Download site for Sun Spotter: http://fileol.com/education/sun-spotter-2.5.1.html
Today's sunspots from Sun Spotter.
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Sunday, November 13, 2011
Solar Arm Chair Observing
I usually consider looking at astrophotos fun, but a poor substitute for getting out and observing under the night sky. One exception for me is solar observing, which can be done in quasi-real time using Neal Monk's Sun Spotter software for the MAC or PC. This software makes real time SOHO images of the sun available at the touch of a button. I especially like the white light "Sunspots" button, because it gives me a view of the sun similar to what I see with my solar filter on my 80mm refractor. I have it set to run on startup, so I get to see what the sun looks like every time I restart my computer. During the day, I check the sun out periodically to see if anything interesting is happening that I might want to go outside and catch. Give this software a try. I think you'll like it.
Download site for Sun Spotter: http://fileol.com/education/sun-spotter-2.5.1.html
Download site for Sun Spotter: http://fileol.com/education/sun-spotter-2.5.1.html
Halos Around the Moon
For much of last week Israel from center to south was covered by high cirrus clouds containing ice crystals, also called diamond dust. These ice crystals refract light from the moon, especially a bright full or near-full moon, at a 22 degree angle from the source. The result is a halo around the moon that is sometimes white, sometimes rainbow colored if the moon light and ice crystals are just right. This can be a beautiful sight, but it also ruins the sky for star tours, since the scattered light of the moon blocks out all but the brightest stars.
Last week, the near-full moon was quite close to Jupiter, which was the only heavenly body still visible through the moon halo. For a brief time I could see a slight rainbow with the red on the inner part of the halo, but for the most part it was just a faint white ring. This week, skies are clear, at least for now, in Mitzpe Ramon.
Last week, the near-full moon was quite close to Jupiter, which was the only heavenly body still visible through the moon halo. For a brief time I could see a slight rainbow with the red on the inner part of the halo, but for the most part it was just a faint white ring. This week, skies are clear, at least for now, in Mitzpe Ramon.
This 22 degree moon halo was seen last Thursday, 11/10/11, from Mitzpe Ramon. The bright object to the right of the moon is Jupiter.
Tuesday, November 8, 2011
Spotted Sun
The largest sunspot group in the current solar cycle number 24 is now visible in the center of the solar disk. This group is so large that you could fit 22 earths inside of it. It is also large enough to be visible to the naked eye as a tiny black "beauty mark" on the surface of the sun. Such large sunspots are not that rare as we approach the solar maximum, however, this has been an unusually quiet run-up to the solar maximum, which was originally expected in 2012 and may now be delayed. So, large sunspots have been rare so far in solar cycle 24. Scientists have not seen such low sunspot numbers for over a century, and the solar magnetic field, which produces sunspots, is at the lowest strength seen in over 50 years. There is even some fear that we may be entering a period of low solar activity comparable to the Maunder Minimum of 1645-1715 when the sun was spotless for 70 years and a mini-ice age occured. I guess that would put the kabosh on Global Warming, though.
However, the sun has recently been much more active, showing many spots and especially larger ones. Ancient Chinese astronomers reported seeing naked eye sunspots, viewing the sun through thin clouds. This made me want to take up the challenge of seeing naked-eye sunspots, too. As we approach the solar maximum these will probably become more frequent, but not common.
How do you do this safely? First of all, NEVER LOOK AT THE SUN WITHOUT EYE PROTECTION MADE SPECIFICALLY FOR THAT PURPOSE. YOU WILL DAMAGE YOUR VISION. IF YOU USE ANY OPTICAL AID WITHOUT THE APPROPRIATE PROTECTION, YOU WILL GO BLIND INSTANTLY. DO NOT USE SOME CONTRAPTION YOU HAVE MADE YOURSELF, LIKE FILM OR SMOKED GLASS.
Now that we've gotten that out of the way, here is what you can do. A number 14 welder's glass is safe to use in front of your eyes for naked eye viewing. This is what I use. You can buy one at any welding supply store. They are easy to find in the US, but I don't know how easy they are to find in Israel. I buy my solar filters from Thousand Oaks Optical in the US and have been very happy with them. They not only make filters for naked eye use, but also for binoculars and other optics such as telescopes and cameras. Even very small optics can show a great deal of detail on the sun, which you can either photograph or draw. This also makes an interesting project for schools. Another method to view the sun is solar projection, where a pin hole or small optic is used to project an image of the sun on a screen, such as a piece of paper. Be careful if you use projection with a small optic like a binocular that you don't inadvertently shine it in someone's eye.
Here is an image of today's sun, showing the gigantic sunspot group in the center. It will take approximately 10 days for it to rotate out of sight, and who knows, it may be followed by another.
