Satellite photo of the August blackout along the East Coast and Great Lakes
The September sky 2003
In an earlier article, I reported that in the center of most large cities, only a dozen of the brightest stars were visible. The mid-August blackout allowed New Yorkers the opportunity to see many more stars than usual. With few lights, Vega and many dimmer stars were easily visible. Mars gave them a great early-morning show. Perhaps they even had a chance to glimpse the diffuse glow of the Milky Way. Hopefully they were able to get out, look up, and enjoy the beautiful sights that we often take for granted in rural, dark America. Just remember, we all need to work to keep our skies dark.
Even city dwellers will be able to spot the ten brightest stars in the sky. So, here are the first three in the list of the brightest ten stars in the sky listed by magnitude (smaller numbers are brighter).
Number 10: Betelgeuse—Magnitude 0.5
Even though Betelgeuse (pronounced “beetle juice” by most astronomers) is ranked at number ten, don’t let this fool you. Its actual brightness is tempered by its 430-light-year distance. This super-giant star is as bright as fifty-five thousand Suns. Betelgeuse can be found at the eastern shoulder of mighty Orion, the Hunter. Betelgeuse is a red super giant, 650 times the diameter and about fifteen times the mass of the Sun. If Betelgeuse were to replace the Sun, planets out to the orbit of Mars would be inside the star!
Number 9: Achernar—Magnitude 0.45
Achernar is derived from the Arabic phrase meaning "the end of the river," and is the southernmost star in the constellation Eridanus, the River. At a distance of 144 light years, this star is only slightly brighter then Betelgeuse as seen from Earth. This is a tough target for New Mexicans since it is on the southern horizon in the winter. Achernar is the hottest star on our list. Its temperature has been measured to be between 24,740 and 33,740 degrees Fahrenheit. Its luminosity ranges from 2,900 to 5,400 times that of the Sun. It is currently burning its hydrogen into helium and will eventually evolve into a white dwarf star.
Number 8: Procyon—Magnitude 0.4
Procyon is a member of the small constellation Canis Minor, the Little Dog. The constellation is the smaller of Orion’s two hunting dogs (Canis Minor and Canis Major). Only seven times more luminous than our sun, it appears so bright because it is only 11.4 light years away. Procyon is a main-sequence star, beginning the death process by converting its remaining core hydrogen into helium. Procyon is currently twice the diameter of the Sun, one of the largest stars within twenty light-years. Procyon is orbited by a white dwarf companion that was detected in 1896. Procyon B contains 60 percent of the Sun’s mass and is just one-third the size of Earth.
I can’t believe I’ve actually been writing this column for a year now. Many thanks to Ty and Barb for allowing me the opportunity to be a regular columnist and to the Signpost readers for reading what I write.