Changing designations

Our astronomer wonders about Thor’s Helmet, the Heart and Soul, and other things.

This month’s lunar eclipse has been billed as a Super Wolf Blood Moon, the adjectives appearing in various order.  Our astronomer reminds us that attaching a name to the Full Moon of each month is a very recent idea in our culture.  It may have been common among, for example, the indigenous Americans, but it’s rare to find a reference to it in popular writing before the late twentieth century.  It reminds him of an even more recent attaching of names to things in astronomy.

Originally stars had names.  Not all, but the brightest or most important ones had them, and names still exist for some hundreds (though only a few are now routinely used).  But when the skies began to be mapped systematically there just weren’t enough to go around, and some form of numbering had to be employed.  Certainly by the late nineteenth century, with tens to hundreds of thousands of stars in a catalog, names would have been impossible.

Similarly, if you take a telescope out under a reasonably dark night sky, you can find dozens of faint fuzzy things among the stars.  In fact with one of moderate size (as amateur telescopes go nowadays) at a good site you may locate hundreds.  The first catalog of such objects, compiled by Charles Messier in the eighteenth century, numbers them, and they can be located in databases under such designations as M78.  The systematic labors of Sir William Herschel, using a larger telescope a few decades later, were eventually subsumed into the New General Catalog of non-stellar objects, to which was added the Index Catalog.  NGC numbers run up to 7840; IC, to 5386.  Obviously generating that many names is out of the question.

Some of them did have names, and still do.  For example, the Ring Nebula, the Sombrero and the Black-Eye Nebula showed distinctive shapes and attracted auxiliary names (in addition to M57/NGC6720, M104/NGC4594 and M64/NGC4826).  Most, however, made do with their numbers.  And to astronomers used to working with them the numbers acquired a certain character; mentioning “M77” would immediately conjure up a mental picture of a certain galaxy together with some associated data.

But in the amateur astronomy literature a few years ago our astronomer noticed many more things bearing names.  NGC objects had become “The Heart and Soul Nebula,” “Thor’s Helmet” and the like.  This is peculiar: astronomy had always gone the other way.  Why?

In part, no doubt because the advent of electronic cameras had amazingly increased the depth, detail and beauty of pictures of nebulae.  What had been merely a smudge on the film became a colorful swirl of gas or stars, able to suggest many possible images.  And these were reaching many more people.

The latter, we think, is the main point.  People were seeing and reacting to astronomical pictures who, in the old days of film and books, would never have bothered.  This includes a significant fraction of the active amateur astronomers of today.  And this wider population is less used to working entirely with numbers, more inclined to use names.

More people exposed to, and interested in, science is to be welcomed.  But our astronomer makes no promises about learning all the new names himself.