Bruce Baber (22 July 2011)
"In the 1980s the scientists called it Nemesis...and Isaac Asimov wrote a book about it"

 


Isaac Asimov wrote a fictional book called Nemesis in 1989.  No doubt he was influenced by the reports from several scientists who labeled a theoretical binary sun (a dwarf sun) and who dubbed the object Nemesis.

 

What to me is interesting is what Asimov wrote about Nemesis. 

 

"There was no reason to notice it.  No one looked at it.  It's in Earth's far southern sky, so that most of the telescopes in pre-Settlement days couldn't even point in that direction."

 

He went on and described it as an incoming threat to earth.

 

I'm only a third of the way through the book, but the similarities are pretty interesting.

 

Just thought you might want to make a trip to your local library and check it out.

 

YBIC

Bruce Baber

 

 

Getting WISE About Nemesis

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Cosmic Evolution
Posted: 03/11/10
Author: Leslie Mullen

Summary: Is our Sun part of a binary star system? An unseen companion star, nicknamed “Nemesis,” may be sending comets towards Earth. If Nemesis exists, NASA’s new WISE telescope should be able to spot it.


Size comparison of our Sun, a low mass star, a brown dwarf, Jupiter, and Earth. Stars with less mass than the Sun are smaller and cooler, and hence much fainter in visible light. Brown dwarfs have less than eight percent of the mass of the Sun, which is not enough to sustain the fusion reaction that keeps the Sun hot. These cool orbs are nearly impossible to see in visible light, but stand out when viewed in infrared. Their diameters are about the same as Jupiter's, but they can have up to 80 times more mass and are thought to have planetary systems of their own.
Image credit: NASA
A dark object may be lurking near our solar system, occasionally kicking comets in our direction.

Nicknamed “Nemesis” or “The Death Star,” this undetected object could be a red or brown dwarf star, or an even darker presence several times the mass of Jupiter.

Why do scientists think something could be hidden beyond the edge of our solar system? Originally, Nemesis was suggested as a way to explain a cycle of mass extinctions on Earth.

The paleontologists David Raup and Jack Sepkoski claim that, over the last 250 million years, life on Earth has faced extinction in a 26-million-year cycle. Astronomers proposed comet impacts as a possible cause for these catastrophes.

Our solar system is surrounded by a vast collection of icy bodies called the Oort Cloud. If our Sun were part of a binary system in which two gravitationally-bound stars orbit a common center of mass, this interaction could disturb the Oort Cloud on a periodic basis, sending comets whizzing towards us.

An asteroid impact is famously responsible for the extinction of the dinosaurs 65 million years ago, but large comet impacts may be equally deadly. A comet may have been the cause of the Tunguska event in Russia in 1908. That explosion had about a thousand times the power of the atomic bomb dropped on Hiroshima, and it flattened an estimated 80 million trees over an 830 square mile area.

While there’s little doubt about the destructive power of cosmic impacts, there is no evidence that comets have periodically caused mass extinctions on our planet. The theory of periodic extinctions itself is still debated, with many insisting that more proof is needed. Even if the scientific consensus is that extinction events don’t occur in a predictable cycle, there are now other reasons to suspect a dark companion to the Sun.

The Footprint of Nemesis

The smaller object in these two photos is a brown dwarf that orbits the star Gliese 229. Located in the constellation Lepus and about 19 light years from Earth, the brown dwarf Gliese 229B is about 20 to 50 times the mass of Jupiter. Image credit: NASA

A recently-discovered dwarf planet, named Sedna, has an extra-long and usual elliptical orbit around the Sun. Sedna is one of the most distant objects yet observed, with an orbit ranging between 76 and 975 AU (where 1 AU is the distance between the Earth and the Sun). Sedna’s orbit is estimated to last between 10.5 to 12 thousand years. Sedna’s discoverer, Mike Brown of Caltech, noted in a Discover magazine article that Sedna’s location doesn’t make sense.

"Sedna shouldn't be there,” said Brown. “There's no way to put Sedna where it is. It never comes close enough to be affected by the Sun, but it never goes far enough away from the Sun to be affected by other stars.”

Perhaps a massive unseen object is responsible for Sedna’s mystifying orbit, its gravitational influence keeping Sedna fixed in that far-distant portion of space.

“My surveys have always looked for objects closer and thus moving faster,” Brown told Astrobiology Magazine. “I would have easily overlooked something so distant and slow moving as Nemesis.”

