The Milky Way is warped?
Astronomers mapping the locations of one kind of variable star in the Milky Way have found that, based on that data, our galaxy appears to be warped.
To make the map, astronomers looked to its bright, pulsing stars called cepheids. These stars burn up to 10,000 times more brightly than the sun so they are visible from across the galaxy and through interstellar clouds of gas and dust. Crucially, cepheids are “standard candles”: Their light waxes and wanes at a rate that corresponds to their inherent brightness. Astronomers can combine their true brightness with their apparent brightness, measured from Earth, to calculate how far away they are. Using a 1.3-meter telescope at Las Campanas Observatory in Chile, astronomers monitored the steady pulses from more than 2400 stars and pinpointed their location on a 3D model of the galaxy.
…From above, the Milky Way can be seen as a spiral-shaped galaxy, but this spiral disk doesn’t sit flat on the galactic plane. The cepheid stars cluster along an S-shaped curve, showing that the Milky Way’s disk is more warped than previously thought.
The image above shows this warp, with the star indicating where the Sun is located. The green dots represent cepheid variable stars.
This science is good, but there are uncertainties. For example, a top view of the galaxy, showing the location in yellow of all the cepheids mapped, is to the right. Notice the strong bias to one side of the galaxy, where the Sun is located. Their information for the rest of the galaxy is very spotty.
The available data might show this warp, but I think it is premature to assume it accurately maps the entire shape of the Milky Way.
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 print edition can be purchased at Amazon or from any other book seller. If you want an autographed copy the price is $60 for the hardback and $45 for the paperback, plus $8 shipping for each. Go here for purchasing details. 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
Astronomers mapping the locations of one kind of variable star in the Milky Way have found that, based on that data, our galaxy appears to be warped.
To make the map, astronomers looked to its bright, pulsing stars called cepheids. These stars burn up to 10,000 times more brightly than the sun so they are visible from across the galaxy and through interstellar clouds of gas and dust. Crucially, cepheids are “standard candles”: Their light waxes and wanes at a rate that corresponds to their inherent brightness. Astronomers can combine their true brightness with their apparent brightness, measured from Earth, to calculate how far away they are. Using a 1.3-meter telescope at Las Campanas Observatory in Chile, astronomers monitored the steady pulses from more than 2400 stars and pinpointed their location on a 3D model of the galaxy.
…From above, the Milky Way can be seen as a spiral-shaped galaxy, but this spiral disk doesn’t sit flat on the galactic plane. The cepheid stars cluster along an S-shaped curve, showing that the Milky Way’s disk is more warped than previously thought.
The image above shows this warp, with the star indicating where the Sun is located. The green dots represent cepheid variable stars.
This science is good, but there are uncertainties. For example, a top view of the galaxy, showing the location in yellow of all the cepheids mapped, is to the right. Notice the strong bias to one side of the galaxy, where the Sun is located. Their information for the rest of the galaxy is very spotty.
The available data might show this warp, but I think it is premature to assume it accurately maps the entire shape of the Milky Way.
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 print edition can be purchased at Amazon or from any other book seller. If you want an autographed copy the price is $60 for the hardback and $45 for the paperback, plus $8 shipping for each. Go here for purchasing details. 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