Nemesis-Sun Companion

[qso1]

I was never entirely convinced that Proxima Centauri was a part of the Alpha Centauri system due to its extreme distance from the main pair despite Proxima being mentioned as the third star in that system. It may be but I don't know if anyone has ever shown that conclusively. And if it is, as you mentioned, it might have been captured. <div class="Discussion_UserSignature"> <p><strong>My borrowed quote for the time being:</strong></p><p><em>There are three kinds of people in life. Those who make it happen, those who watch it happen...and those who do not know what happened.</em></p> </div>

 

[mikeemmert]

Capture's possible. I would think this would have to happen before it left the molecular cloud in which it formed, where it's crowded and (more importantly) relative velocities are relatively low. Once it gets away from it's birth cluster, not only are average relative velocities quite high, but there are also far fewer ojects around to get angular momentum transfered to them so that capture can be effected. Captures after leaving the birth cluster are highly unlikely.

 

[MeteorWayne]

Also relavant for the rest of the solar system objects.<br />Sedna for example. It is just mighty hard to explain how it got there.<br />If it's a capture, it's got to happen early while there's still mass around to distribute the energy.<br /><br />Or there's a Nemesis, which I think this thread has demonstrated is unlikely to be much larger than Jupiter, if it exists at all.<br /><br />Time will tell as we learn more. <div class="Discussion_UserSignature"> <p><font color="#000080"><em><font color="#000000">But the Krell forgot one thing John. Monsters. Monsters from the Id.</font></em> </font></p><p><font color="#000080">I really, really, really, really miss the "first unread post" function</font><font color="#000080"> </font></p> </div>

 

[mikeemmert]

Hello, qso1. I went to the GravitySimulator to get some figures to answer you rather than a bunch of arm waving. 15000 AU is not really a large binary star separation distance.<br /><br />One good measure of how stongly bound a star system is is orbital velocity. Proxima Centauri orbits at 350 meters per second <i>if</i> it is in a circular orbit. Another reason I went to do a GravitySimulation is that I had remembered many years ago that the estimate for Alpha Centauri C (Proxima's) orbital period was over a million years, which is at odds with what the Wiki article says. I got a million and a quarter years. The author of the article might have assumed a highly eccentric orbit, and as a matter of fact I would also assume it's in a highly eccentric orbit. But we can't assume Alpha Centauri C is at "aphelion" (apoaster is the correct term, but nobody knows that this is the farthest point of a generic orbit and most people know what aphelion is).<br /><br />I used a circular orbit for illustrative purposes. This gives an easilyl graspable number to determine gravitational field strength at a certain distance (15000 A.U.). I used a single two-solar-mass object to make the measurements easier and simpler. I had tried a binary but GravitySimulator measures velocity with respect to a specific object and the binary, of course, moves pretty fast. A little artificial, but it gives the same results. <br /><br />Instrumentation exists which can tell the velocity of a star radially from the Sun (directly towards or away from the Sun) down to 3 meters per second. That's a bit less than one percent (1%) of the circular orbital velocity of Proxima. In my browsing, which was not a full press search, of the Alpha Centauri literature, I haven't seen orbital elements for Proxima, and this is knowable with present day instruments. I kind of suspect nobody's looked. You'd think somebody'd do that just because Proxima Centauri is The nearest known star to the Sun.

 

[mikeemmert]

The best estimate for the mass of an undiscovered Nemesis object on this thread so far has been the Bhalerao and Vahia paper, which states that the largest object that can escape detection would have 44 Jupiter masses. They also determined that a thorough search in the 1.25 micron infrared J band would constrain the object at 28 Jupiter masses. I'll go with the J-band estimate, event though I don't think they've completed a survey down to 25th magnitude yet.<br /><br />Investigations by myself and J.D. Hill at Los Alamos National Laboratory have shown that the observed damage to the Kuiper belt must have been caused by an object larger than Jupiter, but not much larger, starting at about 3 Jupiter masses at a bare minimum but more likely about 10 Jupiter masses. <br /><br />Whilst typing this up, I decided to google the 2Mass project, which was an all sky search in the infrared J band (1.25 microns), the H band (1.66 microns) and the K band (2.16 microns). I have discovered that the survey was completed and that the limiting magnitude was 13.5. This means that the optical surveys have gone much deeper and would detect a larger object, so if there was a Nemesis with less than 44 Jupiter masses, it is highly unlikely that it has been discovered.<br /><br />stevehw (Hi, Steve <img src="/images/icons/smile.gif" /> ) may have believed there was a deeper infrared survey. I know I believed this. Unfortunately, this is an urban legend and is not true. So the possibility of a brown dwarf Nemesis remains.

