Alnitak, Alnilam, Mintaka

Last week in this space, on the topic of the world’s 20 most widely-spoken languages, I mentioned a few words in English that came from Arabic. It has since occurred to me that more examples are hanging over Saipan’s head. That’s because many stars carry Arabic names, including, notably, the three bright stars that comprise the neat line of Orion’s belt.

I suspect that Orion, named for a hunter from Greek lore, is humanity’s most widely-recognized constellation. Orion is easily recognized via the three stars of the belt; via the bright red star called Betelgeuse that signifies Orion’s right shoulder; and via the bright white star called Rigel that signifies Orion’s left foot. On that note, this whole “left” and “right” business assumes that Orion is facing us, and of course he is. After all, he’s our pal, and a very good pal at that.

Although the prime viewing season for Orion is drawing to its annual close right now, it’s still convenient to view Orion from Saipan. At 8pm these days, Orion is high overhead in Saipan’s south-southeastern sky.

If you take a look at about that time, you’ll notice that Orion is sort of lying down, and his belt is, more or less, running vertically. Going from the lowest of the belt’s stars and proceeding upwards, the stars are named Alnitak, Alnilam, and Mintaka. These Arab names are said to mean, respectively, “girdle” or “belt;” “string of pearls;” and “belt.” Their distances from Earth are, again respectively, 817 light-years; 1,977 light-years; and 917 light-years.

They are some of the most distant of the prominent stars.

Yet, despite the great distances, they’re all very bright. All three, in fact, are monster stars, “supergiant” stars that shine tens of thousands times brighter than the sun does. If you put a hairy eyeball on them you’ll notice they’re all blue, which, in the stellar realm of visible colors, means they’re the hottest burners.

Alnitak and Mintaka have surface temperatures of about 60,000F, while Alnilam is cooking at 50,000F.

Blue supergiant stars are extremely rare. However, they’re so bright that they are disproportionately visible among their far more numerous, but far duller, brethren.

To put this in context, our sun, a very mild, whitish-yellow star, has a surface temperature of about 10,000F.

With that in mind for scale, we can now put our focus back on Orion and contemplate Betelgeuse, which, as a red star, is in the coolest visual category of stars, burning at about 6000F. And, yes, Betelgeuse is also an Arabic name, said to mean the hand of the giant (the giant being Orion) or the armpit of the giant. Betelgeuse is also a monster star, a supergiant that’s roughly 900 time to 1,000 times the diameter of our sun.

Since Orion is a prominent feature of the sky, it is, logically enough, used as a guidepost to other celestial sights. For example, if you extend the line of Orion’s belt down toward the horizon (again, using our 8pm benchmark for Saipan) you’ll come to Sirius, the brightest star in the entire night sky. Sirius itself isn’t all that remarkable. It’s bright because it’s very close at 8.6 light-years.

Saipan actually gets a bonus here, which our friends to the north in Beijing, Tokyo, and Seoul have probably never seen from home: Canopus, the second-brightest star in the night sky, which is roughly between Sirius and due south. Canopus is 309 light-years distant.

In summary, then, Saipan offers an array of noteworthy stars in Orion’s sector of the sky: Betelgeuse, the red supergiant; Alnitak, Alnilam, and Mintaka, the blue supergiants of Orion’s belt; Rigel, which is also a blue supergiant; Sirius, the brightest star in the night sky; and Canopus, the second-brightest star in the night sky.

There’s far more to Orion’s neighborhood, but I’m going to change course so I can address readers who have some engagement in navigation. Saipan, after all, has hosted its share of tropical adventurers. One useful fact about Orion is that Mintaka pretty much sits smack-dab on top of the celestial horizon. Another useful fact is that Orion’s sword, which, of course, hangs down from the belt, hangs toward celestial due south. With these two facts in mind, Orion can really help you get your bearings if you’re in the middle of nowhere.

Stepping back to the most general of perspectives, the arm of the galaxy on which Earth’s solar system resides is called the Orion Spur. It’s also called the Orion Arm. Either way, Orion is a very big deal and a very big benchmark.

So enjoy the view!

Ed Stephens Jr. | Special to the Saipan Tribune
Visit Ed Stephens Jr. at EdStephensJr.com. His column runs every Friday.
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