14 | NewScientist | 8 September 2012

AN OPTICAL telescope and a stopwatch might be all you need to track ripples in space-time.

According to Einstein’s theory of general relativity, accelerating objects, like stars orbiting one another, should shed energy as gravitational waves. These space-time ripples cause the two stars to orbit ever closer, an effect that is easier to detect than the waves themselves. It has already been

measured in pulsars, a type of spinning star, although this requires a radio telescope to track the pulses they emit.

Now J. J. Hermes of the University of Texas, Austin, and colleagues have seen the same effect with an optical telescope. They observed a pair of white-dwarf stars called J0651, which orbit each other every 12.75 minutes. The researchers found that the stars

Galactic evolution tastes of hot DOG

THIS frankfurter won’t fit on a bun. Newly discovered hot dust-obscured galaxies, or hot DOGs, could help explain how a galaxy’s evolution is influenced by the black hole at its core.

Though 1000 times brighter than the Milky Way, these dusty galaxies went unseen until a team led by Jingwen Wu of NASA’s Jet Propulsion Laboratory in Pasadena, California, observed their infrared radiation.

The team used this to calculate the mass of the hot DOGs’ central black holes, which are heavier relative to the surrounding stars than black holes in an ordinary galaxy (Astrophysical Journal, doi.org/h8g). The team says all galaxies may go through a hot DOG stage as they evolve. Once the black hole has eaten or ejected all the nearby dust and stopped growing, ongoing star formation eventually turns the hot DOG into a normal galaxy.

Was Scott’s fate sealed by the actions of his own team?

THE death of Robert Falcon Scott as he returned from the South Pole may partly have been the result of the actions of his own colleagues, a new book claims.

En route to the South Pole (pictured), Scott’s team laid down depots of food and fuel. It is well known that they found supplies low at some of these on the way back. Now Chris Turney of the University of New South Wales in Sydney claims there was a shortfall on the return leg that has only recently come to light. He has discovered notes from a meeting in 1914 between the widow of Edward Wilson, who died with Scott, and the president of the

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IN BRIEF

Dead star duo in low-tech Einstein test orbited each other a quarter of a millisecond faster than a year ago, and attribute this to gravitational waves (arxiv.org/abs/1208.5051). That may not sound like much, but it amounts to a shift of 6 seconds in the timing of eclipses of one star by the other, compared with if the system were not emitting gravitational waves.

Detecting Einstein’s waves directly requires a more complicated set-up like the eLISA experiment, due to go live in 2025.

Royal Geographical Society. At the meeting, Oriana Wilson revealed that her husband’s diary mentions an “inexplicable” food shortage on the return journey. Turney believes this refers to a depot reached on 24 February 1912, when the team were on the home stretch, and starving.

Turney points the finger at Teddy Evans, Scott’s second-in-command, whom Scott told to turn back 200 kilometres from the pole. Evans then got scurvy and had to be pulled on a sledge, which may have caused his group to take more than their fair share of food.

Scott died just 18 kilometres from the final food depot. Had he reached it, he probably would have survived.

Turney’s claims appear in 1912: The year the world discovered Antarctica, published this week.

A SCIENCE-FICTION scene could be playing out for real about 4900 light years from Earth, where astronomers have spotted the first known pair of planets jointly orbiting a binary star system (Science, doi.org/h8h).

One of the planets is in the habitable zone, the region around the suns where liquid water – and maybe life – can exist.

Dubbed Kepler-47c, this planet is almost certainly a gas giant. But if it has any rocky moons, they could be ripe for life, like Endor in Star Wars or Avatar’s Pandora.

Because binary stars are very common, the discovery doubles the likely population of habitable worlds, says team member Dan Fabrycky of the University of California, Santa Cruz.

Twin stars may host Endor-like moons

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