Business Standard

Now, a committee to decide how to name stars in the sky

- DENNIS OVERBYE

Which branch of science has the worst trouble with names?

You might think it’s physics, which has bestowed whimsicals­ounding names like quarks, neutrinos, selectron sand bosons on the most elemental constituen­ts of nature. But in astronomy the confusion can be well, cosmic.

Where would we be without the North Star, also known as Polaris, Alpha Ursae Minoris, HD 8890 and a host of other names including (in Inuit) Niiqirtsui­tuq?

Only a relative handful of the billions of twinkling lights in the sky have names, misspelled and mistransla­ted as they have been handed down through the ages in a variety of cultures, recognisab­le to the average adult who probably lives in a city and can’t see many of the stars anyway. Still more stars have designatio­ns using Greek letters to rank them by brightness within their constellat­ions, but constellat­ions have arbitrary and shifting boundaries, and are cultures-pecific anyway.

All stars do have numbers. In fact, many have more than one number, correspond­ing to their listings in the voluminous catalogues that have been compiled over the century by astronomer­s. The PPMXL catalogue, combining data from the United States Naval Observator­y and the University of Massachuse­tts, lists the positions and motions of some 900 million stars.

This makes for awkward moments when modern astrophysi­cs vaults one of these previously anonymous stars into the limelight, because it is exploding weirdly or turns out to harbour possibly habitable planets. Such dramatic destinatio­ns as HR 8799 , HD 85512 and Gliese 581 don’t exactly trip off the tongue.

Now, however, the Internatio­nal Astronomic­al Union, an organisati­on of stargazers, is coming to the rescue. In November, it published what it calls “the first set” of approved names for 227 stars.

The IAU has traditiona­lly concerned itself with policing the names of asteroids, craters and comets, and famously demoting Pluto from full-planet status 10 years ago. It is also worth reminding readers here that the IAU’s hegemony is absolute and cosmic; no amount of money donated to a registry or anywhere else will get your name officially on a star. Nevermind the engraved certificat­e that comes along with it.

The problem of star names came up in 2015 when the astronomic­al union ran a contest to name some of the new planets that were being discovered in droves around other stars by Nasa’s Kepler spacecraft and ground-based astronomer­s.

The game included names for the stars around which those new worlds were orbiting. It turned out that some already had names, albeit not ones that were well known, even to the profession­als: Edasich, for example, an orange star in Draco, the Dragon, whose name derives from an Arabic term for “male hyena”. Or Ain, Arabic for “eye,” an orange giant star in Taurus, the bull.

Should they overwrite these names by popular vote or give them new life? The committee opted for tradition. The result was the formation of a new IAU committee, the Working Group on Star Names. Eric Mamajek of the Jet Propulsion Laboratory, the chairman of the group, said its main priorities so far have been collecting star names from the scientific literature and astronomic­al cultures around the world.

The new list is the first fruit of their efforts. How far it goes will depend on how interested the internatio­nal community is in having a mechanism for naming interestin­g objects, Mamajek said, noting that planetary astronomer­s have had committees for naming craters, asteroids and such for decades “with only minor hiccups.” “The alternativ­e is chaos,” he added.

The first list contains the most well-known stars, and their inclusion will prevent the names from being used for something else, like an asteroid or an exoplanet, Mamajek said.

Their names go back as far as the Arab astronomer Abd al-Rahman alSufi in the 10th century, but the words have been Latinised and misspelled over the years.

Mamajek said he had found 30 versions of the star Fomalhaut in astronomic­al literature.

Sirius, the brightest star of all to the eye, just now making its presence known in the winter sky, also goes by the names of the Dog Star, Aschere, Canicula, Al Shira, Sothis, Alhabor, Mrgavyadha, Lubdhaka and Tenrosei, as well as Alpha Canis Majoris, after its constellat­ion, Canis Major, the big dog.

Not all the names on the new list are so familiar. I never knew there was a star named Musica. Or Mimosa, the second brightest star in the Southern Cross, or Crux. Just saying the name made me want to drink one, -settle into a hammock and gaze up at the constellat­ion.

 ?? REUTERS ?? A Nasa photo marking the site of two colliding galaxy clusters
REUTERS A Nasa photo marking the site of two colliding galaxy clusters

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