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Regulus Occulted
| Title |
Regulus Occulted |
| Explanation |
On May 21, viewed from the continental US, a star winked out as it passed behind the dark limb of the first-quarter Moon [ http://www.inconstantmoon.com/index.htm ]. The star, Regulus [ http://www.astro.wisc.edu/~dolan/constellations/hr/3982.html ], is hotter than the sun, about 69 light-years distant, and shines in Earth's skies as the brightest star in the constellation Leo [ http://www.astro.wisc.edu/~dolan/constellations/constellations/ Leo.html ], the Lion. The Moon [ http://nssdc.gsfc.nasa.gov/planetary/lunar/moon_tree.html ] is the brightest object in the night sky [ http://home.cwix.com/~pam.orman@cwix.com/JoeMoon.html ] and is less than 1.5 light-seconds away. As illustrated in this multiple-exposure photograph, such lunar occultations [ http://www.skypub.com/sights/occultations/occultations.shtml ] of bright stars can be majestic to watch. Their exact timing depends on the observer's location but they are not particularly rare occurrences. Astronomers can use lunar occultations to help map [ http://antwrp.gsfc.nasa.gov/apod/ap980911.html ] the surface of the Moon [ http://www.seds.org/nineplanets/nineplanets/luna.html ]. |
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Solar corona photographed fr
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| Title |
Solar corona photographed from Apollo 15 one minute prior to sunrise |
| Description |
The solar corona, as photographed from Apollo 15 about one minute prior to sunrise on July 31, 1971, is seen just beyond the lunar horizon. The bright object on the opposite side of the frame is the planet Mercury. The bright star near the frame center is Regulus, and the lesser stars form the head of the constellation Leo. Mercury is approximately 28 degrees from the center of the sun. The solar coronal streamers, therefore, appear to extend about eight degrees from the sun's center. |
| Date Taken |
1971-07-31 |
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