This is Dudley Observatory’s Skywatch Line for Friday, February 24, through Sunday, February 26, written by Sam Salem.
On Friday, Sun rises at 6:39am and sets at 5:39pm; the waning crescent Moon rises at 5:23am and sets at 3:46pm. New Moon occurs on Sunday at 9:58am. The new Moon this Sunday leads to the first of two solar eclipses this year. Because the new Moon is far away to totally cover over the solar disk, an annular eclipse showcases a ring of sunshine encircling the new Moon silhouette. The annular solar eclipse is visible from southern South America and Africa on Sunday. The second solar eclipse this year is a total eclipse. It will take place on August 21. The total solar eclipse will be visible from a narrow corridor that goes through the USA and Canada. Unlike the annular eclipse, during a total solar eclipse the Moon comes close enough to Earth to totally cover over the solar disk. Both annular and total eclipses are central eclipse, whereby the new Moon swings directly in front of the Sun.
Jupiter will be 4 degrees north of Spica, the brightest star of constellation Virgo, on Friday morning. Jupiter rises at 9:25pm, reaching transit altitude of 40 degrees south at 3:04am. While Spica rises at 9:40pm, reaching transit altitude of 36 degrees south at 3:04am. Spica is a binary star, with two stars that are telescopically indistinguishable from a single point of light. The dual nature of this star was revealed by analysis of its light with a spectroscope, an instrument that splits light into its component colors. Both stars in the Spica binary system are larger and hotter than the Sun. Spica is the brightest star in the constellation Virgo, the Maiden, and it is the 15th brightest star visible from anywhere on Earth. It has the same brightness as Antares in the constellation Scorpius. Sometimes, Antares is listed as the 15th and Spica as the 16th brightest.
Mars lies just above Venus. Uranus lies 0.6 degrees south of Mars on Sunday. Mars appears significantly brighter than Uranus, however, you should still be able to see both in binoculars. A telescope will reveal more detail. Mars and Uranus set around 9:23pm.
Look for Arcturus, the brightest star in the constellation Bootes, to climb over eastern horizon. Arcturus reaches transit altitude of 55 degrees south around 7:24pm, on Sunday. Extend the arc of the Big Dipper handle to verify that you’ve found Arcturus. The Big Dipper doesn’t reach its high point for the night until an hour after the midnight hour. Arcurus will be sparkling above the horizon at dusk in late March to announce the return of spring.
World War II had an influence on the foundation of Radio Astronomy. It also had a direct impact on the history of solar radio observations. In February 26-27, 1942, an English radar station received a strong noise signal thought to be a new source of interference created by enemy transmitters. The strong noise signal was radio wave emissions from the Sun associated with a group of sunspots that appeared at that time. That same year, Dr. G.C. Southworth detected solar microwaves at wavelengths of 1 and 10cm, while he was working at the Bell Telephone Laboratories in New York.