The Milky Way is getting bigger: Scientists say our galaxy is growing by 500 meters per second

4/4/2018 11:19:00 AM
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Tehran(KNA) : Scientists have determined that the Milky Way is expanding as new stars form.

The Milky Way is growing and scientists now say it will expand into its neighbor Andromeda.

But, thankfully, the cosmic collision will not happen for about another four billion years.

The Milky Way, a barred spiral galaxy, is already huge with a diameter of about 100,000 light years.

It is home to several hundred billion stars, including the sun which occupies an insignificant spot within one of its minor spiral arms.

At the outer edge of the main body of the galaxy, the galactic disc, new stars are still being created out of gas and dust.

Computer simulations suggest that the new stars will slowly increase the size of the galaxy.

To check if this was right, scientists looked at other galaxies similar to the Milky Way using a number of ground-based and space telescopes.

They calculated that the Milky Way, and other galaxies like it, are growing at around 500 meters per second.

Lead researcher Cristina Martinez-Lombilla said: 'The Milky Way is pretty big already. But our work shows that at least the visible part of it is slowly increasing in size, as stars form on the galactic outskirts.

'It won't be quick, but if you could travel forward in time and look at the galaxy in three billion years' time it would be about five percent bigger than today.'

In about four billion years the Milky Way is predicted to collide and merge with its neighbor, the Andromeda galaxy, Martinez-Lombilla said.

Currently a safe two-and-a-half million light years away, the Andromeda galaxy is even larger than the Milky Way.

Also a spiral galaxy, it is 110,000 light years across and contains an estimated one trillion stars.

A statement from the Royal Astronomical Society explained the significance of the new findings.

It said: 'The nature of this interaction determines the shape of a galaxy, which may be spiral, elliptical or irregular.

'As a barred spiral, the Milky Way consists of a disc in which stars, dust and gas lie mostly in a flat plane, with arms stretching out from a central bar.'

The statement said studying the Milky Way is difficult for scientists given the restraints that come with living on earth.

'One problem in establishing the shape of the Milky Way is that we live inside it, so astronomers look at similar galaxies elsewhere as analogues for our own,' it said.

Separate research has proven that the heart of the Milky Way that exists today developed over a period of four billion years.

The Royal Astronomical Society said that this goes against previous research on the topic.

A statement from the society said: 'The Milky Way contains about a quarter of the total mass of stars. Previous studies have shown that the bulge hosts two components: a population of metal-poor stars that have a spherical distribution and a population of metal-rich stars that form an elongated bar with a "waist" like an x or a bi-lobed peanut.

'However, analyses of the ages of the stars to date have produced conflicting results.

'Now, an international team have analyzed the color, brightness and spectral information of chemistry of individual starts to produce the age-map of the Milky Way.'

This age-map is the first of its kind that outlines the formation of the galaxy.

The team used simulated data and analyzed millions of stars for the project.

Maria Rejkuba, who is presenting the new research, said: 'We analyzed the color and brightness of stars to find those that have just reached the point of exhausting their hydrogen fuel-burning core, which is a sensitive age indicator.'

She explained that the team's findings were inconsistent with the theory that the Milky Way's bulge is 'purely old'.


Source: Daily Mail

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