14 | NewScientist | 29 January 2011

WILL the Milky Way slam into its giant neighbour, Andromeda, in a few billion years? A laser-like spot of light in the galaxy hints at an answer.

The speed at which Andromeda is moving towards the Milky Way can be determined from the Doppler shift of the light it emits. But the galaxy is too spread out for its subtle sideways motion in the sky to be detected. If it moves

fast enough in this direction it may miss the Milky Way altogether.

Now Loránt Sjouwerman of the National Radio Astronomy Observatory in Socorro, New Mexico, and colleagues have glimpsed a bright, laser-like spot of microwave radiation, called a maser, in Andromeda that could help determine its sideways motion (Astrophysical Journal Letters, DOI: 10.1088/2041-

Plastic looks good for retina repair

LIGHT-SENSITIVE plastic might be key to repairing damaged retinas.

Creating neuro-prosthetic devices such as retinal implants is tricky because biological tissue doesn’t mix well with electronics – but it might mix with organic semiconductors.

To find out, Fabio Benfenati at the Italian Institute of Technology in Milan, and colleagues, seeded nerve cells onto the surface of a light-sensitive semiconducting polymer, and made it into the electrode of a light-driven electrolytic cell.

The cells grew into networks over the material without affecting its optical properties. When short pulses of light were aimed at specific sections of the polymer, only local neurons fired, suggesting the material has the spatial selectivity needed for artificial retinas, says Benfenati (Nature Communications, DOI: 10.1038/ncomms1164).

Dragonfish nebula conceals giant cluster of baby stars

DRAGONFISH are fearsome deep-sea predators with giant mouths, bulging eyes and a propensity for eating bioluminescent prey. Now it seems they have a celestial counterpart in the Dragonfish nebula. Hidden in its gaping maw may be the Milky Way’s most massive cluster of young stars.

Mubdi Rahman and Norman Murray, both of the University of Toronto in Canada, found the first hint of the cluster in 2010 in the form of a big cloud of ionised gas 30,000 light years from Earth. They picked up the gas by its microwave emissions – suspecting that

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Found! Maser to predict Milky Way’s fate 8205/724/2/L158). Detected with the newly

upgraded Very Large Array of telescopes in New Mexico, the maser appears when interstellar methanol molecules get heated up by nearby stars. Tracking the motion of this bright spot precisely should be easier than the galaxy as a whole, say the team. However, they must first find other masers in Andromeda, to confirm that the maser motion reflects Andromeda’s path overall.

radiation from massive stars nearby had ionised the gas.Now Rahman and his colleagues have identified

a knot of 400 massive stars in the cloud’s heart in images from the infrared 2 Micron All Sky Survey (Astrophysical Journal Letters, in press). The cluster probably contains many more stars too small and dim to see.

The surrounding cloud of ionised gas is producing more microwaves than clouds around other star clusters in our galaxy. That suggests the Dragonfish is the brightest and most massive young cluster discovered so far, with a total mass of around 100,000 times the mass of the sun.

“Until now, we’ve only seen clusters this size outside of our galaxy,” Rahman says. Because it is so much closer, it can be studied in greater detail, he adds.

THE hottest planet ever found is nearly 3200 °C – hotter than some stars.

The discovery of the planet, called WASP-33b, was confirmed in 2010, when it was found to be less than 4.5 times the mass of Jupiter.

Now Alexis Smith of Keele University in Staffordshire, UK, and colleagues have taken its temperature using an infrared camera on the William Herschel Telescope in the Canary Islands (arxiv.org/abs/1101.2432).

Its record-breaking temperature is partly due to its close orbit around its star, which is just 7 per cent of the distance between Mercury and the sun. Not only that, but, at 7160 °C, its scorcher of a star is one of the hottest planet-hosting stars known.

Exoplanet is hotter than some stars