John Matese, Emeritus Professor of Physics at the University of Louisiana at Lafayette, suspects Nemesis exists for another reason. The comets in the inner solar system seem to mostly come from the same region of the Oort Cloud, and Matese thinks the gravitational influence of a solar companion is disrupting that part of the cloud, scattering comets in its wake. His calculations suggest Nemesis is between 3 to 5 times the mass of Jupiter, rather than the 13 Jupiter masses or greater that some scientists think is a necessary quality of a brown dwarf. Even at this smaller mass, however, many astronomers would still classify it as a low mass star rather than a planet, since the circumstances of birth for stars and planets differ.

Getting WISE About Nemesis

print PDF Digg It
Cosmic Evolution
Posted: 03/11/10
Author: Leslie Mullen

Summary: Is our Sun part of a binary star system? An unseen companion star, nicknamed “Nemesis,” may be sending comets towards Earth. If Nemesis exists, NASA’s new WISE telescope should be able to spot it.


Size comparison of our Sun, a low mass star, a brown dwarf, Jupiter, and Earth. Stars with less mass than the Sun are smaller and cooler, and hence much fainter in visible light. Brown dwarfs have less than eight percent of the mass of the Sun, which is not enough to sustain the fusion reaction that keeps the Sun hot. These cool orbs are nearly impossible to see in visible light, but stand out when viewed in infrared. Their diameters are about the same as Jupiter's, but they can have up to 80 times more mass and are thought to have planetary systems of their own.
Image credit: NASA
A dark object may be lurking near our solar system, occasionally kicking comets in our direction.

Nicknamed “Nemesis” or “The Death Star,” this undetected object could be a red or brown dwarf star, or an even darker presence several times the mass of Jupiter.

Why do scientists think something could be hidden beyond the edge of our solar system? Originally, Nemesis was suggested as a way to explain a cycle of mass extinctions on Earth.

The paleontologists David Raup and Jack Sepkoski claim that, over the last 250 million years, life on Earth has faced extinction in a 26-million-year cycle. Astronomers proposed comet impacts as a possible cause for these catastrophes.

Our solar system is surrounded by a vast collection of icy bodies called the Oort Cloud. If our Sun were part of a binary system in which two gravitationally-bound stars orbit a common center of mass, this interaction could disturb the Oort Cloud on a periodic basis, sending comets whizzing towards us.

An asteroid impact is famously responsible for the extinction of the dinosaurs 65 million years ago, but large comet impacts may be equally deadly. A comet may have been the cause of the Tunguska event in Russia in 1908. That explosion had about a thousand times the power of the atomic bomb dropped on Hiroshima, and it flattened an estimated 80 million trees over an 830 square mile area.

While there’s little doubt about the destructive power of cosmic impacts, there is no evidence that comets have periodically caused mass extinctions on our planet. The theory of periodic extinctions itself is still debated, with many insisting that more proof is needed. Even if the scientific consensus is that extinction events don’t occur in a predictable cycle, there are now other reasons to suspect a dark companion to the Sun.

The Footprint of Nemesis


A recently-discovered dwarf planet, named Sedna, has an extra-long and usual elliptical orbit around the Sun. Sedna is one of the most distant objects yet observed, with an orbit ranging between 76 and 975 AU (where 1 AU is the distance between the Earth and the Sun). Sedna’s orbit is estimated to last between 10.5 to 12 thousand years. Sedna’s discoverer, Mike Brown of Caltech, noted in a

The smaller object in these two photos is a brown dwarf that orbits the star Gliese 229. Located in the constellation Lepus and about 19 light years from Earth, the brown dwarf Gliese 229B is about 20 to 50 times the mass of Jupiter. Image credit: NASA

Discover magazine article that Sedna’s location doesn’t make sense.

"Sedna shouldn't be there,” said Brown. “There's no way to put Sedna where it is. It never comes close enough to be affected by the Sun, but it never goes far enough away from the Sun to be affected by other stars.”

Perhaps a massive unseen object is responsible for Sedna’s mystifying orbit, its gravitational influence keeping Sedna fixed in that far-distant portion of space.

“My surveys have always looked for objects closer and thus moving faster,” Brown told Astrobiology Magazine. “I would have easily overlooked something so distant and slow moving as Nemesis.”

John Matese, Emeritus Professor of Physics at the University of Louisiana at Lafayette, suspects Nemesis exists for another reason. The comets in the inner solar system seem to mostly come from the same region of the Oort Cloud, and Matese thinks the gravitational influence of a solar companion is disrupting that part of the cloud, scattering comets in its wake. His calculations suggest Nemesis is between 3 to 5 times the mass of Jupiter, rather than the 13 Jupiter masses or greater that some scientists think is a necessary quality of a brown dwarf. Even at this smaller mass, however, many astronomers would still classify it as a low mass star rather than a planet, since the circumstances of birth for stars and planets differ.