 

[qso1]

mikeemmert:<br />Hello, qso1. I went to the GravitySimulator to...<br /><br />Me:<br />Thanks for going through the trouble. I recall the orbital period being something like a million years as well. But I wondered if that was ever tested in a gravity sim program or mathematically. That in part because like you. I too looked for detailed orbital parameters and found none.<br /><br />It could be that they were done so long ago that the information never made it to the web and all the books I have on astronomy are pretty general when talking of star systems.<br /><br />BTW, is this gravity sim a commercially available product? <div class="Discussion_UserSignature"> <p><strong>My borrowed quote for the time being:</strong></p><p><em>There are three kinds of people in life. Those who make it happen, those who watch it happen...and those who do not know what happened.</em></p> </div>

 

[MeteorWayne]

Wayne bows to your superior knowledge. <img src="/images/icons/smile.gif" /><br />I did not know off the top of my head how far down we had looked.<br />Thanks for digging up the facts.<br /><br />MW <div class="Discussion_UserSignature"> <p><font color="#000080"><em><font color="#000000">But the Krell forgot one thing John. Monsters. Monsters from the Id.</font></em> </font></p><p><font color="#000080">I really, really, really, really miss the "first unread post" function</font><font color="#000080"> </font></p> </div>

 

[witgenestone]

It's happening in 2008: http://www.imdb.com/title/tt0455856/<br /><br />"When a group of astronomers calculate a star is on a course to slam into Earth, a few days before, it's accompanying planet will first pass close enough to the Earth to cause havoc on land and sea. They set about building a rocket so a few selected individuals can escape to the planet."

 

[Boris_Badenov]

OMG I loved that movie!!!<img src="/images/icons/cool.gif" /> <div class="Discussion_UserSignature"> <font color="#993300"><span class="body"><font size="2" color="#3366ff"><div align="center">. </div><div align="center">Never roll in the mud with a pig. You'll both get dirty & the pig likes it.</div></font></span></font> </div>

 

[alokmohan]

Brown dwarf nemesis is stimulating.We are on the threshold of discovering more brown dwarfs.Brown dwarfs ,as you ,know ,are bodies between jupiter and star,in respect of mass.

 

[mikeemmert]

<blockquote><font class="small">In reply to:</font><hr /><p>For that reason most stars come into existence close enough to other stars to develop multiple star systems. <br /><br />This is very likely what created the Alpha Centauri system.<p><hr /></p></p></blockquote>I have to take this seriously.<br /><br />But right now my opinion on this is that Nemesis formed from approximately the same disc of gas and dust as the Sun. Theoretical modeling (by other people) of the collapse of molecular clouds into stars indicate that when the cloud starts fragmenting, it breaks in two; then the halves collapse, speeding up their rotation, until the fragments break in two; and so on and so on.<br /><br />Molecular clouds have a mass of between 50,000 and one million solar masses, usually. They create only a few hundred stars because the process is interrupted by those stars which have formed, i.e. the new stars blow the cloud apart with radiation pressure, stopping star formation.<br /><br />Star formation is not that well understood, the last I heard. Molecular clouds form from the tidal wave that we see as the spiral arms, which are marked by bright, newborn stars. (It's a true "tidal" wave, which is why that term was replaced in oceanography with "tsunami", anyway the Japanese theory had predictive power which has demonstratably saved lives). This compresses the normally very thin interstellar gas. Sometimes supernovae shock waves produce additional compression. Istotopic analysis of meteorites has demonstrated that the Sun's nebula was compressed by a supernovae, but it is thought that this is a minority cause of compression in the larger scheme of things.<br /><br />I wouldn't doubt that a cluster of stars would have many regions that undergo net compression from the radiation of surrounding ordinary stars. Thus, stars could form prestranded in orbit around other stars. So I have to take this seriously. It's a little beyond the scope of what I can model at this point.<br /><br />Tony Du

 

[mikeemmert]

