Bronco-busting With Taurus The Bull

The first time my mom told me she loved watching bull riding I was truly surprised. Lorraine’s this petite woman who attends the symphony and breaks out the ornate china coffee cups after holiday dinners. "Really?" I asked. She and my dad both enjoy sitting together in the TV room to catch bucking bronco action on cable every week.

Taurus is the celestial bull and one of the constellations of the zodiac. It brightest star, Aldebaran (AL-DEB-are-un), along with the Hyades star cluster, forms the bull’s face. El Nath is the second brightest star and marks the tip of one of the horns. All charts created with Stellarium.

I like a good bull too but mine’s a more peaceful sort that snorts above the constellation Orion on cold fall nights. Orion the Hunter grabs so much attention, you have to take your eyes off of him to appreciate so many of the other characters in the neighborhood. Taurus is notable because its outline actually resembles a bull. Bright Aldebaran is one of the eyes, the V-shaped Hyades star cluster the face and two stars to the east punctuate the tips of his horns.

The bull was one of the original 48 constellations that were cataloged by the the Greeks in the B.C. era but traces its lineage much further back in time to the Egyptians and Sumerians. Seven thousand years ago the sun was in Taurus near the Seven Sisters star cluster on the first day of spring or vernal equinox. Given such auspicious timing, the bull was associated  with rebirth and renewal in the early days of civilization. The Greek myth connects these stars with Zeus, who disguised himself as a white bull with golden horns to attract the attention of the fair Phoenician princess Europa. Once she climbed up on his shoulders, he abducted her and trotted off to make her his mistress. This was neither the first nor the last of Zeus’ affairs. If Greek king of the gods were around today, he’d make for a great character in a soap opera.

You can find Taurus two easy ways, one of which is illustrated above. Face to the east around 8 o’clock and look halfway up in the sky to spot the Seven Sisters cluster. It’s that fuzzy, compact clutch of stars shaped like a dipper. Now reach your arm out to the sky and look about one fist directly below the cluster. The bright ruddy star there is Aldebaran and the V-shaped sprinkling of stars, the Hyades. The "horn stars" are one fist to the left or east of Aldebaran. A line drawn through Orion’s Belt upward will also take you straight to Aldebaran.

Earlier this week I spent time roaming Taurus with telescope and binoculars. Two familiar star clusters in the constellation — the Pleiades or Seven Sisters and the Hyades — are among the brightest and finest in the sky. Both are easily visible with the naked eye and multiple in beauty and brightness when seen through binoculars. The Pleiades is some 400 light years away and more compact than the Hyades, which are about 150 light years from Earth. Aldebaran is just 65 light years away and completely unrelated to the Hyades. Picture it in your mind’s eye for what it really is — a foreground star. You’ll have to admit though that it nicely completes the outline of the V.

This closeup map features the two star clusters shown in the wide map above. Each blue circle of sky is what you see in a typical pair of binoculars. NGC1647 is just to the left or east of Aldebaran and in the same field of view. You can use the horn star El Nath to guide you to NGC 1746.

Skywatchers wishing to ride the bull into deeper territory will want to take out their binoculars to find two other star clusters: NGC 1647 and NGC 1746. NGC stands for New General Catalog, a compendium of over 7800 galaxies, star clusters and nebulas observed or discovered by the famous deep sky hunting Herschel family in the late 18th and early 19th centuries. These two NGCs in Taurus are both 6th magnitude or just at the limit of naked eye visibility under pristine skies. I have no trouble seeing either in my 8×40 binoculars from home here in Duluth. NGC 1647 is just a little larger than the full moon and reveals a half dozen dim stars shimmering against a hazy background glow of fainter members. NGC 1746, while listed as nearly the same size as 1647, looks larger to me with about a dozen stars seen against the glow of more. These clusters aren’t terribly bright so be sure you allow your eyes to adapt to the darkness before seeking them out.

Here’s a photo of our two "deeper" Taurus star clusters. Both are much further from us than the Hyades and Pleiades. NGC 1647 is about 1700 light years away while its neighbor’s distance is between 1500 and 2100 light years. Details: 70mm lens at f/2.8. 15-second time exposure at ISO 3200. Photo: Bob King

Since both clusters are gangly and rather large, a low power telescope will show them well. Don’t put in too much magnification though or you’ll spread the stars out so far they’ll loose they’re clustery look. NGC 1746 is a bit enigmatic since it may actually consists of two to three overlapping clusters with the numbers NGC 1750 and 1758. Either way, Taurus the Bull belongs on your list of nightly adventures this season.

Tomorrow we’ll visit a very little known spot in the constellation that has galactic implications. See you then!

Planet highlights this week include the moon passing near Saturn on the 10th and the return of Mercury to the evening sky. Illustration: Bob King