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Space Science

The Quietest Sun 227

Posted by kdawson
from the storms-a-comin' dept.
Orbity sends in a Boston Globe report on the unusual calm on the surface of the sun. The photos, many taken in more active solar times, are excellent — see the sequence from last year of a coronal mass ejection carrying away the tail of a comet. "The Sun is now in the quietest phase of its 11-year activity cycle, the solar minimum — in fact, it has been unusually quiet this year — with over 200 days so far with no observed sunspots. The solar wind has also dropped to its lowest levels in 50 years. Scientists are unsure of the significance of this unusual calm..." As if to be contrary, New Scientist mentions that the number of sunspots seem to be increasing.
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The Quietest Sun

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  • by Anonymous Coward on Tuesday October 14, 2008 @03:41AM (#25365913)

    such a welding shield / using welding goggles is also recommended for watching solar eclipses, so I guess you could go with it (oh, an equivalent is a shard of glass smoked over a fire...). preferably aim indirectly, using an LCD screen and a mirror so you don't have to look in the direction of the sun directly; then it will only be a matter of exposure time. even if the welding screen is too strong (those things are incredibly dark, you cannot see through them without a very powerful light source; just don't use one with automatic shielding that only gets dark when there IS such a source, I don't know if it works with direct sunlight alone), a longer exposure time should still get a good picture.
    (theoretically with a very short exposure you could also shoot a picture of the sun without any protection... do no try at home?)

  • by Suddenly_Dead (656421) on Tuesday October 14, 2008 @03:52AM (#25365955)

    The best way to do it is with a solar telescope, which will get you a nice, zoomed-in shot. Alternatively, you can buy solar filters for telescopes, but you must be absolutely positive that they are high quality and you must have one that covers the main telescope aperture; those that cover only the eyepiece are dangerous as fuck.

  • Cycle 24 spot seen (Score:3, Informative)

    by Anonymous Coward on Tuesday October 14, 2008 @04:20AM (#25366053)

    This story is a little late. Since then a cycle 24 spot group has been seen. Even so, solar activity is still rather low, cycle 24 is late. What does it mean? It means we're going to be in for some very cold weather in the near future.

    http://wattsupwiththat.com/2008/10/11/significant-cycle-24-sunspot-group-emerges/#more-3635

  • by ultranova (717540) on Tuesday October 14, 2008 @04:25AM (#25366079)

    Alternatively, you could simply project the image from the telescope to a piece of paper/cardboard and photograph that. That way there's no chance of filter failure, because there is no filter.

  • Re:I know what's up. (Score:1, Informative)

    by Anonymous Coward on Tuesday October 14, 2008 @04:54AM (#25366201)

    its a Dads' Army joke

  • by Zocalo (252965) on Tuesday October 14, 2008 @04:58AM (#25366211) Homepage

    The welder's glass will do at a pinch although it's not really sufficient for prolonged viewing of the sun. You'll also need to figure out some means of fixing it to the camera and you might find that it causes some unusual colour shifts in the image as well. Alternatively, you can get hold of a neutral density filter specifically designed for solar-photography; typically these will equate to about 10-15 stops of light loss - Cokin's NDX is one of the "cheapest" options, but that's relative; these are niche products that can be quite hard to find and are priced accordingly.

    As to composing and focusing without damaging the sensor or your eyes... Well, it's a good idea to be quick. :) Assuming you gave a "proper" DSLR with a through the lens viewfinder, then you can use the old trick of holding a piece of card a few inches from the eyepiece for basic composition, and on newer models you can also use the live preview screen function. Be aware though that when using the latter method your sensor will be exposed to the sun, so don't take too long or your sensor may get damaged. Focussing isn't too critical; set the camera to manual focus and focus on infinity before you start, and you should get a perfectly usable result, although for pin sharp shots of sunspots a little more precise focussing may be required. Typically, my approach is as follows:

    1. Set up the camera & lens (manual focus, filter attached, pointed in the right direction, etc.)
    2. Visually look for any sunspots by composing with the piece of card technique then focussing manually to make the image sharp; if there are any then I want to know where they are so I can make sure that they are sharp
    3. Compose the shot
    4. Reset the focus to infinity (it will be slightly off from step #2)
    5. Switch to live view
    6. If there are any sunspots, zoom the live view screen in where they are and focus until sharp
    7. Take the shot
    8. Profit! (hopefully)

    Be aware that with longer focal lengths the sun will move fairly rapidly across the viewfinder, but unless you are using an insanely long telephoto lens or a telescope with an adapter then this shouldn't be a major problem if you leave room for the sun to move across the frame when you compose.

