Astronomers weigh in on Milky Way’s true colours


Astronomers have determined exactly what colour our home galaxy the Milky Way is – and find it is aptly named.

While it appears white from Earth, that is literally a trick of the light; the question is how it looks from outside.

A comparison of star types in other galaxies gives perhaps an unsurprising result: white. But not just any white: specifically, like spring snow at an hour after sunrise or before sunset.

The finding was announed at the 219th American Astronomical Society meeting.

“For astronomers, one of the most important parameters is actually the colour of the galaxy,” Jeffrey Newman of the University of Pittsburgh told BBC News.

“That tells us basically how old the stars in the galaxy are, how recently it’s been forming stars – are they forming today or did its stars form billions and billions of years ago?”

Of course, it is difficult to see the Milky Way from the outside, because we are on the inside.

“But it’s worse than that; not only are we looking at the Milky Way from the inside, but our view is blocked by dust,” Prof Newman told the meeting.

“We can only see about one or two thousand light years in any direction.”

Colour chart

So Prof Newman and his student Tim Licquia went about putting the Milky Way on the map of other galaxies that we can see from outside.

They gathered data from the Sloan Digital Sky Survey, with information on about a million galaxies.

They compared those data with what they knew about the total mass in the Milky Way, as well as the rate of star formation, looking for near matches among other galaxies.

For those most nearly matched to our own galactic home, the team took an average and came up with a precise measure of what colour it must be.

“The best description I can give would be that if you looked at new spring snow, which has a fine grain size, about an hour after dawn or an hour before sunset, you’d see the same spectrum of light that an alien astronomer in another galaxy would see looking at the Milky Way,” Prof Newman told BBC News.

This “colour temperature” is somewhere between that of an old-fashioned incandescent lightbulb and noon-time sunlight; both whites, but subtly different.

And what does the colour tell us about our Milky Way’s development – is it a cosmic newcomer or past its prime?

“It appears our Milky Way is on the road between those two stages – based on the colour we find, the rate of formation of stars has been declining over time,” Prof Newman said.


“The Milky way is in a very interesting evolutionary state right now.”

Source: BBC


Comments are closed

Represented By: www.bangladeshwebdesign.com ™ | www.yellowpage.com.bd ™ | www.dreamcelebrity.com ™ | www.learnwebonline.com ™ | www.womenalbum.com ™ www.onlineshopbd.com ™

best world news website, world news website, world news paper online, world mobile news, internet world news, world news services, world news on mobile, world news latin america, world news site, world news.org, bbc pashto news live, world business news, news agency, world news report, bond news, bond market news, currency news, world business news, economy world news, business world news, world news asia, world news middle east, world news mobile, online news, online newspaper world wide news media, asia world news, news in the business world, loan news, movie news, forex news, politics news, real estate news, insurance news, euronews, euro news russian, euronews.net, latest euro news, euronews live online, news magazine, business news world, british broadcasting service, world affairs, cnn arabic news, gold news, trade news, bbc pashto news, world business news, world news education, christian world news headlines, news portal, business news in asia, mobile world news, daily news, media news, bbc news Pashto, travel news, bdnews, Bangladesh news