If galaxies were people
This is my first post in English. Today, my goal is to talk about an article from the Hubble Site News Center I have just read (it was released on sept. 30).
In astronomy, there is a saying:
Galaxies are like people. They're only normal until you get to know them.
This thought is what comes to you when you start studying the sky, just like the astronomers who used the Hubble Space Telescope for the ANGST* program.
This survey observed 14 million stars in 69 different galaxies situated in the Local Volume, a region of space centered on our Milky Way.
It's quite a big work to explore so many stars in such a wide area of our neighbourhood (the galaxy distances ranged from 6.5 million light-years to 13 million light-years), when you think that the Local Group spans across only 3 million light-years and contains a dozen of galaxies.
But watching nearby galaxies with Hubble's sharp eyes is the only way to resolve the brightness of extragalactic stars, which remain blurry when observed in distant galaxies.
It's also a way to determinate the history of the star formation regions within these galaxies, visible in high details.
Because of the fact that galaxies in the distant universe are seen in their young age (to look far is to look back in time), the stars in nearby galaxies are the fossil equivalent of the active star formation seen in distant galaxies.
By studying when and where all the stars in the local universe formed, the survey has been able to compare old and young galaxies, in order to reach a better understanding of the history of star formation.
The rich diversity of galaxies is an early result of the ANGST survey. Some galaxies are made up entirely of ancient stars, while others have been forming stars nearly continuously during their whole lives. There are even a few examples of galaxies that have only started forming stars in the recent past.
"With these images, we can see what makes each galaxy unique," said team member Benjamin Williams of the University of Washington. "When we look at the distribution and development of stars in each survey galaxy, we can learn how differences in the galaxies' histories have produced the diversity of galaxy shapes and colors."
Source:
When It Comes to Galaxies, Diversity Is Everywhere. Hubble Site, september 30 [viewed october 9].
(*) ANGST stands for ACS Nearby Galaxy Survey Treasury.
In astronomy, there is a saying:
Galaxies are like people. They're only normal until you get to know them.
This thought is what comes to you when you start studying the sky, just like the astronomers who used the Hubble Space Telescope for the ANGST* program.
This survey observed 14 million stars in 69 different galaxies situated in the Local Volume, a region of space centered on our Milky Way.
It's quite a big work to explore so many stars in such a wide area of our neighbourhood (the galaxy distances ranged from 6.5 million light-years to 13 million light-years), when you think that the Local Group spans across only 3 million light-years and contains a dozen of galaxies.
But watching nearby galaxies with Hubble's sharp eyes is the only way to resolve the brightness of extragalactic stars, which remain blurry when observed in distant galaxies.
It's also a way to determinate the history of the star formation regions within these galaxies, visible in high details.
Because of the fact that galaxies in the distant universe are seen in their young age (to look far is to look back in time), the stars in nearby galaxies are the fossil equivalent of the active star formation seen in distant galaxies.
By studying when and where all the stars in the local universe formed, the survey has been able to compare old and young galaxies, in order to reach a better understanding of the history of star formation.
The rich diversity of galaxies is an early result of the ANGST survey. Some galaxies are made up entirely of ancient stars, while others have been forming stars nearly continuously during their whole lives. There are even a few examples of galaxies that have only started forming stars in the recent past.
"With these images, we can see what makes each galaxy unique," said team member Benjamin Williams of the University of Washington. "When we look at the distribution and development of stars in each survey galaxy, we can learn how differences in the galaxies' histories have produced the diversity of galaxy shapes and colors."
Source:
When It Comes to Galaxies, Diversity Is Everywhere. Hubble Site, september 30 [viewed october 9].
(*) ANGST stands for ACS Nearby Galaxy Survey Treasury.