A stellar interloper in the Milky Way?
The uncertainty of science: Astronomers have identified a star inside the Milky Way whose chemical compositions suggests it was formed and originally came from a nearby dwarf galaxy.
This is the first discovery of a star having such extreme abundance ratios among Milky Way stars. On the other hand, several examples of stars having similar abundance ratios are known in dwarf galaxies. This result suggests that this star has formed in a dwarf galaxy, and has accreted onto the Milky Way in the process of galaxy formation. The abundance ratios of this star provide the clearest signature of merger events of dwarf galaxies in stellar chemical abundances known to date.
Though presently unique, this star probably is not the only such interloper in the Milky Way. It is believed by astronomers that our galaxy has absorbed a number of dwarf galaxies as it formed and grew, so we should expect more such stars to be discovered with time.
At the same time, we also must exercise some skepticism. Our understanding of galaxy formation is very preliminary, and thus the astronomers might be assuming too much about the chemical composition of dwarf galaxies in coming to this conclusion.
Posted at Los Angeles Airport on my way to Cannon Beach, Oregon, for a short vacation with friends.
On Christmas Eve 1968 three Americans became the first humans to visit another world. What they did to celebrate was unexpected and profound, and will be remembered throughout all human history. Genesis: the Story of Apollo 8, Robert Zimmerman's classic history of humanity's first journey to another world, tells that story, and it is now available as both an ebook and an audiobook, both with a foreword by Valerie Anders and a new introduction by Robert Zimmerman.
The ebook is available everywhere for $5.99 (before discount) at amazon, or direct from my ebook publisher, ebookit. If you buy it from ebookit you don't support the big tech companies and the author gets a bigger cut much sooner.
The audiobook is also available at all these vendors, and is also free with a 30-day trial membership to Audible.
"Not simply about one mission, [Genesis] is also the history of America's quest for the moon... Zimmerman has done a masterful job of tying disparate events together into a solid account of one of America's greatest human triumphs."--San Antonio Express-News
The uncertainty of science: Astronomers have identified a star inside the Milky Way whose chemical compositions suggests it was formed and originally came from a nearby dwarf galaxy.
This is the first discovery of a star having such extreme abundance ratios among Milky Way stars. On the other hand, several examples of stars having similar abundance ratios are known in dwarf galaxies. This result suggests that this star has formed in a dwarf galaxy, and has accreted onto the Milky Way in the process of galaxy formation. The abundance ratios of this star provide the clearest signature of merger events of dwarf galaxies in stellar chemical abundances known to date.
Though presently unique, this star probably is not the only such interloper in the Milky Way. It is believed by astronomers that our galaxy has absorbed a number of dwarf galaxies as it formed and grew, so we should expect more such stars to be discovered with time.
At the same time, we also must exercise some skepticism. Our understanding of galaxy formation is very preliminary, and thus the astronomers might be assuming too much about the chemical composition of dwarf galaxies in coming to this conclusion.
Posted at Los Angeles Airport on my way to Cannon Beach, Oregon, for a short vacation with friends.
On Christmas Eve 1968 three Americans became the first humans to visit another world. What they did to celebrate was unexpected and profound, and will be remembered throughout all human history. Genesis: the Story of Apollo 8, Robert Zimmerman's classic history of humanity's first journey to another world, tells that story, and it is now available as both an ebook and an audiobook, both with a foreword by Valerie Anders and a new introduction by Robert Zimmerman.
The ebook is available everywhere for $5.99 (before discount) at amazon, or direct from my ebook publisher, ebookit. If you buy it from ebookit you don't support the big tech companies and the author gets a bigger cut much sooner.
The audiobook is also available at all these vendors, and is also free with a 30-day trial membership to Audible.
"Not simply about one mission, [Genesis] is also the history of America's quest for the moon... Zimmerman has done a masterful job of tying disparate events together into a solid account of one of America's greatest human triumphs."--San Antonio Express-News
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