Sun is about 450 pixels across. On the same scale, our entire planet Earth would be only about 4 pixels across.

Just in case you were feeling big and important today.

Credit: Image used by permission of César Cantú.

Related posts:

A HUGE looping prominence on the Sun
The Sun blasts out a flare and a huge filament
The boiling, erupting Sun
Heart and skull nebula (another stunning shot by César)

CATEGORIZED UNDER: Astronomy, Pretty pictures

Comments (21)

  1. Stunning picture!

  2. It is indeed appropriate to use quotes around the word amateur for these guys! Well done!

  3. Ian

    So about this big then:-

    And to think how small we are on the surface of that tiny dot.

  4. kansel

    On the full size image there are two specks of light just off the sun. About 30 degrees up on the left side, about 70 pixels away from the limb, and about 45 degrees up on the right side about 100 pixels away. They are just a few pixels each. Are these artifacts or stars? If stars, can we know which stars they are?

  5. kevbo

    I see a fuzzy duck just to the right of the filament.


  6. oh thanks Kebvo,

    Now I cant see that picture of the sun without the fuzzy duck!

  7. BrianW

    Hah! You said unGdwarfenate. 😉 Amazing what you can see when you’re not starved for photons.

  8. Mejilan

    4 pixels? 4 pixels of awesome, you mean!

  9. Jason

    Fuzzy duck sounds like a drink.

  10. VJBinCT

    I see it as a coyote, appropriate for an observation from Mexico.

  11. feh

    Yes, that’s a duck and it seems quite fuzzy indeed. I wonder what’s it doing up there. It’s got to be enormous.

  12. ophu

    It may be more appropriate to call him a “stellar” photographer. :)

  13. Padawanninja

    Don’t need that pic to make me feel small. The earth here in VA just shook from a 5.8 hiccup a couple of km down.

    But the pic does help. 😛

  14. Larry

    “unGdwarfenate” is the best magnifier. Ever.

  15. Mephane

    If you think the size comparizon between Earth and Sun is stunning, look up one of those size comparisons of different stars!


  16. Messier Tidy Upper

    @ ^ Mephane : Or watch this :

    or this one :

    on youtube or even this musical one :

    (some mildly NSFW lang in that last one.) by Monty Python 😉 :-)

  17. Messier Tidy Upper

    That hardly looks like the Sun, does it?

    [Shrugs] Um ..looks perfectly like our daytime star to me.

    Perhaps I’m used to seeing such images. Nice one though. :-)

    Incidentally, our Sun looks vividly red through a Hydrogen alpha filter or at least in my experience it does. This is much more yellow than H-alpha would indicate to my mind.

    @10. Jason :
    “Fuzzy duck sounds like a drink..”

    An Aussie traditional one where you sit in a circle and the first person says “Fuzzy duck” the next “ducky fuzz” the third “Fuzzy duck” again and continue until someone says the wrong thing – at which point everyone drinks and the order changes direction and goes the other way. I think (#9) Larian LeQuella knows that one too somehow. 😉

    @12. feh :

    Yes, that’s a duck and it seems quite fuzzy indeed. I wonder what’s it doing up there. It’s got to be enormous.

    Its .. its heading our way! Everyone DUCK!!! 😮 😉

    (You know there’s a B-grade movie tale in that idea.)

  18. feh

    > Its .. its heading our way! Everyone DUCK!!!

    I, for one, welcome our new anatidae overlords. And their Jupiter-sized beaks.

  19. Hans-R

    Nice one. Cant wait until someone amatur takes an image that professionals havent been able to :)


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