Planets form twice for old stars

[brellis]

BBC Article <br /><font color="yellow">Two old stars may be undergoing a second episode of planet formation, long after their initial window of opportunity.<br /><br />Astronomers believe the stars once had orbiting companions, but that these were engulfed when the stars expanded.<br /><br />This caused matter to be ejected from the stars, forming a disc of gas and dust from which planets can form.<br /><br />Details were presented at the 211th American Astronomical Society meeting in Austin, Texas.<br /><br /></font><br />My rambling reaction - cool. Our models for planetary formation are going to get more complex. There are many scenarios where a binary companion gets engulfed into a larger solar system. When I was a kid, I wondered if Jupiter was a failed star that got captured before accreting enough material to become a binary companion star. <br /><br />The first extrasolar planets we detected were "hot" jupiters. When our sun turns into a red giant, our Jupiter will get a lot hotter itself. The scenarios we use to determine the possiblity of life forming on extrasolar planets must encompass these time-sensitive variables. <br /><br />Edit: is it possible that when our sun is an expanding red giant, it might trigger another episode of chaotic activity that might warm up a Jovian or Saturnian moon? Could the Kuiper/Oort belts get drawn into play, forming a new planet? <div class="Discussion_UserSignature"> <p><font size="2" color="#ff0000"><em><strong>I'm a recovering optimist - things could be better.</strong></em></font> </p> </div>

 

[schmack]

<font color="yellow">is it possible that when our sun is an expanding red giant, it might trigger another episode of chaotic activity that might warm up a Jovian or Saturnian moon? Could the Kuiper/Oort belts get drawn into play, forming a new planet? </font><br /><br />Are you asking this with the thought in mind of humans being able to flee to, and settle on, this moon or planet?<br /><br />This planet or moon would surely form over thousands and thousand if not millions of years. (if it did happen) and humans would most probably be a long way from restricted to this solar system by then. provided we had survived that long. <br /><br />but i am interested to hear if it is possible or not. becauseif its possible it would implicate an even greater chance of survival for an intelligent and technological species living in an unstable or lifes end star system. <div class="Discussion_UserSignature"> <p><font size="4" color="#ff0000"><font size="2">Assumption is the mother of all stuff ups</font> </font></p><p><font size="4" color="#ff0000">Gimme some Schmack Schmack!</font></p> </div>

 

[brellis]

<font color="yellow">Are you asking this with the thought in mind of humans being able to flee to, and settle on, this moon or planet? </font><br /><br />Not initially, but now that you mention it... <img src="/images/icons/wink.gif" /><br /><br />There have been other sightings of debris disks surrounding binary systems. <div class="Discussion_UserSignature"> <p><font size="2" color="#ff0000"><em><strong>I'm a recovering optimist - things could be better.</strong></em></font> </p> </div>

 

[h2ouniverse]

Hi,<br /><br />Actually the first exoplanets detected in 1992 orbit a pulsar, and have been suggested to have formed after the star's death.<br /><br />As far as KBO are concerned, the point is the cumulated mass, that is for now assumed to be about as low as 0.1 Earth masses (with huge uncertainty though). Spread over hundreds of thousands of cubic AUs, that leaves not much material.<br /><br />For OCO that lie hundreds or thousands of AU from Sun, the Red Giant phase should not make such a difference...<br /><br />Best regards.

 

[brellis]

If the mass of Saturn's rings was recently upped to 3 times the previous estimates, there may in fact be more faint matter out there than 0.1 earth mass, but what you say is true. It's all really far apart. IIRC the Voyagers and Pioneers encountered one KBO between them.<br /><br />To rephrase my question, I'm just curious what kind of event might draw more of the KBO/Oort material back into play. As the sun turns into a Red Giant, will its effect on planetary orbits change? Besides, of course, the inner planets it engulfs. <img src="/images/icons/wink.gif" /> <br /><br />In the earlier stages of our solar system's formation, big chaotic events occurred like what created our moon, what might have killed Mars, maybe even something that triggered the runaway greenhouse on Venus, and what caused Neptune to drift outside the orbit of Uranus.<br /><br />Now, it seems less likely that our solar system can be thrown back to that level of chaos - unless it gets triggered by something really big, like a close encounter with another star, or if a decent-sized rogue planet showed up. <br /><br />Is it even remotely possible that an unseen Nemesis is lurking? <div class="Discussion_UserSignature"> <p><font size="2" color="#ff0000"><em><strong>I'm a recovering optimist - things could be better.</strong></em></font> </p> </div>

 

[3488]

