Milky Way 'seems as white as spring snow' from another galaxy

Our galaxy would appear like the shade of fine-grained spring snow in early morning light when seen from another galaxy, according to scientists.

The Milky Way is redder than most spiral galaxies, but when combined with its blue arms, its overall colour is white.

The Milky Way’s overall colour is about the shade of white halfway between an incandescent light bulb and the standard spectrum white on a TV.

“Understanding the colour of the Milky Way allows us to compare other galaxies to it because for most galaxies all we can measure is how bright they are and what colour they are. It’s really frustrating that that’s exactly what we can’t measure about the Milky Way from our position inside it,” astronomer Jeffrey Newman, with the University of Pittsburgh, told Discovery News.

The research found that the Milky Way is among the reddest of spiral galaxies, meaning that its star-forming days are coming to an end.

“It’s entering its retirement when it won’t make anything new,” Newman said.

Based on the type and number of its stars, the Milky Way turns out to be a very typical galaxy, the analysis shows.

“We find that the color, the spectrum of the Milky Way is very close to the average of all the galaxies we see,” Newman stated.

For the analysis, scientists combined data from about 1,000 galaxies that have a similar number of stars and similar star birthrates as the Milky Way out of nearly 1 million galaxies in the Sloan survey.

Overall, the light from the Milky Way closely matches the colour of a standard incandescent light bulb, well within the range of what the human eye perceives as white.

The research was unveiled Wednesday at the American Astronomical Society meeting in Austin.