The Sun's angry red spot

By Phil Plait | March 15, 2012 7:00 am

The Sun has been in a bit of a mood lately, spitting out some pretty big flares (including the second largest one of the current magnetic cycle). Alan Friedman, one of my favorite astrophotographers, caught the culprit sunspot, Active Region 1429, as it was nearing the edge of the Sun on Monday:

Doesn’t look like your normal shot of the Sun, does it? [Click to ensolarnate.]

Alan uses an Hα filter, which cuts out almost all the light from the Sun except for a narrow slice of color emitted by warm hydrogen. This reduces the glare hugely, and reveals delicate structures in the Sun’s plasma. He then inverts the image, so bright things appear dark, and vice-versa. That’s an old astronomer’s trick that makes fainter things easier to see. He also used a false color palette to make it appear reddish. That’s actually a good idea, since the color of light emitted by the hydrogen is at 6563 Angstroms, right in the middle of the red part of the spectrum!

In this case, doing all this makes the Sun look like a 1970s shag rug. It’s a technique he uses to great effect. Just click on the Related Posts links below to see how!

Andf you’re wondering what the whole Sun looked like instead of just this closeup, then feast your eyes on this:


Yegads [click to embiggen]. Magnificent. Note all the prominences — giant towers of gas at the edge of the Sun — and the simply enormous filament of plasma at the top of the Sun’s disk. It’s about 400,000 km (240,000 miles) across: the distance from the Earth to the Moon!

Holy solar phenomena.

I’ll add that Mexican astrophotographer César Cantú also took a nice image of the active region, and caught a loop of material arcing from one spot to another (marked with arrows):

Beautiful!

And obviously, both Alan and César do a far better job of taking pictures of the Sun than I do.


Related Posts:

The face of our star
Giant sunspots are giant
For your viewing pleasure: Active Region 1302
The boiling, erupting Sun

CATEGORIZED UNDER: Astronomy, Pretty pictures

Comments (29)

  1. By Jove, its got Jupiter beat! ;-)

    Of course, that does depend on your point – and wavelength – of view. ;-)

    Has to be Hydrogen alpha making our Sun incardanine, turning the Yellow / White One red.
    Great images cheers. 8)

  2. Nigel Depledge

    These are some pretty cool pics!

    However, the BA said:

    . . . the color of light emitted by the hydrogen is at 6563 Angstroms, right in the middle of the red part of the spectrum!

    So, translating that for a 21st century audience – it’s 656.3 nm.

    BA, as far as I can tell, every scientist on the planet uses SI units for light wavelengths except those in the US (and X-ray crystallographers, but all that X-radiation will have had some effects so that’s understandable). Hell, even the weird units used for infrared spectrometry (wavenumber, in cm^-1) is SI. Please please please will you start using the SI.

    Also, if you’re going to insist on the use of Ångstroms, you should get the spelling right!

  3. Rick White in TX

    The image of the whole sun is just … WOW.

  4. Chris

    Is it just me or does that first picture look like a bird’s face, like an owl. Perhaps an Angry Bird?

    @2 Nigel
    Ångstroms are perfectly fine. 1 Å = 10^-10 m, not hard to memorize. The reason it’s used so often is because it’s a convenient unit. Atomic sizes are on the order of Ångstroms, yes that’s close to nm, but this way we don’t have to deal with the annoying decimal point.

    Next you’ll start saying stop using eV or ergs.

  5. WJM

    The whole sun image looks almost… biological.

  6. Victor

    If anyone has seen Ghostbusters 2, the red sun reminds me of the evil goo that the guys battle in that one.

  7. JMW

    …He then inverts the image, so bright things appear dark, and vice-versa. That’s an old astronomer’s trick that makes fainter things easier to see…

    Careful, Phil. You can’t use the word trick, or the sun-deniers will accuse you of falsifying data that the sun really exists.

  8. SkyGazer

    I was totally engrossed in your terrific story when I stumbled on “largest one of the current magnetic cycle”. No wonder wonder people panic nowadays in 2012.

  9. Tara Li

    Documenting your “tricks” when you massage data is fine – it’s when you massage the data, and then present it as raw data, that is problematic. Real scientists want to see not only your data, but what you did to it between it coming out of the measuring device, and your presentation of it.

  10. Cheryl

    The red picture looks like it has a face! And the image of the whole sun is absolutely incredible!

  11. So how long until this is cited as evidence that solar activity is responsible for the fact that The Year Without a Winter (at least here in Northeastern Pennsylvania) has suddenly become The Year Without a Spring? (We’re on out third day of Summer-like weather.)