PSR B1257+12 in Virgo including the smallest known exoplanet.<br /><br />Also PSR B1620-26 within the M4 Globular Cluster in Scorpius.<br /><br />Andrew Brown. <div class="Discussion_UserSignature"> <p><font color="#000080">"I suddenly noticed an anomaly to the left of Io, just off the rim of that world. It was extremely large with respect to the overall size of Io and crescent shaped. It seemed unbelievable that something that big had not been visible before".</font> <em><strong><font color="#000000">Linda Morabito </font></strong><font color="#800000">on discovering that the Jupiter moon Io was volcanically active. Friday 9th March 1979.</font></em></p><p><font size="1" color="#000080">http://www.launchphotography.com/</font><br /><br /><font size="1" color="#000080">http://anthmartian.googlepages.com/thisislandearth</font></p><p><font size="1" color="#000080">http://web.me.com/meridianijournal</font></p> </div>

 

[h2ouniverse]

In reply to:<br />----- the mass of Saturn's rings was recently upped to 3 times the previous estimates --------<br /><br />I was not aware of that. Thanx for info. Actually I think the mass of KB is underestimated, and would expect a factor of 10. We will see when PanStarrs is operational (for objects mag<24) and when a space telescope is able to infer dust / pebbles density from infra-red measurements. Another possibility might be the long-term survey of star occultations as the one that already triggered doubts about actual density (X1 Scorpii).<br /><br />I wonder if New Horizons will be able to carry out survey to detect pebbles close to it (pebbles 10m-sized e.g. are far too small to be detected individually from ground, and far too sparsely distributed to be detected collectively through their IR glow by a space telescope).<br /><br /><br />in reply to <br />-------- Is it even remotely possible that an unseen Nemesis is lurking--------<br />Apparently astronomers have not given up. Pan-Starrs might detect close brown or red dwarves. Including a high magnitude companion to the Sun.<br /><br />IIUC the colllective mass integral distribution is expected even as a function of the logarithm of individual mass or of 3 times the decimal logarithm of diameter.<br />I.e the cumulated mass of 100km-ranged objects is roughly the same as the cumulated mass of 10km-ranged objects and as the cumulated mass of 1km-ranged objects (provided that you place the boundaries of your count in a regular logarithmic pattern, in that case from 1/sqrt(10) to sqrt(10) ).<br />There is a lower limit to that, due to accretion and to depletion by solar wind at dust grain level. But should be quite true from say 0.01m-range to 1000km-range. (nine decimal orders).<br />As a result, assuming similar densities, you have one billion 1km-sized objects for every million 10km-sized objects, or every thousand 100km-sized obj, or every 1000km-sized object. <br />This is for minor planets.<br /><br />A similar ru

 

[brellis]

hi <i>l'eau</i> <img src="/images/icons/smile.gif" /><br /><br />We had a brief discussion thread of the Saturn Ring mass. Check the 4th post, hehe. <img src="/images/icons/wink.gif" /><br /><br /><font color="yellow">A similar rule seems to apply for star-massed objects.<br />The number of red dwarves is far larger than Sun-massed ones.<br />If you extrapolate, you would expect brown dwarves to be even more numerous than red dwarves.</font><br /><br />I was excited to hear about the confirmation of a huge halo of reddies around Andromeda.<br /><br />We already know that there is plenty of chaotic, retrograde motion among the spiral arms of our galaxy. Similarly, we know that some comets show up at wild angles to the ecliptic plane of our solar system.<br /><br />As we get better at seeing exoplanetary systems, we might be able to witness a solar system going through a mid-life crisis of sorts along the lines of the cataclysmic collision that transformed life on earth 160 million years ago.<br /><br /> <div class="Discussion_UserSignature"> <p><font size="2" color="#ff0000"><em><strong>I'm a recovering optimist - things could be better.</strong></em></font> </p> </div>

 

[h2ouniverse]

in reply to<br />-------<br />Check the 4th post, hehe<br />-------<br /><br />I checked. OMG. Went in by one ear and went out from the other, through my poor ageing brain.<br />Life is a series of little humiliations.<br /><br /><br />in reply to<br />-----------I was excited to hear about the confirmation of a huge halo of reddies around Andromeda---------<br />Interesting. So reddies form a halo...<br />And if cold brown dwarves, planemos of many sizes, hydrogen pebbles, tend to form more or less concentric halos, with a total mass per size quite constant we come to:<br />* as much mass in the form of reddies (Mt) as for K stars or G stars or F stars<br />* as much mass in the form of big brown dwarves (34 to 80 MJup) as in red dwarves<br />* as much mass in the form of small brown dwarves (13.6 to 34 MJup) as in red dwarves<br />* and so on ...<br />(I divides objects through a [1M; 2.5M] interval-pattern)<br /><br />If Mt is the cumulated mass of any [1M; 2.5M] mass interval, then you have about 10Mt of stars (from red dwarves to giant black holes).<br />And if you assume bodies can form with this distribution law down to say, 5e9kg (200m-diameter with density 1.2), then you have 50 Mt of non-stellar bodies.<br /><br />Hence a ratio of 50/10 = 5 times visible stellar matter.<br />Condensed enough so as to be fully transparent (no dust cloud effect on light absorption and negligible cumulated occultation surface) and...<br />Tending to form halos around galaxies.<br /><br />Sounds familiar? <br /><br />Of course the big IF is to assume that the mass distribution law that we observe for both [1e9kg; 1e21kg] range (asteroids and TNOs) and for stars [2e29kg; 2e32kg] is also true on large scale iinbetween, in the [1e21kg; 2e29kg] interval...<br />But isn't it less irreasonable than inventing particles?<br /><br />Best regards.

