Nemesis: Sol's evil twin?

[Sampa]

Ok, astronomers have discovered that at least two thirds of the stars in the milky way are binary, meaning the stars,come in pairs. Some astronomers theorise that Sol, our sun, is no different, and that its twin is responsible for Earth's mass extinctions. What do you think? Does Nemesis exist?

Here's a video to start the discussion:

[_Augustus_]

Yes, I think it's there.

Neil Degrasse Tyson found a red dwarf in a star catalog that's 25 light-years away that no one else had heard of, and said DC Comics could have it become Superman's home star Rao.

There are many of those red dwarfs, but some don't even have their parallax/distance measured, and one of those is probably Nemesis.

Nemesis can not be a brown dwarf or gas giant because WISE was looking for those, whereas it wouldn't have cared about a red dwarf.

[Xannari Ferrows]

It makes sense to me that it's there. With enough debris surrounding it, it could be nearly indistinguishable from the spatial environment around it. The only way to know it's there is to get fairly close, and stare it in the face.

[Scotius]

Not that close to the Sun. Proxima Centauri, Barnard Star and other near red dwarfs are well known for many years. There is no way we missed a red dwarf at one light year or less. Give some credit to our astronomers and observatories

Cloud of debris still would be heated by a star in its centre, well above the normal temperature of space - and so it would be clearly visible to any IR telescope.

Edited August 25, 2015 by Scotius

[Sampa]

Yeah, for distance, astronomers theorize that Nemesis is only 1 LY from Sol

[lajoswinkler]

Yeah, for distance, astronomers theorize that Nemesis is only 1 LY from Sol

Which astronomers and based on what?

[Streetwind]

- A star would be visible because it would be undergoing fusion. Even extremely dim brown dwarfs are still fairly easy to detect if they're literally right next to us.

- If it's not undergoing fusion, it's not a star, it's a planet (a gas giant like Jupiter). In that case, our solar system would not be a binary system.

- An object of the mass of a star or near-star would significantly perturb the orbits of the objects in the solar system, and would cause the Sun to wobble significantly. Case in point: the entire Kuiper Belt and the Scattered Disc are what they are because of Neptune's gravity, and Jupiter has such a large influence that the Sun and Jupiter actually revolve around a common barycenter that lies above the Sun's surface. And Jupiter is still far away from being massive enough to approach fusion ignition.

Because orbital perturbations are very precisely measurable, scientists have already ruled out with confidence that an object massive enough to be a gas giant or greater exists anywhere within 2 lightyears of our Sun.

TL;DR: Nemesis does not exist today. If it existed in the past, it was so long ago that we cannot trace its existence.

We have, however, found a red dwarf star on a trajectory around the galactic center that, if traced back, makes it likely that it passed within 0.8 light years of our Sun a mere 70,000 years ago. It would have plowed straight through the Oort cloud and probably sent a lot of long period comets inwards. However, that event would be too recent to be involved in any mass extinctions. IIRC, no such event happened since the Yucatan meteor impact 65 million years ago.

Edited August 25, 2015 by Streetwind

[_Augustus_]

Yeah, for distance, astronomers theorize that Nemesis is only 1 LY from Sol

That is because they are correct.

Assuming that Nemesis is .09 solar masses and it's orbital period is 26 million years, it's semi major axis is 1.4283 light-years.

It's apparent magnitude at that distance is 6, which means it has to have an eccentric orbit!

At a distance of 2.6 light-years, it has an apparent magnitude of 7.3. That means that if you were Chuck Yeager, were at the best dark sky park, and knew where it is in the sky, you would hypothetically be able to see it.

Plausible, as no one knows where it is in the sky, and no one who goes to a dark sky park looks for it anyway.

This means that it has an orbital eccentricity above 0.8, which brings it as close as 0.2 light-years to the Sun, which is also perfectly plausible!

Edited August 25, 2015 by _Augustus_

[PB666]

Ok, astronomers have discovered that at least two thirds of the stars in the milky way are binary, meaning the stars,come in pairs. Some astronomers theorise that Sol, our sun, is no different, and that its twin is responsible for Earth's mass extinctions.

I think that many stars pass within close enough proximity, including red-dwarfs and neutron stars that are no longer visible and these can ending up cause comets to be tossed. The question however, was the dinosaur killing asteroid a mush ball or a metalloid asteroid from the asteroid belt, there are lots of earth crossing asteroids that can do similar damage, but asteroids, as big as they may be, for example 67p would get torn into two pieces if it passed close enough to earth, or any planet, and over a few rotations around the sun it begins to disappear into gas and dust. Even on top of that, planetoids in the belt, a growing list of objects, can also toss the smaller roids from their orbits and once they get close to the giant planets they can be tossed in or out of the solar system.

So the problem with their hypothesis is

1. Is oort cloud objects a K/T impactor or is it the asteroid belt.

2. Are extra-systemic flybys the major creator of cometary orbits or are they generated by intra-orbital interactions

3. Are such orbital periods even competitive with other more frequent celestial flybys, there is one due every 10,000s of years at about 1 mly. Occasionally one will get even closer.

