Astronomers catalog large ring systems surrounding 74 stars
Click for original image.
Using a variety of ground-based telescopes in many wavelengths, astronomers have now produced a detailed catalog of 74 stars with large dust rings similar to the Oort cloud that is believed to exist at the very outer fringes of our own solar system.
The image to the right, reduced to post here, shows all 74 stars.
The new gallery shows a remarkable diversity of structure in the belts. Some are narrow rings, while others are wider and could be categorized more as “disks” than “belts”. Moreover, some of the 74 exocomet systems have multiple rings or disks and some of those are “eccentric,” meaning not a circular orbit but more like an oval. This provides evidence that yet undetectable planets or perhaps moons are present and their gravity affects the distribution of pebbles in these systems.
You can read the paper here [pdf].
The press release implies the discovery of “exocomets” but that is not true. The belts and rings mapped are likely to have comets in them, but no such comets have been found.
The scientists say that this database can be used to better understand the formation of solar systems, though they also admit that the “limited (although much improved) size of our sample” makes any conclusions based on it very uncertain. They hope however that over time that sample size will grow.
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. from any other book seller, or direct from my ebook publisher, ebookit.
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
Click for original image.
Using a variety of ground-based telescopes in many wavelengths, astronomers have now produced a detailed catalog of 74 stars with large dust rings similar to the Oort cloud that is believed to exist at the very outer fringes of our own solar system.
The image to the right, reduced to post here, shows all 74 stars.
The new gallery shows a remarkable diversity of structure in the belts. Some are narrow rings, while others are wider and could be categorized more as “disks” than “belts”. Moreover, some of the 74 exocomet systems have multiple rings or disks and some of those are “eccentric,” meaning not a circular orbit but more like an oval. This provides evidence that yet undetectable planets or perhaps moons are present and their gravity affects the distribution of pebbles in these systems.
You can read the paper here [pdf].
The press release implies the discovery of “exocomets” but that is not true. The belts and rings mapped are likely to have comets in them, but no such comets have been found.
The scientists say that this database can be used to better understand the formation of solar systems, though they also admit that the “limited (although much improved) size of our sample” makes any conclusions based on it very uncertain. They hope however that over time that sample size will grow.
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. from any other book seller, or direct from my ebook publisher, ebookit. 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
Spectacular, I love the ones with the beautiful symmetry of a perfect circle.
In many pictures posted of other galaxies, frequently there are streaks and blobs in the frame similar to what’s pictured here. Now I will look at them in a new perspective.