Washington: Astronomers have discovered what they believe is the brightest and youngest ever spinning star, suggesting that the extremely luminous versions of these super-dense objects may be far more common than thought.

The fast-spinning star, or a millisecond pulsar called J1823-3021A, is located inside a packed conglomeration of stars called a globular cluster about 27,000 light-years from Earth in the constellation Sagitarrius.

The pulsar emits incredibly intense high-energy gamma rays, which the researchers detected and studied using NASA's Fermi Gamma-Ray Space Telescope.

Their analysis suggested that the pulsar is 25 million years old -- just a baby, as millisecond pulsars tend to be a billion years old or so, reports said.

The pulsar's extreme brightness challenge the existing ideas about how super-bright millisecond pulsars form and how widespread they may be, the researchers said.

"These anomalously energetic millisecond pulsars must be forming at a rate similar to the previously known, more normal millisecond pulsars at least in globular clusters, but possibly in the whole universe as well," lead researcher Paulo Freire, of the Max Planck Institute for Radio Astronomy in
Germany, said.

"In a sense, this pulsar would be the proverbial tip of a hidden new iceberg."

Pulsars form when giant stars die in supernova explosions and their remnants collapse into compact objects made only of the particles called neutrons.

When a mass as great as of Sun's is packed into a space, the conserved angular momentum causes the resulting neutron star to spin very rapidly and to emit a ray of high-energy light that sweeps around like a lighthouse beam.

This light appears to pulse because astronomers see the beam only when it's pointed at Earth. "Normal" pulsars rotate at a rate between seven and 3,750 revolutions per minute, but millisecond pulsars, according to researchers, can spin much faster up to 43,000 rotations per minute.

These hyper-spinners are thought to be revved up by accretion of matter from a companion star. Indeed, roughly 80 per cent of millisecond pulsars discovered to date is found in binary systems, researchers said.

The new study, published in the journal Science, could shed some more light on these exotic objects, scientists said.

In a separate study, astronomers announced the discovery of nine previously unknown gamma-ray pulsars, also using the Fermi space telescope.

Those pulsars had gone unnoticed because they do not shine brightly despite their high energy level, the scientists with the Max Planck Institute for Gravitational Physics said.

(Agencies)