Hello, SEARCH<br /><br />I went back over some of these posts this morning to cover the material I had skipped over, since our calculus class went over stuff I already knew. Most of what I wound up looking at was the Wide-Field Infrared Survey Explorer, or WISE.<br /><br />This important project is to complete the all-sky surveys at all wavelengths. 2MASS did the survey at wavelengths of 1 to 2 microns and could reach down to magnitude 13.5. WISE fills in the wavelength bands of 3.3, 4.7, 12 and 23 microns. These wavelengths are not visible from the ground because the atmosphere glows strongly here. The telescope has to be launched into space and they are using a relatively small Delta II rocket. It's cooled by hydrogen ice. It is esentially a repeat of the IRAS experiment, only infrared detectors have gotten considerably better over the years.<br /><br />My reading of the site was rather frustrating, since they gave sensitivity in a unit I am unfamiliar with which has units of ergs/cm^2/sec/oct. I don't know how that translates into magnitude and have run out of time to find out.<br /><br />The main question is, "Can WISE find Nemesis, if it exists?" Well, I have to guess a little, but unfortunately, the answer is "No", I think. The wavelenths are right, but the telescope is simply too small; it will take quite a light bucket to see the object, and the diameter of the WISE main mirror is only 40 cm. Another problem is the time of the exposures, only about 8.8 seconds per frame. The telescope is cooled by hydrogen ice and the ice will run out in 7 months. Besides, it's an all-sky survey, and it's a big sky.<br /><br />2MASS used bigger telescopes, longer exposure times, and only reached magnitude 13.5, which according to Bhalerao & Co. is not enough to uncover the object if it exists. It would be great if they repeat the survey again with a bigger rocket with more ice. Maybe some day...<br /><br />I think the only hope for finding Nemesis is a targeted search

 

[search]

Hello mikeemmert<br /><br />We have been talking about Mass limit on Nemesis from VarunBhalerao and M.N. Vahia. <br /><br />Before going further lets clarify this:<br /><br />Their document is based on one specific asumption: 27Myr period of hypotetical Nemesis.<br /><br />Based on this assumption, it is seen that the inner Lagrengian point of the interaction between the Sun and its companion is in the Oort cloud. From this we calculate the mass–distance relation for the companion. We then compute the expected apparent magnitude(visible and J band) for the companion using the models of Burrows(1993). We then compare this with the catalogue completeness of optical and infrared catalogues to show that the sun cannot have a companion of mass greater than 44Mjup(0.042Msun). <br /><br />Conclusion of their document:<br />We conclude that if the Sun? Nemesis system has a period of 27 Myr, the sun cannot have a companion /> 44 Mj up (0.042 Msun )<br /><br />With this in mind lets fine tune the important points:<br />1. Assumption: 27Myr period<br /><br />2. Calculation: calculate the mass–distance relation for the companion<br /><br />Distance: <br />We estimate the error in this limit as follows. Since the periodicity in the geological records is 27 million years, the sum of the perihelion and aphelion distance must be 180,000 AU from Kepler’s laws approximated for a low mass companion. Hence, if the object is in a highly elliptical orbit, the farthest the ob ject can be, is 180,000 AU from the Sun. If the object is presently at its aphelion distance, then the apparent brightness will be a factor of 4 less than the value calculated here, effectively increasing the apparent magnitude by 1.5. This shifts the cutoff to about 0.045 Msun (47 Mj up ). <br /><br />3. Compute the expected apparent magnitude(visible and J band for the companion using the

 

[alokmohan]

Brown dwarf is easier solution,I mean as a hypothesis.

 

[search]

Hello Alokmohan<br />The conclusion is a paste from the paper we have been discussing here but to avoid confusions I edited my post and changed that part.<br />Thanks anyway for your post

 

[alokmohan]

Whether you agree I like to know.Brown dwarf fascinates me.Hubble has discovered 16 new extrasolar planets on yhe edge of galaxy.Who knows if they would turn to be brown dwarf in future?

