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Nuradnan
2004-Feb-22, 06:07 AM
I am a new astronomy student. I am going to presentate my essay about Nemesis Theory to my lecturers. I have gathered many sources. But I still want to know more about it. Would you, well, anyone, give me more proof that the theory is right? Or wrong <_< ? Thank you.

GOURDHEAD
2004-Feb-22, 01:47 PM
A lengthy discussion can be found in earlier postings in this topic at:
BROWN DWARF (Brown Dwarf Apart of the Solar System... (Pages 1 2 ) ) dated 12-23-2003.

My guess is that if the sun has a brown, or even black (totally burned out star no longer radiating in the visible portion of the spectrum as opposed to a black hole), dwarf as a companion, the companion is in an orbit of low eccentricity thus not a nemesis. You may want to direct your thesis towards presenting evidence in favor of the inner solar system&#39;s relatively stability as a negation of Nemesis as a nemesis.

GOURDHEAD
2004-Feb-23, 12:52 PM
Here&#39;s a more complete reference to the earlier discussion of this topic:

Universe Today Forums -> Space and Astronomy -> Everything Else in the Universe (See page 3 for Brown Dwarf Apart of the Solar System.)

damienpaul
2004-Feb-23, 10:20 PM
Okay, I&#39;ll bite, what is the Nemesis Theory?

Duane
2004-Feb-23, 11:43 PM
The theory of Nemesis came from the finding by Raup & Sepkoski in 1984 that mass extinctions, like the one that killed the dinosaurs ~65 million years ago, occurred every 26 - 32 million years. Since the favored theory for the end of the age of dinosaurs is that an asteroid or comet impacted Earth, the periodicity suggested that something must affect comets in the Oort cloud that often.

Richard Muller and others hypothesized that a faint companion star, nicknamed Nemesis, that orbits the Sun in a slightly eccentric orbit every 26 to 32 million years, could be the explanation.

Many geologists are not convinced that mass extinctions are periodic, so the theory is not widely accepted. There were a number of searches started for a dim orbitting companion, but I haven&#39;t followed up to see if any are still going.

I think Muller&#39;s theory was only published in an issue of Scientific American. I don&#39;t think it was published anywhere else, at least no where I am aware of.

Planetwatcher
2004-Feb-24, 01:07 AM
Try this source here where I quote one of my own earlier postings.


Christine Lafon <clafon@cfa.harvard.edu> I contacted Christine Lafon of the Harvard-Smithsonian Center for Astrophysics concerning a Nemisis scare documented a few years earlier
I was satisfied with her responses to my inquiries. She may have what you are looking for as well.

Nuradnan
2004-Feb-25, 02:18 PM
Well, thank you. Just for a bit refreshment B) , Nemesis Theory is a theory saying that there is a star orbiting our Sun. Every 26 million years, the star, called Nemesis, gets the closest point to our Sun. That is the cause of periodical mass extinction.

Thank you for your help.