    Good luck, and don't take any chances with your eyes!

  • by cheekyboy (598084) on Tuesday October 14, 2008 @05:59AM (#25366477) Homepage Journal

    Dont people google any more?

    Google answers all of you questions just ask, its like the oracle , it sees all, knows all, its your friend. Google just needs a 3d avatar, and a voice of Hal.

  • by lamapper (1343009) on Tuesday October 14, 2008 @06:41AM (#25366621) Homepage Journal
    I should have said know allot...oh well here is some additional information for those seriously interested:

    I am by no means an expert, much less an advanced knowledgeable person when it comes to this stuff, I just find it interesting and hope some of you will as well.

    I read an article over a year ago about how they could not get good measurements of solar flares because the instruments were not good enough and to get some measurements you needed at least two observation points some distance apart. (probably related to measuring gamma rays) It is my understanding that the earth finally has the right kinds of instruments up there to get very accurate measurements of the sun, solar flares and etc.... I searched around and have provided a few links. I believe you will really like the Youtube video, very cool. Enjoy!

    The Solar/SMO [wikipedia.org] was planned for 2003 and was finally launched on February 7, 2008. It is designed to measure solar radiation with wavelenghts from 200 nanometers - 100 micrometers. This covers the near-ultraviolet, visible and infrared areas of the spectrum. Here is NASA on Solar / SMO [nasa.gov].

    Hinode [wikipedia.org] launched in September 2006 has a three year mission to explore the magnetic fields of the sun. Specifically the investigates the interaction between the Sun's magnetic field and its corona. A consortium including Japan, US, UK and Norway worked together to measure the effects of "magnetic fields thought to be the source of solar flares" Three instruments are used, they are the SOT (Solar Optical Telescope, the X-Ray Telescope (XRT), and the Extreme Ultraviolet Imaging Spectrometer (EIS). The first images were captured on October 28.

    HESSI renamed RHESSI [nasa.gov] launched on February 5, 2002, captures solar flares, X-rays and gamma ray flashes. Prior to the launch of RHESSI, we only had the GOES spacecraft which only measured X-ray flux and to classify the size of solar flares. YouTube on HESSI / RHESSI; A solar flare [youtube.com] video - no sound. Here is a great video [youtube.com] that shows the various instruments in action, one right after the other. From 10/18/03 through 11/07/03; AR 10486 & AR 10488.

    From the Wiki,

    The most powerful flare of the last 500 years is believed to have occurred in September 1859: it was seen by British astronomer Richard Carrington and left a trace in Greenland ice in the form of nitrates and beryllium-10, which allow its strength to be measured today (New Scientist, 2005).

    Prior to the above launches, the Ulysees was pretty much it for measuring from space, before Ulysses there was only observations from the ground.

    Ulysses (17 year mission) [wikipedia.org] - was equipped with instruments to characterize fields, particles, and dust, and was powered by a radioisotope thermoelectric generator (RTG). Launched in 10/6/90 through 7/1/08; through "through triangulation (or, more specifically, multilateration). Each spacecraft has a gamma-ray detector, with readouts noted in tiny fractions of a second. By comparing the arrival times of gamma showers with the separations of the spacecraft, a location can be determined, for follow-up with other telescopes. Because gamma rays travel at the speed of light, wide separations are needed." Additional discoveries: Additional discoveries: [15] 1) Ulysses discovered that the Sun's magnetic field interacts with the Solar system in a more complex fashion than previously believed. 2) Ulysses discovered that dust coming into the solar system from deep space was 30 times more abundant than previously expected.