 

[mikeemmert]

<blockquote><font class="small">In reply to:</font><hr /><p>5. Conclusion from the above refered paper: sun cannot have a companion of mass greater than 44Mjup(0.042Msun) <br /><br />Now can you formulate your question and maybe paste the part concerning the units you were talking about? <p><hr /></p></p></blockquote>OK, here's my source on the 2 Micron All Sky Survey:<br /><br />"<font color="yellow">The scientific value of 2MASS is documented in over 400 publications based on early data releases made while the Survey was still underway (The 2MASS Sampler, First Incremental Data Release and Second Incremental Data Release). 2MASS provides: <br /><br /><br />An unprecedented view of the Milky Way, nearly free of the obscuring effects of interstellar dust, that is revealing the true distribution of luminous mass and thus the largest structures over the extent of the Galaxy. <br /><br />The first all-sky photometric census of galaxies brighter than Ks=13.5 mag, including galaxies in the 60°-wide "Zone of Avoidance," where dust within the Milky Way renders optical galaxy surveys incomplete. The final Catalog of />1,500,000 galaxies provides a rich statistical database, including photometric measurements in three wavelengths and a few structural parameters for large samples of galaxies in differing environments, measured at wavelengths which are sensitive to the stellar populations dominating the luminous mass. <br /><br />The statistical basis to search for rare, but astrophysically important, objects, which are either cool, and thus extremely red (e.g., extremely low-luminosity stars and brown dwarfs), or heavily obscured at optical wavelengths (e.g., dust-obscured AGNs and globular clusters located in the Galactic plane). <br />2MASS used two highly-automated 1.3 m telescopes, one at Mt. Hopkins, Arizona, and one at Cerro Tololo, Chile. Each telescope was equipped with a three-channel camera, each</font>

 

[search]

I will repeat what I said before so my position on this is clear:<br /><br />"The point I would like to make is regarding the fact that star movement is not necessarely the same at all times specially as you get further away from the center of the galaxy. Keplerian orbits can be found close to the center but in spiral arm like the sun this is not the case and the orbits of the stars must be determined by a natural orbit arount the galaxy center plus variations determined by other stars (including dwarfs). This is one of the reasons I am not so inclined to the ciclic events disrupting the Oort Cloud but a natural orbital ocurrance not ciclical determined by variation in stars orbits. Meaning a passing star and not a companion." <br /><br />Question:<br />Maybe what would be interesting to find is what were the stars position 65 million years ago and see if there was an influence in the Oort Cloud? <br /><br />So I do not disregard the Nemesis hypotesis but I am more inclined to normal random astroid impact event or influenced by a nearby passing star in the vicinity of the solar system.<br /><br />Considering the Speed of Sun and that:<br /><br />1 AU = 149.598×10^6 km<br />1 ly = 9.461×10^12 km = 6.324 x 10^4 AU<br />1 pc = 30.857×10^12 km = 3.262 LY = 206.265×10^3 AU<br /><br />Now calculate the distance traveled both by the sun during 65Myrs for the top speed 250 km/s and the lower speed 217 km/s and do not bother with any other factors. (just a rough calculation). <br /><br />Just use the present year for the seconds calculation and you will see for either case that is far enough distance traveled for many things to have happened...

 

[yevaud]

Phil mentions "When Worlds Collide"<br /><br />Phil Discusses "Deep Impact"<br /><br />Bad Science in Movies - an Article <div class="Discussion_UserSignature"> <p><em>Differential Diagnosis:  </em>"<strong><em>I am both amused and annoyed that you think I should be less stubborn than you are</em></strong>."<br /> </p> </div>

 

[rhm3]

Very interesting thread.<br /><br />I'm curious about this possible companion as well. I was reading on Muller's site that the LSST and Pan-Starrs telescopes should find Nemesis if it exists...so hopefully we'll have a definite answer within the next 10 years. <br /><br />Question...if there is a brown dwarf or red dwarf star at the fringe of our solar system...is it possible that it has its own set of planets? I think I read somewhere a while back about Sedna being a lost planet of Nemesis, very speculative at best though. But the idea makes you wonder if there's a bit more to our solar system than we think.

 

[mikeemmert]

The last I heard, Muller still thought Nemesis was a red dwarf. As has developed in this thread, existing surveys would have picked it up if that was so.<br /><br />I believe he based his mass of the hypothetical object on disturbance of the Oort cloud. Since the density of the Oort cloud is low, it would take a considerable amount of mass to do this. However, if Nemesis was perturbing the Kuiper belt instead, it could be much smaller, as little as three Jupiter masses with 10 - 44 more likely.<br /><br />At the time Dr. Muller proposed his theory, only two Kuiper belt objects were known, Pluto and Charon. The 1992 discovery of asteroid 15760 QB1 was the first in an avalanche of discoveries about the Kuiper belt. Recently the count of KBO's passed 1000, which gives a mathematically valid statistical base. Although there is at least one known flaw in the database, namely that the area in the plane of the ecliptic has been much more thouroughly searched than the region outside of that plane, and may have other subtle flaws, I think there is enough evidence to form tenative hypotheses.<br /><br />I haven't done such a thorough statistical analysis yet, but a glance at the evidence seems to show that the Kuiper belt has been perturbed by a massive object. The fact that it has not been completely disrupted shows that this perturbation must have started comparatively recently. Dr. Muller's estimate of 400 million years matches the results of my GravitySimulations (which used hypothetical objects).<blockquote><font class="small">In reply to:</font><hr /><p>Question...if there is a brown dwarf or red dwarf star at the fringe of our solar system...is it possible that it has its own set of planets? I think I read somewhere a while back about Sedna being a lost planet of Nemesis, very speculative at best though.<p><hr /></p></p></blockquote>I think Sedna and Buffy are very good evidence that Nemesis did ind

