Celestia Forums

Hello

At first a little astronomy from Wikipedia.
Nemesis is a hypothetical red dwarf star or brown dwarf, orbiting the Sun at a distance of about 50,000 to 100,000 AU, somewhat beyond the Oort cloud. Richard A. Muller suggests that the most likely object is a red dwarf with magnitude between 7 and 12.
According to the hypothesis, Nemesis periodically (roughly every 26 million years) passes through a denser region of the Oort cloud, disrupting the orbits of comets, and sending millions of comets into the inner solar system and potential collision with the Earth. The last major extinction period was about 5 million years ago, so Muller posits that Nemesis is likely 1-1.5 light years away at present, and even has ideas of what area of the sky it might be in (supported by Yarris, 1987), near Hydra, based on a theoretical orbit derived from original apogees of a number of atypical long period comets that describe an orbital arc meeting the specifications of Muller's theory. It was initially nicknamed the "death star", after the fictional Star Wars weapon, although this nickname has fallen out of usage.
No direct proof of the existence of Nemesis has been found, however, and the existence of a periodicity in the Earth's series of mass extinctions is disputed. Muller has proposed that, based on analysis of lunar rocks that indicate the impact history of the Moon, a major uptick in lunar impacts 400 million years ago (mya) represents a major shift in the orbit of Nemesis into its present rather eccentric orbit, which according to Piet Hut will only be stable for another billion years.

Now you know what is Nemesis. Would you like to create a Nemesis model for the Solar System? It's easy .
Create a .ssc file with this informations

"Nemesis" "Sol"
{
Texture "browndwarf.jpg"
Radius 50000
Emissive true
Color [ 1 0.5 0.5 ]
EllipticalOrbit {
Period 200000
SemiMajorAxis 40000
Eccentricity 0.437
Inclination 06.18
AscendingNode 133.51
ArgOfPericenter 256.42
MeanAnomaly 241.70
}
RotationPeriod 20
}

http://img105.imageshack.us/my.php?image=nemesisdv6.jpg

Remember that the file is not accurated 100% and has fictional infos .

I have always liked the idea of the Nemesis Star. So many other stars have binary companions that it would make sense that Sol does as well. However last that I heard the most probably reason for the cyclical mass extinction is do to the oscillation of the sun as it moves up and down the galactic plain. This oscillation I believe occurs at the same rate as the proposed Nemesis Star. I guess we will find out it exists with in the next few years as our detection methods improve. If it does really exist, this might be the best candidate for an extra sol launch in my opinion.

Keep up the good work

-Matt-

http://en.wikipedia.org/wiki/Nemesis_%28star%29

Nemesis has always been a fascinating idea to me as well, but I just can't see how such a distant companion could remain gravitationally bound to Sol over its 4.5 billion year history.

...John...

Comets that come in from the Oort Clout have been bound to the sun for 4.5 billion years, why not something more massive?

Yes, but Nemesis was postulated to extend outward beyond the Oort Cloud, out to nearly half the distance to Proxima, if I remember correctly.

...John...

Hello

Yesterday i create a better and realistic version of Nemesis. Delete the above .ssc file and create a .stc file with this informations.



Click here to see an image. I hope that you like it

Now i have a little question. How about... planets orbiting around Nemesis?

Unfortunately, your Web site requires a login. At least, I think that's what it's asking for. I can't read Greek.

To add planets you need to create an SSC catalog file. A simple example is in http://www.lepp.cornell.edu/~seb/celest ... intro.html
More examples are in Celestia's \data\ directory: exoplanets.ssc and solarsys.ssc

selden wrote:Unfortunately, your Web site requires a login. At least, I think that's what it's asking for. I can't read Greek.

Very strange that . I hope that now you can see the image.
http://www.terring.ornicom.gr/index2.ph ... &task=show

selden wrote:To add planets you need to create an SSC catalog file. A simple example is in http://www.lepp.cornell.edu/~seb/celest ... intro.html
More examples are in Celestia's \data\ directory: exoplanets.ssc and solarsys.ssc

I know to create .ssc files . Maybe i was not understood at the first time. I just asked if will be a nice idea to put planet around Nemesis. I learn that red dwarfs can support planets, so why not Nemesis?

Your Nemesis looks OK now. You might want to consider painting a surface texture for it. My understanding it that brown dwarfs are expected to have significant turbulence -- i.e. cloud layers with gigantic storms, perhaps with the lower cloud levels glowing.

Planets sound reasonable to me, too.

