Looking up at the constellation Orion

Tonight – or any January evening – look for the constellation Orion the Hunter. It’s probably the easiest to pick out of all the constellations in the winter sky. It’s identifiable by Orion’s Belt, three medium-bright stars in a short, straight row at the mid-section of the Hunter. See these stars? They are easy to spot on the sky’s dome. As seen from mid-northern latitudes, you’ll find Orion in the southeast at early evening and shining high in the south by late evening (around 10 to 11 p.m. local time). If you live at temperate latitudes to the south of the equator, you’ll see Orion high in your northern sky at this hour. Pick out Orion’s Belt and the nearby bright stars in that part of the sky, and you’ve probably found Orion.

orion-sky

Stars in distinct constellations like Orion look connected, perhaps even gravitationally bound, but usually they aren’t. Certainly Orion’s stars aren’t bound to each other by anything but their general location near one another along a single line of sight from Earth. The stars of Orion just happen to make an easy visual pattern on our sky’s dome.

Meanwhile, the stars in Orion and most other constellations are located at vastly different distances from each other. For example, notice the two brightest stars in Orion—Betelgeuse and Rigel.  Betelgeuse is estimated to be located 522 light-years away, while Rigel’s distance is 773 light-years.

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