- by Ira Machefsky
However, the sun has recently been much more active, showing many spots and especially larger ones. Ancient Chinese astronomers reported seeing naked eye sunspots, viewing the sun through thin clouds. This made me want to take up the challenge of seeing naked-eye sunspots, too. As we approach the solar maximum these will probably become more frequent, but not common.
How do you do this safely? First of all, NEVER LOOK AT THE SUN WITHOUT EYE PROTECTION MADE SPECIFICALLY FOR THAT PURPOSE. YOU WILL DAMAGE YOUR VISION. IF YOU USE ANY OPTICAL AID WITHOUT THE APPROPRIATE PROTECTION, YOU WILL GO BLIND INSTANTLY. DO NOT USE SOME CONTRAPTION YOU HAVE MADE YOURSELF, LIKE FILM OR SMOKED GLASS.
Now that we've gotten that out of the way, here is what you can do. A number 14 welder's glass is safe to use in front of your eyes for naked eye viewing. This is what I use. You can buy one at any welding supply store. They are easy to find in the US, but I don't know how easy they are to find in Israel. I buy my solar filters from Thousand Oaks Optical in the US and have been very happy with them. They not only make filters for naked eye use, but also for binoculars and other optics such as telescopes and cameras. Even very small optics can show a great deal of detail on the sun, which you can either photograph or draw. This also makes an interesting project for schools. Another method to view the sun is solar projection, where a pin hole or small optic is used to project an image of the sun on a screen, such as a piece of paper. Be careful if you use projection with a small optic like a binocular that you don't inadvertently shine it in someone's eye.
Here is an image of today's sun, showing the gigantic sunspot group in the center. It will take approximately 10 days for it to rotate out of sight, and who knows, it may be followed by another.
Sunspot group 1339 at the center of the sun, the largest group yet in solar cycle 24.
A close-up of the right portion of the sunspot group taken by Alan Friedman in Hydrogen Alpha light, showing the magnetic field surrounding the group.
Friday, October 28, 2011
Jupiter at Opposition Tonight
Jupiter shines at magnitude -2.9 and shows a disk of 49.7 seconds of arc, just a fraction smaller than last year and as big as it has been since 1962. It is "just" 593.9 million kilometers, or 33.02 light minutes, distant. It seems to be huge in my 102mm refractor, with lots of detail showing in the cloud bands that cross the planet. The Galilean moons continue their dance around the planet, adding a charming note to the view.
The Danish astronomer Ole Roemer was the first scientist to use the varying distance of Jupiter at opposition and at conjunction to estimate the speed of light, using the timing of transits of Jupiter's moon Io in the 1670s. He came up with a speed of 186,000 miles per second, almost right on the money.
Make sure you take some time to go out and view the planet during this opposition. The 4 Galilean moons should be visible in even small binoculars, although probably not all at the same time. Through even a very small telescope all 4 Galilean moons are easily visible, together with a wealth of detail on the planet. The orbit of the moons around Jupiter was one of the pieces of evidence that Galileo cited in support of the then still controversial heliocentric theory of Copernicus over against the geocentric theory of Ptolemy and the theologians of his time. You can go out and observe this piece of evidence with your own eyes tonight. It doesn't get more exciting than that!
Position of a superior plant (beyond the orbit of the Earth) at opposition, as Jupiter is now, and at conjunction.
- by Ira Machefsky
Tuesday, October 25, 2011
Mooned out for the Draconids Meteor Shower
Did you go out and watch the Draconids on October 8th? There was a meteor storm predicted, with meteor rates in excess of 750 per hour. We were out at our observing location and counted only a disappointing 2 meteors from 8:30PM - 10:00PM. Our sky conditions were very poor. Not only was there a nearly full moon in the sky, but there was also a high, thin haze that spread the moonlight across most of the sky. We even had a hard time seeing second magnitude Polaris, the Pole Star. Others in Israel and beyond counted much higher numbers, their skies presumably not affected by haze. Better luck next time.
- By Ira Machefsky
A lone Draconid streaks across the October sky.
- By Ira Machefsky
Did you bet against Einstein? You lost!
As we foretold, the surest way to lose your money is to bet against Einstein. The hoopla over the discovery of neutrinos that allegedly (as they say of criminals) traveled faster than light (superluminal neutrinos) has died away, with only faint traces of pie left on the faces of the researchers at CERN, who forgot to take account of special relativity in timing the travel of the neutrinos between Geneva and Gran Sasso in Italy. The scientists at CERN used the highly accurate clocks in GPS satellites orbiting high above earth to synchronize their clocks in the laboratory. But they neglected to take account of the relative motion between their laboratory clocks and the GPS satellites, which accounted for a 32 nanosecond error in each direction of travel, almost exactly amounting to the 60 nanoseconds faster than light that the neutrinos were supposed to have traveled. Sic semper gloria mundi.
Neutrinos travelling between CERN in Geneva and Gran Sasso in Italy were mis-timed due to the relative motion between the two locations and GPS satellites in orbit above the earth.
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