Archives for the 'Sun' Category
The 23rd Cycle’s Last Gasp?
Published on 28 Mar 2008 at 12:05 pm.
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Filed under Sun.
The Sun goes through a cycle of sunspot activity that lasts about 11 years. It isn’t an exact period, sometimes it is a little short, say 10 years, and sometimes a little long, as in 12 years. These sunspot cycles have been studied continuously for nearly 250 years. The Sun just started […]
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The 24th Cycle
Published on 6 Jan 2008 at 8:03 am.
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For the earliest days of telescopes, astronomers have known that the Sun has spots. But, the number of sunspots is not constant. Individual spots come and go. In 1843, Heinrich Schwabe noted that the number of sunspots seems to go through a pattern that lasts a bit over a decade. The […]
The Voyagers and the Heliosphere
Published on 13 Nov 2006 at 5:42 pm.
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Filed under Sun, interstellar medium.
Far from the Sun, two tiny spacecraft sail onward heading out of the Solar System into interstellar space. Voyager 1, is now a distance of just about 101 Astronomical Units from the Sun, and Voyager 2 is over 81 Astronomical Units out. Both spacecraft were launched in 1977 to study the outer planets of our Solar System. […]
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Watching the Mercury Transit
Published on 8 Nov 2006 at 10:44 am.
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Filed under Sun, planets, skywatching.
Don’t forget! Mercury will transit the Sun today. You can read my earlier post on the transit to find out more about it. While not a once in a lifetime opportunity, it is still rare enough that you should go take a look.
However, remember that looking at the Sun is dangerous if you don’t know […]
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STEREO on the Sun
Published on 26 Oct 2006 at 7:41 pm.
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Filed under NASA, Sun.
Last night, October 25, a Delta II rocket lifted off from Pad 17B at the Cape Canaveral Air Force Station.  It was carrying twin NASA spacecraft on a mission to study our nearest star, the Sun.  The acronym selected for this mision is STEREO (standing for Solar Terrestrial Relations Observatory), and it is quite aprospos because these […]
Holding the Sun up
Published on 7 Oct 2006 at 7:57 pm.
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The other day, someone asked me where the Sun’s energy comes from. Well, the simple answer is that it comes from nuclear fusion in its core. But, as with all things, real life is a bit more complicated. How does energy get into the Sun so that nuclear fusion can release it? […]
The Death of the Sun
Published on 5 Jun 2006 at 1:24 pm.
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The Sun is dying. Oh, it won’t happen tomorrow, or the next day, but it will happen. Nothing lasts forever. Despite what the ancients believed, the heavens are not unchanging and eternal.
Currently, the Sun is sort of stable. It maintains this stabilty through energy releaed in nuclear fusion in its core. This energy ballances the […]
