Milky Way in mid-life crisis

May 25, 2011
Barred Spiral Milky Way. Illustration Credit: R. Hurt (SSC), JPL-Caltech, NASA

(PhysOrg.com) -- The Milky Way is suffering from a mid-life crisis with most of its star formation behind it, new research from Swinburne University of Technology has shown.

Galaxies typically fall into one of two categories – energetic blue that form new stars at an impressive rate, or lethargic red galaxies which are slowly dying.

In a paper accepted for publication in the Astrophysical Journal, Mr Simon Mutch, Dr Darren Croton and Dr Gregory Poole, have shown that our own galaxy is neither of these. Rather it is a rare ‘green valley’ galaxy that is half way between a youthful blue galaxy and a geriatric red one.

This is the first time that astronomers have compared both the colour and the star formation rate of the Milky Way to that of other galaxies in the Universe.

“Determining the state of our own galaxy while we’re stuck inside it is very difficult to do,” Dr Croton said. “The phrase ‘it’s hard to see the forest for the trees’ really rings true here.”

To overcome this, the researchers have taken the best available measurements of the Milky Way from the past 20 years and compiled them into a big picture view of the galaxy's current state.

“The properties we've looked at all point to the Milky Way having global colours that we'd classify as green – they’re midway along an evolutionary track between ‘blue and star forming’ and ‘red and dead’,” Dr Croton said.

According to Mr Mutch, this means that the production of stars in the Milky Way will slow down to a mere trickle over the next few billion years.

“Star formation in our galaxy will continue to decrease,” he said. “But those concerned about the Milky Way’s decline needn’t worry just yet – retirement is still a long way off.”

And according to Dr Poole, even in its twilight years our home galaxy will still have some life left in it.

“In about five billion years, the Milky Way is expected to merge with neighbouring spiral galaxy Andromeda,” he said. “This will liven things up a lot, withy any residual hydrogen gas in both providing a new, but short-lived, burst of .”

‘The Mid-Life Crisis of the Milky Way and M31’ can be downloaded from: arxiv.org/abs/1105.2564v1

Explore further: Young binary star system may form planets with weird and wild orbits

Provided by Swinburne University of Technology

5 /5 (3 votes)

Related Stories

Giant galaxies akin to snowflakes in space

Feb 21, 2011

(PhysOrg.com) -- Giant galaxies that contain billions of stars are born in much the same way as delicate snowflakes, new research from Swinburne University of Technology has shown.

Spiral galaxies may be dying because of bars

Nov 10, 2010

With the help of the army of volunteers working on the Galaxy Zoo 2 'citizen science' project an international team of scientists led by a Portsmouth astrophysicist may have discovered what is killing spiral ...

VLT finds a brilliant but solitary superstar

May 25, 2011

(PhysOrg.com) -- An extraordinarily bright isolated star has been found in a nearby galaxy -- the star is three million times brighter than the Sun. All previous similar "superstars" were found in star clusters, ...

Hiding Out Behind the Milky Way

Apr 07, 2010

(PhysOrg.com) -- A leggy cosmic creature comes out of hiding in this new infrared view from NASA's Wide-field Infrared Survey Explorer, or WISE.

Australian students capture dancing galaxies

Apr 06, 2011

For the second consecutive year, high school students from across Australia joined in a competition to obtain scientifically useful (and aesthetically pleasing) images using the Gemini Observatory. The spectacular ...

Alien invaders pack the Milky Way

Feb 23, 2010

(PhysOrg.com) -- Around a quarter of the globular star clusters in our Milky Way are invaders from other galaxies, new research from Swinburne University of Technology (Australia) shows.

Recommended for you

Image: Hubble serves a slice of stars

4 hours ago

The thin, glowing streak slicing across this image cuts a lonely figure, with only a few foreground stars and galaxies in the distant background for company.

Evidence of a local hot bubble carved by a supernova

Jul 30, 2014

I spent this past weekend backpacking in Rocky Mountain National Park, where although the snow-swept peaks and the dangerously close wildlife were staggering, the night sky stood in triumph. Without a fire, ...

Astronomers measure weight of galaxies, expansion of universe

Jul 30, 2014

Astronomers at the University of British Columbia have collaborated with international researchers to calculate the precise mass of the Milky Way and Andromeda galaxies, dispelling the notion that the two galaxies have similar ...

Mysterious molecules in space

Jul 29, 2014

Over the vast, empty reaches of interstellar space, countless small molecules tumble quietly though the cold vacuum. Forged in the fusion furnaces of ancient stars and ejected into space when those stars ...

User comments : 6

Adjust slider to filter visible comments by rank

Display comments: newest first

kevinrtrs
1 / 5 (14) May 25, 2011
I'm slightly puzzled by the confident statement that "that the production of stars in the Milky Way would slow down over the next few ....". Have they actually observed any single star form from scratch and announce it's new-born state in a brilliant display of light?
We know that there's been an observed contradiction to the theory already with some seemingly old, red and dead stars springing back into life with not much prompting - thereby throwing a spanner in the works of the accepted theory. But of course, true to evolutionary form, that contradiction is ignored in statements to the general public whilst the theory is blithely put forward as being infallible. A modicum of humility and honesty would be so much better to accept.

Donutz
4.5 / 5 (8) May 25, 2011
Yes, and it's a good thing we have all those creotard scientists pointing out inconsistencies in the theories or it would go unnoticed. Oh, wait. There are no creotard scientists. It's secular scientitsts discussing problems with theories. Something called "intellectual honesty". But you wouldnt' understand that, kev.

You're right about needing some humility and honesty, though. You first.
Question
not rated yet May 25, 2011
Middle aged galaxy? Oh, we are all doomed!
that_guy
not rated yet May 25, 2011
The milky way is going to find a new girlfriend soon, so it can feel young again.

Unfortunately, it looks like the milky way is after a plumper, the Andromeda, and I'm sure that when it merges, it will shine bluer for a little while, but soon after it will have post coital regret.
spectator
3 / 5 (2) May 25, 2011
Any tiny little life forms from eithr galaxy had better have a new home by then.

youtube.com/watch?v=ws2V-Sv8-GQ

Binary Quasar superduperultramassive black hole of DOOOOOM...
CSharpner
5 / 5 (2) Jun 06, 2011
whilst the theory is blithely put forward as being infallible

You mean, like you do with a story written by men thousands of years ago with no scientific basis whatsoever, much of which has been disproven time and time again, yet you continue to repeat the same flaws over and over as being infallible?

Mathew 7:3 "Why do you see the speck that is in your brothers eye, but do not notice the log that is in your own eye?"

Practice what you preach, hypocrite! Yes, that's the first time I've EVER used that word against someone else, and I meant it.

Sorry, I know we're supposed to keep it civil and I'm trying... really I am, but this one just can't be left alone.