4. Just because other systems have 2 celestials capable of light producing fission, does not mean that our sun had to have had such a system,

This is a just so hypothesis, the odds of it being correct are very small.

[magnemoe]

That is because they are correct.

Assuming that Nemesis is .09 solar masses and it's orbital period is 26 million years, it's semi major axis is 1.4283 light-years.

Problem is that its an orbital telescope who scanned the entire sky and would found an Jupiter sized object out to 1 light-year away because of the IR radiation.

Was another tread about this, now at distances like an light-year or longer you will probably get other stars disrupting the orbit by getting to close from time to time during the 5 billion years.

[_Augustus_]

Problem is that its an orbital telescope who scanned the entire sky and would found an Jupiter sized object out to 1 light-year away because of the IR radiation.

Was another tread about this, now at distances like an light-year or longer you will probably get other stars disrupting the orbit by getting to close from time to time during the 5 billion years.

Yes, but it wasn't looking for M8-class red dwarfs that were already cataloged. That will escape notice.

However, the Gaia telescope should find it soon if it exists.

[KerikBalm]

So to summarize:

There is Zero evidence for this

The end

[MinimumSky5]

Yes, but it wasn't looking for M8-class red dwarfs that were already cataloged. That will escape notice.

However, the Gaia telescope should find it soon if it exists.

I think you are seriously underestimating how bright a red dwarf is. As has already been mentioned in the thread, a red dwarf would be visible to the naked eye at 1LY, and gravitational effects mean that we would defiantly know about it from the Suns motion. Also, infrared observatories find all sorts of things that they weren't meant to, like comets and asteroids. If nemesis existed, we would know about it.

[Sampa]

What about relative motion making it stationary and thereby unnoticable?

[MinimumSky5]

Betelgeuse doesn't have much apparent motion, and is very visible. Stars move so slowly, that apparent and relative motion have no effect on their visibility.

[Albert VDS]

Ok, astronomers have discovered that at least two thirds of the stars in the milky way are binary, meaning the stars,come in pairs. Some astronomers theorise that Sol, our sun, is no different, and that its twin is responsible for Earth's mass extinctions. What do you think? Does Nemesis exist?

Here's a video to start the discussion:

https://youtu.be/j1UE-8MkAIQ

You lost me at Sol...

https://en.wikipedia.org/wiki/Sol

Sol is the Latin name for the Sun.

[tkw]

oh gawd

[Sampa]

You lost me at Sol...

https://en.wikipedia.org/wiki/Sol

And i chose to use that name on purpose.

[Hagen von Tronje]

It's one of the more interesting and less implausible theories to have no particularly good evidence. It would certainly be neater than a pocket on a shirt if it were true.

[Bill Phil]

You lost me at Sol...

https://en.wikipedia.org/wiki/Sol

People can call it what they want. As long you understand it, it's correct.

[PB666]

I think you are seriously underestimating how bright a red dwarf is. As has already been mentioned in the thread, a red dwarf would be visible to the naked eye at 1LY, and gravitational effects mean that we would defiantly know about it from the Suns motion. Also, infrared observatories find all sorts of things that they weren't meant to, like comets and asteroids. If nemesis existed, we would know about it.

.

Luminosity would be much less, a small red dwarf has a lifespan many fold that of our sun, the intensity would be much less, but still at one light year a red dwarf would be as visible as mars. In the IR spectrum it would be one of the brightest objects that is not otherwise designated. The problem here is that if its close enough for the sun to hold it then we would see it, and its so far you couldn't see it then there is nothing to stop a passing star from ripping it from its orbit and tossing it into a galactic orbit that we never see again. So then you have to make the object smaller and give it an eccentric orbit, but even. IR object of jupiters size would be detected far out in the system. Eventually the object is squeezed out of the binary range into a big oort cloud object.

A big oort cloud object does what any other big object would do, it will clean the space in its orbit even an eccentric orbit.

I have to agree this argument is far fetched.

[lajoswinkler]

Yes, in infrared it would be 100% impossible to avoid. There is literally zero evidence to back this idea up.

[magnemoe]

Yes, in infrared it would be 100% impossible to avoid. There is literally zero evidence to back this idea up.

Its an old idea dating back before we had so good telescopes.

[Jovus]

Nemesis can not be a brown dwarf or gas giant because WISE was looking for those, whereas it wouldn't have cared about a red dwarf.

As someone who regularly uses that WISE survey, I can assure you that this is incorrect. There are plenty of red dwarfs in the data.

That said, I'm not weighing in on this topic by pointing that out. Nemesis could still be a red dwarf that WISE simply missed, just like it could also be a brown dwarf or superjovian that WISE simply missed. (Or mis-cataloged. Or glitched out on. Or is indistinguishable from data artifacts. Or or or.)

[Xannari Ferrows]

Nemesis could still be a red dwarf that WISE simply missed, ...

It's easy to miss what is right in front of you sometimes.