  12. Lintman

    Imagine the size of the sperm that would fertilize that egg!

    (Compare sun photo to SEM picture here: http://www.visualphotos.com/image/1×7548777/human_egg_cell_and_sperm_cells_esem)

  13. Sir Craig

    I have to agree with WJM on this one: When I first viewed the larger complete image, it struck me how biological the sun appeared. Perhaps this shouldn’t be a surprise, as much of our biology is beholden to the sun, but it still kinda freaks me out to see it AS biological.

    Great pics.

  14. KCS

    Reminds me of the monster of the ID from Forbidden Planet

  15. Doug Richardson

    “Old astronomer’s trick”

    Is it a trick used only by “old” astronomers; or
    is it “an old trick” used by astronomers?

    Shouldn’t it be:
    “…astronomers’ old trick…”?

  16. Hi Phil,

    I’m a keen reader of your blog. THANKS for the awesome writing!

    For all sungeeks out there: here’s a fabulously cool interface to SDO data:

    http://timemachine.gigapan.org/wiki/SDO
    “GigaPan Time Machine enables simultaneous exploration of space and time across massive datasets that could not previously be interactively explored at full spatial and temporal resolution. The architecture we have implemented on our servers scales easily to far greater resolution than the current five examples demonstrate.”
    The view in 171A of the lower left quadrant, the filament activity: Woah!!!

    It seems to work much better in Chrome than in Safari. YMMV.

  17. Awesome photos. So excited about the Sun right now.

    But… another vote for SI units.

  18. Nigel Depledge

    Chris (4) said:

    Ångstroms are perfectly fine. 1 Å = 10^-10 m, not hard to memorize.

    That is not at issue. It’s a question of observing the relevant scientific convention. The Ångstrom is obsolete in all fields of science except X-ray crystallography.

    The reason it’s used so often is because it’s a convenient unit. Atomic sizes are on the order of Ångstroms, yes that’s close to nm, but this way we don’t have to deal with the annoying decimal point.

    It’s no more or less convenient than the nm, but the nm has two advantages in this context – (a), it is SI, and (b) it is the conventional unit for UV / visible wavelengths.

    And if you find the decimal point annoying, then you should get out of any field that involves quantitation. The decimal point in this case arises only because of the number of significant figures chosen. If Phil had cited the wavelength to 3 sig figs, then it would be an integral number of nm. Similarly, if Phil had cited the wavelength to 5 sig figs, there would be a decimal point when using Ångstroms, too.

    Next you’ll start saying stop using eV or ergs.

    I won’t say to stop using eV, because it is a conventional unit and happens to be derived from the combination of a universal constant (the charge on an electron) with an SI unit (the Joule per Coulomb, or Volt).

    However, the erg has not been a conventional unit for many years. It is an obsolete unit. AFAIAA, the Joule and th eV have been the only acceptable units for energy in a scientific paper for a number of decades. I find it particularly irritating when the BA cites energy in ergs, because I have no idea how large or small the number really is without looking it up.

    How would you feel, for example, if instead of ergs he used BTU for energy?

  19. Morris Maynard

    All this squabbling over SI/Ångstroms seems pretentious and silly. Either unit is equally clear in this context. And if you need to use the value in a formula, the conversion (either way) is so trivial as to be unremarkable. As long as you are not using Imperial units for wavelength, it’s all good so just enjoy the pretty photos, OK?

  20. Nigel Depledge

    Morris Maynard (25) said:

    All this squabbling over SI/Ångstroms seems pretentious and silly.

    What, so the concept of international scientific conventions about what units people use for various properties are “pretentious and silly”?

    When did that happen?

    Either unit is equally clear in this context.

    Not so, because the nanometre is the conventional unit for UV / visible light wavelengths, and the Ångstrom only lingers on in a different field of science.

    And if you need to use the value in a formula, the conversion (either way) is so trivial as to be unremarkable.

    True, but beside the point. Using SI units requires no conversion except in groups of three powers of ten (which are covered by the prefix system).

    As long as you are not using Imperial units for wavelength

    What, so you think the use of unconventional units doesn’t matter as long as you use the right unconventional unit? Have you ever heard of William of Occam?

    it’s all good so just enjoy the pretty photos, OK?

    Hey, it’s my FSM-given right to nitpick. No-one said you had to join in.

  21. Chet Maunder

    11: You’re right. Just wait ’till those CRAZY people who think the Sun has something to do with the weather get hold of these pictures! They’re CRAZY!

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