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dx
2002-Mar-13, 01:56 PM
I read something regarding the sun being part of a two sun system. The other star deemed "Nemesis", which comes close to the sun every 26 million years. This causes space debris from the Oort cloud to rain down on earth and is responsible for mass extinctions. The article (I can't remember where it was from) stated that we are at the farthest point and Nemesis would not return for another 10 million years. It also stated that the existence of Nemesis could not be proven or falsified until it was closer. I was wondering if it is true that it may be out there, but nothing we do can prove/disprove it.

2002-Mar-13, 02:41 PM
<a name="20020313.8:22"> page 20020313.8:22 aka Sun : Star
On 2002-03-13 08:56, dx wrote: To: 7 KAN 2 CUMKU
NOT being a Astronomer, and NOT knowing Where stars are
This anyway. My Guess { The Sun } travels about its
orbit aaround the central portion of the
Milky Way Galaxy along with a group of other
Stars. The Other Big member of the Group?
Sirius and its companion B. Recently Sirius
folowed? by the Sun crossed the Galatic Equator South to North
about 10 mittion years ago and WE are now outbound from the galatic equator for 50 more MILLION years (60 total) to reach Galatic winter & an ice meterorite enconter = Ice Age [aka 1/4 of a 240,ooo,ooo. yr "Gal_Orb"

dx
2002-Mar-13, 04:09 PM
I'm not too familiar with HUb' speak but I think what your saying confirms that it could be possible. The main question is is it possible to measure the existence/non existence of this "partner".
Thanks

Donnie B.
2002-Mar-13, 09:19 PM
So far, "Nemesis" is just a hypothesis, based on a rather weak periodicity in extinction events.

If it exists at all, it hasn't been identified with any particular star (as far as I know). I think the originators of the hypothesis believed it was a brown dwarf or the cold "cinder" of a dead star, and therefore not easy to spot.

I think it's best to file this one under "interesting ideas but thin on evidence".

James
2002-Mar-13, 10:43 PM
On 2002-03-13 16:19, Donnie B. wrote:

I think it's best to file this one under "interesting ideas but thin on evidence".

Yeah, if we're at the 10 milliom year mark past the last one, give it 16 million years, and then we'll talk. /phpBB/images/smiles/icon_smile.gif

Bob S.
2002-Mar-14, 04:05 PM
What is the maximum distance an object could be if it has an orbital period of 26 Myrs? Until some infrared telescope spots the burned out cinder of a brown dwarf within that distance, HUb's theory (the solar system crossing the galactic plane with its higher stellar density that could disturb the Oort cloud) sounds as good as any.

Azpod
2002-Mar-14, 06:33 PM
On 2002-03-14 11:05, Bob S. wrote:
What is the maximum distance an object could be if it has an orbital period of 26 Myrs? Until some infrared telescope spots the burned out cinder of a brown dwarf within that distance, HUb's theory (the solar system crossing the galactic plane with its higher stellar density that could disturb the Oort cloud) sounds as good as any.



I'd be more inclined to believe HUb's theory than the Nemesis theory. From what I've heard about it, it'd be out to almost 1LY by now, but even at that distance, a brown dwarf would be detectable. Its IR emmissions would show up on the IR sky surveys that have been done in the recent past, and it would even likely be visible to the many sky surveys that have been done in the recent past. Unless it was black as charcoal and a cold as the background radiation (impossible for an object capable of doing what Nemesis is supposed to do), we would have seen it by now.