Thursday, July 9, 2020

The Dog Star on the Prowl

Southeast 9:00 p.m., January 14th. Submitted

Southeast 9:00 p.m., January 14th. Submitted

by Mike P. Usher

Tonight Sirius has climbed well into the sky; it’s the brightest star in the sky as well as in its constellation Canis Major, the Big Dog. Canis Major is usually associated with Orion as one of his hunting dogs; it appears to be chasing Lepus the hare. There are quite a few other animals nearby tonight; Monoceros the unicorn, Columbia the dove, Cancer the crab and Canis Minor the little dog. Both Cancer and Monoceros are excessively faint constellations, quite difficult to pick out, although Cancer has a fine star cluster for binoculars as a reward for finding it. Praesepe is known as the beehive cluster as the stars in it seem to swarm like bees. Canis Minor consists of just two stars, but one of them is the very bright star Procyon. Columbia is a modern constellation; it’s primary purpose is to fill up a gap in the sky between other constellations.

It’s probably about time we talked about stellar naming conventions. About 250 stars have proper names; most of them are extremely obscure and are virtually never used except in science fiction. Only about two dozen are in common use. The names are mostly of Arabic origin like Betelgeuse, some Greek names like Sirius, together with a handful of Latin derived names like Bellatrix. Constellation names are all Latin. Traditional names are used extensively in the accompanying star charts partly because the software uses them and partly for the historical flavor. It’s important to realize, except for the brightest two dozen or so, Astronomers never use or even learn the names. If you spoke about Bellatrix for example, a blank look would be the only response. Instead Astronomers use catalog designations. There are many catalogs in use; the one most commonly encountered for the brighter stars is the 400 hundred year old Bayer catalog. In this catalog stars are referred to by Greek alphabet letters together with the constellation name in Latin genitive case. Bellatrix would be properly referred to in scientific works as “Gamma Orionis”. Newer catalogs read like serial numbers; in one common catalog Bellatrix is “HIP 25336”.

A number of companies will tell you that for a fee they will assign to a star a name of a relative. This is misleading at best and fraudulent at worst. No private company can assign an official name to an astronomical body. By international treaty only the International Astronomical Union has the right to assign names to astronomical bodies. The IAU does not assign names to stars and has no plans to do so. They don’t even maintain an official pronunciation guide for the traditional star names we do have. Just how does one pronounce Zubeneschamali anyway? (Maybe calling it “Beta Librae” isn’t such a bad idea.)

Mr. Usher is President of the Everglades Astronomical Society which meets every second Tuesday at 7:00PM at the Norris Center, Cambier Park, Naples.

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