Scientists explain why the Milky Way is so warped

They have found that the Milky Way is not exactly as artist's impressions might have you believe - it's actually twisted and warped, bending at the edges.

But, for the past 50 years there have been indications that the hydrogen clouds in the Milky Way are warped.

"It is notoriously hard to determine distances from the Sun to parts of the Milky Way's outer gas disc without having a clear idea of what that disc actually looks like", lead study author Xiaodian Chen of the Chinese Academy of Sciences in Beijing said in a statement.

An worldwide team of astronomers have discovered that the Milky Way's disc of stars becomes increasingly "warped" and twisted the further away the stars are from the galaxy's center.

Classical Cepheids are young stars that are some four to 20 times as massive as the sun and up to 100,000 times as bright.

Scientists in Australia and China created the galactic map by measuring the distances to more than 1,300 large, pulsating stars that together reveal the true shape of the Milky Way.

Given their mass and brightness, they probably burn through their fuel quickly and die after a few million years - young for the lifetime of a star.

The 1,339 stars are all Cepheid variables, a type of pulsating star whose intrinsic brightness depends on how long it takes to vary from bright to dim and back again. That means that if you know the pulsation period, you can infer the star's actual luminosity, then compare that with the luminosity observed from Earth in order to determine the distance.

"Perhaps more important, in the Milky Way's outer regions, we found that the S-like stellar disk is warped in a progressively twisted spiral pattern", de Grijs said.

The Milky Way isn't alone. According to the researchers, this warped shape could be a result of the huge amount of spinning force produced by the galaxy's massive inner disk.

A new study by the National Astronomical Observatories of Chinese Academy of Sciences (NAOC) might explain the Milky Way's spiral appearance - it's warped.

Researchers from Macquarie University, Australia, and the Chinese Academy of Sciences made their findings after creating a new 3-D map of the Milky Way, which allowed them to better estimate its shape. "This offers new insights into the formation of our home galaxy", Richard de Grijs, senior study co-author and professor at Macquarie University's Department of Physics and Astronomy, said in a statement.

A newly discovered star is thought to be one of the oldest in the Milky Way. In the far outer disc hydrogen atoms making up most of the galaxy are no longer confined to a thin plane.

Spiral galaxies usually appear very flat and easy to see through a telescope, said the researchers behind the new map, published Monday in the journal Nature Astronomy.

IAC director Rafael Rebolo said: 'Detecting lithium gives us crucial information related to Big Bang nucleosynthesis.