Starship Asterisk*

Large Sunspots Now Crossing the Sun

Explanation: One of the largest sunspot regions in recent years is now crossing the Sun. This region of convoluted magnetic fields may well produce a solar flare that releases a cloud of energetic particles into the Solar System. Were a very powerful cloud to impact the Earth's magnetosphere, it could be dangerous to Earth-orbiting astronauts and satellites. Conversely, the impact of even a less energetic cloud might create picturesque aurora. Pictured above is the sunspot region as it appeared two days ago. The rightmost part of this region has been cataloged as AR 11785, while the left part as AR 11787. The darkest sunspot regions contain nearly vertical magnetic fields and are called umbras, while the surrounding bronze regions -- more clearly showing stringy magnetic flux tubes -- are called penumbras. Churning solar granules, many about 1000 km across, compose the yellow background region. No one knows what this sunspot region will do, but space weather researchers are monitoring it closely.

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Man, Where did I put my shades??? Ah...there...better...
Wow, what a nice clear picture of a Sunspot. Looks like a painting!!! Another PEACH of a view!!!
We should call the largest at the right...."The Big Foot Sunspot". No wonder it is a very hot Summer here so far....on to Solar Maximum!!!!

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are there sun spots on the directly opposite side of solar sphere ?? some sources hold that suns spots occur in pairs each directly opposite the other on the solar sphere suggesting magnetic activity on a mega scale. such occurance does not seem to be well documented and supported by evidence.

Are Sunspots black because they're some kind of bottomless pit on surface of the Sun? Or, are they black simply because they don't emit light in the visible light spectrum? That being the case, are they bright at some particular wavelength?

Bergerac wrote:are there sun spots on the directly opposite side of solar sphere ?? some sources hold that suns spots occur in pairs each directly opposite the other on the solar sphere suggesting magnetic activity on a mega scale. such occurance does not seem to be well documented and supported by evidence.

No. Sunspots are local events that do not correlate with any spots on the opposite side of the Sun. They do tend to appear in pairs, but those paired spots are adjacent to each other.

zbvhs wrote:Are Sunspots black because they're some kind of bottomless pit on surface of the Sun? Or, are they black simply because they don't emit light in the visible light spectrum? That being the case, are they bright at some particular wavelength?

Sunspots aren't black. They are blindingly bright in the visible spectrum. They only appear dark in comparison to the even brighter regions surrounding them. They are regions that are a little cooler, and therefore a little dimmer. If you expose an image to show detail in the area surrounding a sunspot, the spot itself is underexposed. If you expose for detail in the spot (which you can certainly do) the surrounds are overexposed. If you look closely at today's image, it is clear that sunspots emit light, because all sorts of detail can be seen in them.

I think of sunspots like looking into someone's apartment window from the outside during a bright day. It looks black and it is hard to see anything inside but if you go inside then it's not dark at all.

Fascinating image and we usually learn more about the APODs by reading the discussion.

I am a fan of the astronomical illustrations of E. L. Trouvelot, a 19th century astronomical observer and illustrator. Check out his drawing entitled "Group of Sunspots and Veiled Spots" which is based on observations he made in 1875. It is amazing how this illustration compares to the best photos of sunspots today.

http://digitalgallery.nypl.org/nypldigi ... _id=443329

John Erickson wrote:I am a fan of the astronomical illustrations of E. L. Trouvelot, a 19th century astronomical observer and illustrator. Check out his drawing entitled "Group of Sunspots and Veiled Spots" which is based on observations he made in 1875. It is amazing how this illustration compares to the best photos of sunspots today.

http://digitalgallery.nypl.org/nypldigi ... _id=443329

The solar prominences are very well done, as well!

Chris Peterson wrote:

zbvhs wrote:Are Sunspots black because they're some kind of bottomless pit on surface of the Sun? Or, are they black simply because they don't emit light in the visible light spectrum? That being the case, are they bright at some particular wavelength?

Sunspots aren't black. They are blindingly bright in the visible spectrum. They only appear dark in comparison to the even brighter regions surrounding them. They are regions that are a little cooler, and therefore a little dimmer. If you expose an image to show detail in the area surrounding a sunspot, the spot itself is underexposed. If you expose for detail in the spot (which you can certainly do) the surrounds are overexposed. If you look closely at today's image, it is clear that sunspots emit light, because all sorts of detail can be seen in them.

