Now you see it, now you don't

Feb 22, 2006

Some stars emit radio waves fairly steadily, while some compact neutron stars flash like beacons in the sky. But others brighten and dim erratically, without any discernible pattern to the outbursts, according to Maura McLaughlin in research published by Nature last week.

The team have discovered a new class of astrophysical objects, which they call rotating radio transients (RRATs). These emit short bursts of radio waves, lasting just 2 to 30 milliseconds, interspersed with 'dark' spells of several minutes to hours. The researchers say that the radio signals from these objects are typically detectable for less than a second in total each day.

The researchers have discovered eleven such objects in a four-year survey conducted to look for transient radio sources of this kind. Although the bright events are so short, they nevertheless show signs of periodicity for ten of the objects, repeating in cycles of 0.4 to 7 seconds. In other words, the objects are rather like lighthouses that are plagued by frequent, random and prolonged power cuts.

What causes these shutdowns? McLaughlin and colleagues aren't sure what RRATs are yet, beyond supposing that they are a kind of rotating neutron star. But they seem to be plentiful: the researchers estimate that there should be many more of them in our Galaxy than there are regularly pulsing neutron stars. It's just that, because they are 'dark' most of the time, they can only be seen by looking hard and long.

Source: Nature

Explore further: Russia launches British comms satellite into space

add to favorites email to friend print save as pdf

Related Stories

Chandra celebrates the International Year of Light

Jan 23, 2015

The year of 2015 has been declared the International Year of Light (IYL) by the United Nations. Organizations, institutions, and individuals involved in the science and applications of light will be joining ...

Snapshot of cosmic burst of radio waves

Jan 19, 2015

A strange phenomenon has been observed by astronomers right as it was happening - a 'fast radio burst'. The eruption is described as an extremely short, sharp flash of radio waves from an unknown source in ...

Recommended for you

Japan launches new spy satellite

12 hours ago

Japan on Sunday successfully launched a back-up spy satellite, its aerospace agency said, after cancelling an earlier lift-off due to bad weather.

NASA launches satellite to measure soil moisture

12 hours ago

NASA on Saturday launched a new Earth-observing satellite that aims to give scientists high-resolution maps showing how much moisture lies in soil in order to improve climate forecasts.

Planck: Gravitational waves remain elusive

Jan 30, 2015

Despite earlier reports of a possible detection, a joint analysis of data from ESA's Planck satellite and the ground-based BICEP2 and Keck Array experiments has found no conclusive evidence of primordial ...

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.