Every once in awhile a scientist’s wise crack sticks as a new discovery’s name. In astronomy that hasn’t happened since, oh, the Big Bang. (The Face on Mars doesn’t count because the loons who saluted that one were serious.) The only problem with this latest one is that one must, to almost everybody, explain the joke’s point (literally). Plus,  as the news broke late Thursday, The Tracker is late to get (to) it myself.

The inside-the-church hilarity revolves around a supernova detected seven years ago, in a galaxy about 160 million miles away. The spectrum was recorded by an automatic telescope and virtually filed away. A UC Berkeley group finally took a much closer look. It concluded it was not the Type II supernova suspected (that’d be when a massive star’s core collapses into a black hole and the rest is blown away). Instead, its fast fade, relative dimness, and odd spectrum betrayed it as the explosion of a white dwarf star that, in dangerously tight orbit with another white dwarf, had stolen such a load of helium from its partner’s atmopshere it (or its surface at least) blew up. Such things were  predicted but nobody had seen one.

A Harvard man chuckled that such a thing would be a .Ia supernova. Astronomers fell down in stitches, “a point one-a !! whooaa ha ha..”

See, that’s because the only other supernovae known to involve white dwarfs are called type Ia and this new one released about a tenth the energy … and the joke  just died from exploratory surgery. Details are in AAAS’s ScienceExpress. Two UC campuses and the National Science Foundation put out press releases, so everybody had a crack at sharing the news that the .Ia supernova now has an exemplar.

By any assessment, supernova classification is a clumsy and awkward thing, the result of historic overlays of namings. As one sees below, it befuddled a few reporters.

Stories:

• San Francisco Chronicle – David Perlman : Supernova fits into a new class ; Good for Perlman, he gets on his own the story of the blast’s discovery in 2002 by two amateurs, using robotic telescopes tuned to record new dots on the sky, hours before the pros saw it. He doesn’t bother with the decimal point joke. One little tiny flub – the story has the distance as 135 million ly sted the correct (accdg to the paper which gives it as 50 ± 5 parsecs) 163 million ly or so. Or maybe the astronomers told him something different?
• Nat’l Geographic – Ker Than: New Type of Supernova Discovered ;  He provides the point, doesn’t say it started as a joke. Same reason probably – hardly anybody would get it.
• ABC Science Online (Australia) Stuart Gary ; Mysterious supernova in a class of its own ;  This story has problems. First, it suggests that this new one so muddles supernovae classification that using the regular Type Ia versions as “standard candles” for distance estimation has just become more uncertain. It  is hard to see how this discovery changes that situation. More important he calls the standard-candle ones as belonging to the “Type I” supernovae class. No such single thing – it’s a diverse category. There are Ia ones that involve white dwarfs in the usual way (they explode after absorbing H from a close, more normal star), plus Ib and Ic types involving collapses of giant stars of unusual composition with little or no hydrogen. The nomenclature is a mess all by itself but this story messes it up even further.
• Jerusalem Post – Judy Siegel-Itzkovich: US-Israeli team’s speedily evolving supernova seems to be a new class of exploding star; One of the authors is a Tel Aviv U.  grad. Nice job, although the story’s explanation of white dwarf is a bit off – confusing their interior bulks of carbon and oxygen with a shallow atmosphere that may include helium.
• Space.com – Andrea Thompson : New Type of Supernova Discovered ; She too drops the a off Type Ia, a little thing but, in the supernova world, an error that’d get a grad student in deep trouble during orals.

Grist for the Mill:

UCBerkeley Press Release ;

NSF Press Release ;

UC Santa Barbara Press Release (home of the work that predicted these things).

- Charlie Petit

This entry was posted on Monday, November 9th, 2009 at 12:27 pm and is filed under Science Stories. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.