While Venus was transiting across the Sun's face last year, there were a number of sunspots on the Sun as well. Observing the transit with a small telescope and a white-light solar filter, I could clearly see that Venus was a black silhouette, and that while the sunspot umbras were dark compared to the rest of the Sun's surface, they were significantly brighter than Venus. If you want to try this for yourself, there will be another pair of transits of Venus in 2117 and 2125.

.

Ms. Hearingaid wrote:
I think of sunspots like looking into someone's apartment window from the outside during a bright day. It looks black and it is hard to see anything inside but if you go inside then it's not dark at all.

Art (a genius or insane ) Neuendorffer

The surface around the sunspots look like a farm field of mud which has been dried out during a drought. What the sun needs is a good rain.

LocalColor wrote:Fascinating image and we usually learn more about the APODs by reading the discussion.

Yes .. and we learn that some posters here go around peering into people's apartment windows (it works better with infrared glasses Geck)

neufer wrote:Art (a genius or insane ) Neuendorffer

Given your propensity for off-topic associations, I'd go with insane. However, later on it is revealed that Pinky is actually much more of a genius than Brain. So, both, maybe.

neufer wrote:Art (a genius or insane ) Neuendorffer

YES! DEFINITELY

I think the temperature of a sunspot is about 4,000 Kelvin. That is quite similar to the temperature of a typical red giant. So if you want to know what a red giant looks like compared with the Sun, take a look at what sunspots look like compared with the rest of the face of the Sun!

Ann

Ann wrote:I think the temperature of a sunspot is about 4,000 Kelvin. That is quite similar to the temperature of a typical red giant. So if you want to know what a red giant looks like compared with the Sun, take a look at what sunspots look like compared with the rest of the face of the Sun!

Ann

I don't think that sunspots give us a good idea of what a red giant star would look like close up. We see sunspots against the background of the brighter surface of the Sun. We would be looking at a red giant against the perfect blackness of space. If you've ever seen a Moon rock close up, it's about as dark as asphalt, but the Moon gleams white in contrast with space.

Organic Farmer wrote:
we learn that some posters here go around
peering into people's apartment windows

(it works better with infrared glasses Geck)

• Not unless the windows are made out of rock salt:

http://en.wikipedia.org/wiki/Greenhouse_effect#Real_greenhouses wrote:
<<It has also been demonstrated experimentally (R. W. Wood, 1909) that a "greenhouse" with a cover of rock salt (which [unlike glass] is transparent to infra red) heats up an enclosure similarly to one with a glass cover. Thus [actual] greenhouses work primarily by preventing convective cooling.>>

Anthony Barreiro wrote:I don't think that sunspots give us a good idea of what a red giant star would look like close up.

I don't think that's what Ann was suggesting. Only that the brightness and color of a sunspot is similar to that of a red giant- which is obviously still very bright.

Is there an AR 11786 or has it gone now . If it is still there then is it the sunspot area between AR 11785 and AR 11787 . Sunspots are visually .

In the explanation it states the image shows "the sunspot region as it appeared two days ago" which, based on the date of the APOD, would thus be 2013 July 8. However, in the version brought up through the "Picture above" link (and also when clicking on the APOD image when online) it has on that version "2013-07-06" which will presumably mean that the date it was taken was 2013 July 6 (it surely cannot be 2013 7 June). I'm (nothing new there though ).

The other day NBC lost New Hampshire. http://www.youtube.com/watch?v=2m1c_mzoZN0 I think it's been found! Probably a little bigger. Ron

Someone in their graphics department musta had a 'mind spot' going across their brain. I'll bet they felt really

I am puzzled by this statement: "This region of convoluted magnetic fields may well produce a solar flare that releases a cloud of energetic particles into the Solar System." My understanding of flares is that they are regions of very high energy (M, X class etc), but that CME's are the eruptions of plasma (energetic particles). Both of course are results of magnetic field contortions. I have read that a flare can be associated with a CME, or not, and vice versa. But that a flare itself, doesn't release a cloud of energetic particles (plasma). Could you clarify please? Thank you!