 

[mikeemmert]

Hi, SEARCH <img src="/images/icons/smile.gif" /><br /><br />I looked at your first Burrows link and it didn't link up. So I tried the second one and it linked sucessfully to a whole bunch of Burrows paper. I don't think I'll be able to get to them all.<br /><br />I have been suffering severe backache over the last couple of days and my calculus homework fell behind, so I'll have to be brief (calculus comes first).<br /><br />I read a 1997 paper first. That one stated that the "grey" models, i.e. that brown dwarfs radiate as blackbodies, was probably incorrect in the infrared. Several molecules, like water and methane and phosphine, absorb various infrared wavelegths. As a result, the blackbody model can be off, as much as orders of magnitude. The net result he got from all this is that the spectra of brown dwarfs would be considerably bluer than expected from the blackbody model (blue being relative, we're talking about infrared radiation here). I had guessed, based on an assumption of a blackbody, that the wavelengths between 5 and 35 microns would be the best to search for Nemesis, but apparently this is not so. Nearer infrared from 1.2 - 2.5 might work better.<br /><br />This might be good news since the technology is more accessible.

 

[MeteorWayne]

Sorry to hear about the backache. Makes it hard to think, much less about calculus. <img src="/images/icons/frown.gif" /> I know!<br /><br />This thread is probably more fun <div class="Discussion_UserSignature"> <p><font color="#000080"><em><font color="#000000">But the Krell forgot one thing John. Monsters. Monsters from the Id.</font></em> </font></p><p><font color="#000080">I really, really, really, really miss the "first unread post" function</font><font color="#000080"> </font></p> </div>

 

[alokmohan]

Percival Lowell talked of planet x.This was to explain perturbation of uranus.The problem remains same after discover of pluto.SEARCH HAS STATED SOMETHING.If correct we may discard nemesis.Or nemesis may be LOWELLS PLANET X.Or muller may be correct,nemesis is red dwarf star.But brown dwarf is more reasonable explanation considering the paucity of knowledge on brown dwarf.

 

[mikeemmert]

<blockquote><font class="small">In reply to:</font><hr /><p>The reason for this is that most stars come from collections of stars created from large nebulae, which due to probable pressure effects from supernovae nearby condense into stars very close to one another.<p><hr /></p></p></blockquote>In the interest of honest discussion, this article in Space.com bolsters the supernova compression theory. This is not really new work, but the author has been able to pin down the distance of the supernova a little better:<br /><br />"<font color="yellow">The Sun had sisters when it was born, according to new research, hundreds to thousands of them. <br /><br /><br />And at least one was a supernova, providing further support for the idea that there could be lots of planets around other stars since our solar system emerged in such an explosive environment. <br /><br /><br />"We know that the majority of stars in our galaxy were born in star clusters," said Leslie Looney, who arrived at the solar sibling finding along with his colleagues at the University of Illinois at Urbana-Champaign. "Now we also know that the newborn solar system not only arose in such a cluster, but also survived the impact of an exploding star. This suggests that planetary systems are impressively rugged and may be common in even the most tumultuous stellar nurseries." <br /><br /><br />The evidence for the solar sisters was found in daughters—such as decayed particles from radioactive isotopes of iron—trapped in meteorites, which can be studied as fossil remnants of the early solar system. <br /><br /><br />These daughter species allowed Looney and his colleagues to discern that a supernova with the mass of about 20 suns exploded relatively near the early Sun when it formed 4.6 billion years ago; and where there are supernovas or any massive star, you also see hundreds to thousands of sun-like stars, he said<br /><br />...<br /><br />When mass</font>