You mean Iron Rain? Great idea , but i don't have the time and the tools i need to do this . Maybe sometime at Christmas.
As about the .ssc file, i think that 3 planets will be perfect. A Mercury-like, a Venus-like and a Saturn-like. I will make the .ssc file soon, maybe Saturday or Sunday.
It will be a great idea for a science fiction story, about the creation of colonies by Terrans or even aliens who study us from safer distance

Hello

A .ssc file with 3 planets and 2 asteroids orbiting around Nemesis is here. Just create a .ssc file with the Notebook with this info and save it into the "extras" folder.



I hope that you like it

Okay, I really like this subject. Yet, it is my firm analysis that Nemesis (perhaps: JRSN 2005-03-17) has a ~3642 year period. It swings out to the Oort Cloud and through the Kuyper Belt, and then swings back into the solar system between Jupiter and the Asteroid Belt.

Some of it's planetoids may at perigee, then, be quite close to Mars (say roughly between the A.B. and Mars), which may "fling" asteroids into our orbit. My information supports the idea that Nemesis is roughly a Saturn-class (1.24 S) brown-dwarf. There are two semi-large (~1/3 Neptune) [A,B] planetoids, 1 (~1.15 E) earth-class [C] body (Nibiru), 4 rocky moons [d, e, f, g], and an innumerable slough of asteroid-size satellites. I'd like to see just the seven major satellites. In order (distance in millions of Km from Nemesis), they are: d (45), C (85), e (125), f (155) , A (245), g (270), B (325), but this is not yet independently confirmed, and the two larger planetoids [A, B] may have several moons each.

This is unknown, by me, personally, and most of this information has been suppressed. I am working with covert methods of gaining information. It's a lot harder than I thought, previously, and this is SO hushed up, that I think I'm risking my safety, posting this information. And, my confidence level in my information is 85% accurate, and 15% critical averages and assumptions.

On a side note: Of course, Celestia doesn't show very many of the near-earth asteroids at all (why? It's a capable system.).

Now, it is an educated guess that Nemesis comes up from the solar south, at about ~-18 degrees from the solar plane. Has a mass of about ~3.5X Jupiter, and is really quite cold ~2500-3500*C. It currently is between the orbital distances of Saturn and Jupiter, and about ~2/3 of the way closer to Saturn, right now, and closing in on Sol. It should be here just in time for 2012, yea.

apogee ~4.5 x neptune,
perigee @ asteroid belt + ~25million Km.


Now, if someone could set up an .ssc file with those specifications, we'd have something. And, I would definitely download it.

-Craig Jones
Please, email me the .ssc file at craig.jones@live.com

craigjones wrote:On a side note: Of course, Celestia doesn't show very many of the near-earth asteroids at all (why? It's a capable system.).

Someone has to take the time to translate the asteroids' orbital parameters into Celestia's format. Since most of their orbits are perturbed by the Earth, simple Keplerian orbits would not be very accurate over a long period of time for many of them. XYZ trajectories would be required. The information is available from the Horizons ephemeris server, but, again, someone has to do the translation.

I wrote a web page long ago which describes how to translate the parameters provided in IAU circulars into Celestia's format.
http://www.lepp.cornell.edu/~seb/celest ... meris.html

You might want to consider translating the table of potentially dangerous asteroids which is provided by the Harvard-Smithsonian Center for Astrophysics at
http://www.cfa.harvard.edu/iau/lists/Dangerous.html
Their parameters aren't precise enough to do long-term predictions, but they'll give an idea of the distribution of those asteroids.

[edit]
Never mind. I've provided it as an Addon. See the thread viewtopic.php?f=6&t=13597
[/edit]


Please note that this is not the place to discuss the reality (or lack thereof) of Nibiru or other catastrophe or conspiracy theories. Any attempts to start such discussions will be summarily locked or deleted. Such discussions are welcomed at BAUT, however. http://www.bautforum.com/

Discussion of how one might determine the orbital parameters of an object which meets particular dynamical requirements is welcome, however, whether the object is real, hypothetical or imaginary.

Oh boy, how stupid i am? I forgot to report that the Nemesis addon is available at Celestia Motherlode. Just click here to download it. Special thanks to the people of Motherlode that accept my addon

i did a new Nemesis Add-on an is good

and hers my Celestia Image

tell me if u like it

Hey. very nice

o ya the textures...

is sedna a planet of Nemesis it relly look like it

"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.”

and it told that sedna is not from ar Solar System (Sedna could have formed around a brown dwarf about 20 times less massive than the Sun and have been captured by the Solar System when the brown dwarf passed through it)
look in wiki at : http://en.wikipedia.org/wiki/90377_Sedna

or at : http://en.wikipedia.org/wiki/Nemesis_(star)

the brown dwarf must be Nemesis

sedna is made from the same material of objects nearer the Sun like Mercury Venus Earth & Moon Mars and ceres

Instead of creating an SSC file for Nemesis you could easily create an STC file:

I just took the orbit parameters from Sedna and adapted them for this star.