THE SOUTHWORTH PLANETARIUM
207-780-4249 www.usm.maine.edu/planet
70 Falmouth Street Portland, Maine 04103
43.6667° N 70.2667° W
Founded January 1970
"The ultimate in outside!"207-780-4249 www.usm.maine.edu/planet
70 Falmouth Street Portland, Maine 04103
43.6667° N 70.2667° W
Founded January 1970
tomorrow morning, it won't linger long in the pre-dawn sky. It will be more flickering flame than rising star. Yet, after a two month absence its fleeting appearance in our sky will delight those myriad sky watchers who've yearned for its return. Although Betelgeuse's arrival ominously portends winter's eventual return, we are gladdened by the latest renewal of the next 10 month Betelgeuse cycle.
Betelgeuse represents Orion's eastern shoulder. Betelgeuse is a red super giant large enough to accommodate more than 160 million Sun-sized spheres. (Image: Wikipedia)
Betelgeuse's "heliacal rising" date for this latitude is July 21st. This means that an observer watching the eastern pre-dawn sky on this date will be able to observe Betelgeuse rise above the horizon just before the intensifying morning twilight absorbs it. The star's "heliacal setting" date was May 21st. On that evening, an observer looking toward the western evening sky can see Betelgeuse in the evening twilight for a moment before it sets. On the following evening, Betelgeuse will not be visible. By the time the sky darkens enough to render Betelgeuse visible, it will have already set.
As is true with all non-circumpolar stars (those stars that actually rise and set), Betelgeuse rises four minutes earlier each day as a consequence of Earth's revolutionary motion. Though Betelgeuse will grace us with a cameo tomorrow morning, it will be visible for about five minutes on the following morning and about nine minutes the next morning. Betelgeuse is rising earlier and, as its summer, the Sun is rising slightly later each morning. By early August, Betelgeuse will be up for viewing for about half an hour.
Betelgeuse, like its host constellation Orion, is most prominent in the winter, when it remains visible most of the night. It is the "Winter Red Supergiant," the counterpart to Antares, the bright star in Scorpius that serves as our "Summer Red Supergiant." Although Antares is front and center and the summer is now roaring on all six cylinders, Betelgeuse has emerged into the morning sky and, if the last few thousand of years are any guidance, will take it place into evening sky prominence.
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