  • Re:I know what's up. (Score:5, Informative)

    by Kagura (843695) on Tuesday October 14, 2008 @07:12AM (#25366755)
    Holy cow. Misplaced comment here, but if you do not normally click the links in Slashdot articles, click them today. The first link [boston.com] has pictures of the sun that I never knew we had. They're amazing. Some of them are close up at 70km resolution. Just awesome.
  • by Anonymous Coward on Tuesday October 14, 2008 @07:43AM (#25366913)

    I should have said know allot

    No, you shouldn't have said that. "Allot" means to distribute or apportion. What you should have said in your first post was: "we should know much more then we do today.", though most people would say "we should know a lot more then we do today."

    HTH. HAND.

  • by Anonymous Coward on Tuesday October 14, 2008 @09:33AM (#25367821)
    Bad idea. For standard off the shelf telescopes, the internals, especially the main mirror are not designed to deal with the radiative heat from the sun. Doing as you propose, you risk warping the mirror or damaging other parts in your telescope.
  • by slash.duncan (1103465) on Tuesday October 14, 2008 @09:48AM (#25368025) Homepage

    OK, I appreciate all that info you posted and probably wouldn't have mentioned this were it not that your correction missed it too, but as someone who appreciates someone pointing it out to me, let me pass on this favor to someone obviously bright enough to make use of it.

    Think allot > allotment. "Allot" has its roots in the way possibly contested assignments (of land, jobs, whatever) were often distributed "in times of lore" and occasionally still are, using the process of drawing lots http://en.wikipedia.org/wiki/Drawing_of_lots [wikipedia.org]. Today, it has a broader meaning of distribution in general, whether by random means or not.

    "A lot" (two words) is a description of degree, meaning "very much", "a great deal". Even in the two-word form, however, until recently it was considered a colloquialism, unfit for formal use, altho (deliberate (mis)spelling) modern dictionaries seem to omit that, meaning it has graduated to being permissible in formal use only in the last few years. Taking its place has been the single-word form, "alot", which still causes many to shudder and can't be found in many dictionaries, but has come into increasingly common informal usage. Wictionary has this to say about the single-word-form "alot": "When it appears intentionally in print, it is generally either representing the original spelling in a work quoted, or is an attempt by the author to convey poor education in the character using it." Wictionary has more on the word, here: http://en.wiktionary.org/wiki/alot [wiktionary.org].

    From personal observation, "a lot" of the misuse of "allot" came about due to spell checkers flagging "alot", dumbly suggesting "allot" but failing to suggest "a lot", either because it's two words or because the term has only recently been accepted for formal use and thus didn't appear. I know this was the case for my personal misuse, as I never /did/ think "allot" looked right, but sometimes accepted it as the only plausible suggestion, without bothering to look it up. Only after seeing a reply such as this one did I realize my error and correct my ways. Fortunately or unfortunately, it also sensitized me to the word, such that seeing either "allot" used improperly, or "alot" used at all, causes me to shudder.

    So obviously, your usage "no allot" (I have a hard time writing it even quoting, now, as my fingers just want to do the right thing! ) was doubly wrong, thus the AC's WTF which I'm sure a lot of others thought as well. Then you corrected the no > know, but /still/ skipped the allot > "a lot", while providing a wealth of very interesting information in the same post so obviously you're intelligent enough, which /must/ mean you weren't aware of the problem at all, thus this post, hoping to correct that oversight. As I said, I'm simply passing on the favor, as I learned about the difference myself from just such a post.

  • by BigBlueOx (1201587) on Tuesday October 14, 2008 @10:07AM (#25368325)

    Good luck, and don't take any chances with your eyes!

    ...and while contemplating the photography of the Sun let's all take a minute and think about what happens when we bring the Sun's light to a focus. Like, say, using a magnifying glass to focus the Sun's light on an ant.

    Now think about what happens to the air/glass/coatings/electronics in your eyepiece/camera CCD/eyeball. Think real hard. Think, think, think.

    Please, please, please use a real solar filter over your camera's lens - a real solar filter from Orion or another supplier - over the main aperture only!! There have been cases of misbegotten souls who didn't think, think, think about magnifying glasses and ants and who used an eyepiece filter on their telescopes to view the Sun. Their eyepieces exploded. Yes, exploded. Rapidly heating the air inside a closed container like an eyepiece will cause that effect. The lucky ones didn't have glass shoot into their eyes.

