Tag Archives: Andromeda

Astronomers roughly map out Andromeda’s history

The uncertainty of science: Astronomers have now roughly mapped out the history of the Andromeda galaxy, identifying two major events whereby it had absorbed nearby dwarf galaxies.

“It’s been known for 10 to 15 years that Andromeda has a vigorous history of accumulating and destroying its neighbours,” Mackey says. In fact, he says, “It seems to have a much more intense history of that than the Milky Way.”

…[New data] “tells us there were two main events that formed the halo of Andromeda,” Mackey says. “One occurred very long ago. The other must have happened relatively recently.”

Not that Andromeda couldn’t also have eaten innumerable smaller galaxies. ”We can’t trace them with galactic clusters, because they didn’t have any to begin with,” Mackey says.

Most of the news reports about this new research have been very overwrought (Andromeda is “violent” and is going to “eat us!”) and very unaware that the assimilation of nearby small galaxies by Andromeda is not really news. Astronomers have known for years that big galaxies like Andromeda and the Milky Way absorb the dwarf galaxies around them. All this story does is postulate a more detailed though very rough timeline.

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New Hubble images to celebrate its upcoming 25th anniversary

The Space Telescope Science Institute (STScI) that operates the Hubble Space Telescope yesterday released two spectacular new images at the January meeting of the American Astronomical Society.

They also announced new data from Hubble that suggests a major eruption had occurred at the center of the Milky Way about two million years ago.

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The Milky Way shrinks

The uncertainty of science: New research by astronomers suggests that the Milky Way is about half as massive as previously estimated.

In the sixties I remember astronomers claiming that the Milky Way was twice as big as Andromeda. Then it was considered half as big. Most recently it was considered about the same size. This new research makes it half as big as Andromeda again.

In other words, the data is very uncertain, and the scientists really don’t have a good handle on it. None of these conclusions should be taken very seriously. All we really know at this point is that the Milky Way and Andromeda are approximately comparable.

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Using the Hubble Space Telescope, astronomers have determined that the Milky Way and Andromeda galaxies are on a collision course, and will meet head on in 4 billion years.

Using the Hubble Space Telescope, astronomers have determined that the Milky Way and Andromeda galaxies are on a collision course, and will meet head on in 4 billion years.

You can download the science paper describing these results in detail here [pdf].

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