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Bright star Arcturus is a harbinger of spring

2015-march-12-arcturus-bootes-herdsman-night-sky-chart

Tonight for March 12, 2015

At mid-northern latitudes, the gloriously bright star Arcturus rises into the east-northeastern sky by around 9 p.m. tonight. This yellow-orange beauty – like any brilliant star – sparkles wildly when it hovers near the horizon. Arcturus is the brightest star in the constellation Bootes, which represents a Herdsman – though to our modern eyes, this star formation might look more like a kite or snow cone.

Arcturus will climb highest up for the night around 4 a.m. local time and will beam high in the western sky at dawn. You can verify that you’re looking at Arcturus by “arcing to Arcturus” via the Big Dipper handle, as depicted in the sky chart below.

2015-march-12-text-arcturus-big-dipper-night-sky-chart

Arcturus is the 4th brightest star in the night sky, after Sirius, Canopus, and Alpha Centauri. Sirius shines brightly on winter evenings. The famous southern star Canopus does, too, as seen from latitudes like those in the southern U.S. Alpha Centauri is too far south to be seen from the continental U.S. So Arcturus is worth getting to know. It is not only bright but also – due to its northerly location on the sky’s dome – visible for much of the year for Northern Hemisphere stargazers.

Arcturus’ appearance in the evening sky is a welcome sign in our northern climes, because it heralds the coming of the spring equinox, or first day of spring. After the equinox this March 20, the daylight hours will begin to surpass the nighttime hours in length.

Arcturus, like any star, rises 4 minutes earlier every day. In a week or so, the earlier-rising Arcturus will first beam at dusk, instead of nightfall or early evening. Around the time that happens, spring will return to our Northern Hemisphere!

Hamal: Ancient equinox star

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