    Not only do you have just one set of eyes but I'll bet you'd be one pissed puppy if your solar photography experiment resulted in a burned-out CCD or exploded viewfinder in that DSLR of yours.

  • Re:Very convenient (Score:2, Informative)

    by DougF (1117261) on Tuesday October 14, 2008 @10:24AM (#25368609)
    From what we can discern about sunspots so far it seems that a fair amount of solar wind is generated from the edges of sunspots. So, more sunspots = more solar wind. Now, the trick is to tie that increase in solar wind to an increase in energy imparted to Earth's atmosphere and somehow come up with a mechanism to transfer that energy to the troposphere... So far, only one or two serious climatologists think this might be happening, the other 99% are "sure" that it's not possible and CO2 is the primary culprit in global warming. However, 50 years ago, the theory of plate tectonics was "crackpot" by 99% of all geologists, too. There is a coincidence between rising numbers of sunspots and the global warming phenomenon. I don't know if the two are correlated, but they match near perfectly. If you average the 3-year peaks of sunspot activity in each cycle, there is a 67% increase in the mean number of sunspots post 1956 (Cycle 19). In other words, there aren't any longer or more cycles, but there are more sunspots per cycle than any time in recorded history. Another coincidence was the Maunder Minimum where the Earth had the Little Ice Age during a time of no or few sunspots. Correllating the two will take a lot of study (and abuse from climatologists and CO2 supporters), but good science requires we investigate the outlying data points as well as the primary suspects. 2008 is unusual because of the few sunspots (215 sunspot-free days so far). But, that doesn't mean instant global cooling, nor does it indicate a trend with the Sun. For all we know, there are hundred and thousand-year cycles going on in the Sun that we've not had time to see or study and this lull is just a blip before another onslaught. Or, it could be a start of another Minimum (I'd like it named after me, please), in which case get out the arctic gear. In other words, if that gigantic lightbulb 1.3M times the size of the Earth we call the Sun, and parked only 94M miles away is the primary culprit for global warming, we have no control so you might as well crack open a beer, sit back, and enjoy the ride...
  • New spots are beginning to break out on the face of the Sun and may signal the end of a dry spell in solar activity.

    For which I, as a radio amateur [calum.org] will be very happy, as we're currently right at the lowest point of the sunspot cycle [wikipedia.org] . The sun's activity correlates with the "reflectivity" of the layers of the atmosphere. When the layers are "reflective", signals can bounce [wikipedia.org], with each bounce landing a thousand or so miles away. If you get a few bounces, you can talk to the other side of the world, even on low power. When there's no propagation [wikipedia.org], you are unlikely to get more than 50 or so miles (groundwave), no matter how much power you pump out (excluding modes like satellite, moonbounce, meteorscatter, etc).

    Although the solar dials [rice.edu] don't seem to indicate it.

  • It's not "degrees K" (Score:3, Informative)

    by sootman (158191) on Tuesday October 14, 2008 @10:55AM (#25369101) Homepage Journal
  • by Anonymous Coward on Tuesday October 14, 2008 @11:06AM (#25369287)

    There's a sunspot going on today: http://sohowww.nascom.nasa.gov/sunspots/

    What about this beautiful solar prominence on october 10: http://sohowww.nascom.nasa.gov/pickoftheweek/

  • by Mr. Slippery (47854) <(tms) (at) (infamous.net)> on Tuesday October 14, 2008 @12:49PM (#25370849) Homepage

    no it won't protect your eyes.

    Welder's glass of the right type will indeed protect your eyes, as will a few other types of filters. This site [nasa.gov] has good information.

    The Sun is not the face of God. It is very bright and can damage your eyes, but sufficient filtering will reduce the brightness and allow direct viewing.

    When we had an annular eclipse in, IIRC, 1994, I stacked a whole bunch of sunglasses together and took a quick look, with no damage.

  • by defnoz (1128875) on Tuesday October 14, 2008 @12:53PM (#25370901)

    No, you shouldn't have said that. "Allot" means to distribute or apportion. What you should have said in your first post was: "we should know much more then we do today."

    No, you shouldn't have said that either. You should have said "we should know a lot more than we do todday."

    HTH. HAND.

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