Hunting Season

Orion is full of wonders.

By Bob Berman|Tuesday, February 01, 1994
RELATED TAGS: STARS

Orion’s brilliant belt of stars is often the first celestial pattern a child will notice. It was for me. And what better place to start strolling the boulevards of the universe? The constellation Orion is more than merely lovely and obvious; it’s like a navigational buoy floating in the middle of the sky, pointing the way to the nearest spiral arm of our galaxy.

Can the sky have a middle? Yes. Orion’s belt, that most famous article of cosmic clothing, sits smack on the celestial equator, meaning it lies directly over Earth’s equator. Only stars in that location are seen by everyone, everywhere. A star near one of the poles--the North Star, say--is forever cloaked from people of the opposite hemisphere, obstructed by Earth itself. From the vantage of most of the United States, about a fourth of the cosmos never rises above the horizon. Major luminaries concealed from view include the nearest star (Proxima Centauri), the night’s second brightest (Canopus), and the Southern Cross. But unlike such parochial stars, equatorial constellations span the hemispheres. Orion’s belt, straddling the equator like some celestial bridge, is visible the world over.

Not all cultures, by the way, have seen a belt, much less a hunter, in the array of stars we call Orion. Some ancient astronomers visualized the trio of belt stars as the waistline of a sheep! But whether seen to limn an ovine or human figure, the constellation’s stars are not scattered randomly. Most share the same awesome distance of 900 to 2,000 light-years, forming a lavish association of blue suns of arc-lamp intensity. These infants, merely one-thousandth the age of Earth, were born together from an immense cloud of gas that still dreamily envelops the constellation.

If you live in a light-polluted region, binoculars pointed at Orion’s belt show it immersed in a multitude of stars like a swarm of fireflies. In rural areas you can see this faint cluster with the naked eye. Your sky passes the purity test if many more than just the three belt stars are visible. Regardless of how many you see, Orion’s stars carry your gaze all the way to the Orion Spur, a branch of the Perseus arm of the galaxy, the next spiral arm outward from our own.

While the binoculars are handy, swing them below the leftmost belt star to the nearest little fuzzy patch: the Orion nebula. Use whatever you’ve got--telescope or binoculars--and watch the nebula metamorphose into a grand, wing-shaped interstellar cloud. Photography brings out the crimson, emerald, and blue of its radiant dust, encircling the fires of newborn suns. This stellar nursery is so large that our fastest rockets would need more than 500,000 years to cross it. Stars are being born there before our eyes even now. The entire womb glows like neon, an ultraviolet excitation generated by the quartet of blue suns blazing in the center--the famous Trapezium, gloriously seen through any telescope.

Just above and below the belt stand pumpkin-colored Betelgeuse and blue-white Rigel. More than just Orion’s brightest star, Rigel is among the most luminous objects in the galaxy, shining with the light of 55,000 suns. If it were as nearby as Proxima Centauri, we could read by its light, and the night sky would be deep blue instead of black. At 900 light-years away, it is the most distant of the night’s brightest stars. And it is only one of the gems in Orion that will adorn February’s sky every winter of our lives.

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