 

[brellis]

Many episodes of star formation occur during the life of a galaxy. A huge cloud of gas is heading towards the Milky Way that will likely spur a new generation of stars.<br /><br /><font color="yellow">A giant cloud of hydrogen gas is racing towards a collision with the Milky Way, astronomers have announced.<br /><br />Smith's Cloud, as it is known, may set off spectacular fireworks when it smacks into our galaxy in 20-40 million years.<br /><br />It contains enough hydrogen to make a million stars like the Sun, say experts, and its leading edge is already hitting gas from our galaxy.<br /><br />When it does hit, the cloud could indeed set off a new burst of star formation in the Milky Way.<br /><br />Details of the work, by a team at the US National Radio Astronomy Observatory and the University of Wisconsin-Whitewater, were unveiled at the 211th meeting of the American Astronomical Society in Austin, Texas. </font><br /><br />Regarding the unknown amount of really small, dark material surrounding our solar system, I'm trying to remember where I read this, but it is postulated that what COBE measures as clumps in the cosmic background may in fact be dust in the galactic neighborhood of our sun. <div class="Discussion_UserSignature"> <p><font size="2" color="#ff0000"><em><strong>I'm a recovering optimist - things could be better.</strong></em></font> </p> </div>

 

[h2ouniverse]

Actually I was bouncing on the notion of halo of red dwarves.<br />There is apparently a mechanism at play that makes it easier to form reddies than bigger stars at some distance from the nucleus. <br />I was just speculating that may be this mechniasm, or others, could favor accretion of brown dwarves or Jupiter-sized planemos or Pontic planets or icy dwarf planets or even 1km-sized chunks at even larger distances (favoring it over stellar formation).<br /><br />So even if such cold objects represent a low mass in the Solar System or Sun's neighborhood (which is still to be demonstraetd btw) because most matter there is captured in stars, you might have much larger densities in galactical halo.<br /><br />Also, if this is in the form of cm-sized, km-sized or bigger objects, you will detect them only through their gravitational influence. When they claim that there is little cold normal matter outside galaxy, they mean in fact "no cloud detectable by its own photons nor by the way it alters background photons properties". In case this matter is condensed into relatively large, very cold chunks, you will get:<br />* a negligible occultation ratio so no detectable alteration of background photons<br />* a self-glow from 10K or 20K bodies, in the very far infra-red, extremely difficult to spot even with space telescopes at such distances.<br /><br />Best regards

 

[brellis]

The stars they've found so far in the Andromeda halo are red giants, not dwarves. You're extrapolating (correctly, methinks!) that vaster numbers of smaller objects have accreted both around Andromeda and our own Milky Way without reaching a point where they can be detected or even inferred from earth.<br /><br />Makes sense. <img src="/images/icons/smile.gif" /><br /><br />Regarding dark matter and dark energy, I get from what little I've read that the mass and accelerated expansion of the universe requires a lot more than what you might get from unseen bits between the stars and galaxies. Thus, you get the bizarre world of dark matter and dark energy, which always leaves my hed spinning. <img src="/images/icons/tongue.gif" /> <div class="Discussion_UserSignature"> <p><font size="2" color="#ff0000"><em><strong>I'm a recovering optimist - things could be better.</strong></em></font> </p> </div>

 

[h2ouniverse]

Oops.<br />"Reddies" meant red giants and not red dwarves... Illustrates again the saying "from the confusion of words comes the confusion of ideas".<br /><br />In retrospect, I should have refused the idea that red dwarves are detected in another galaxy when we are not sure of their number in the very neighborhood of the Sun!<br /><br />However, I still keep by my count when extrapolating even-distribution of matter over different massed objects between the 1e21kg range and the [2e29kg-2e32kg] stellar mass range. [see above post, coming to a ratio of five between visible normal matter and cold undetected normal matter]<br />As for why matter would concentrate in some faraway places into planet or asteroid- massed objects rather than star-massed objects, well, I can think of several reasons. E.g. the presence of solid hydrogen far from galactic nuclei (where ambient radiative temperature is below 9K).<br /><br />We'll see...<br /><br />Best regards.

 

[brellis]

bbc article<br /><br />more food for thought:<br /><br /><font color="orange">The discovery of a large disc of dust around a binary star system could force astronomers to rethink their computer models of the Universe.<br /><br />Previous observations turned up no sign of the disc at WZ Sagittae.<br /><br />But data from Nasa's Spitzer infrared telescope confirmed there was much more to this object than previously thought.<br /><br />The discovery may have implications for the study of everything from supermassive black holes to the formation of planets.<br /><br />..."Firstly, discs are everywhere, from systems which are forming planets through to supermassive black holes in the centres of galaxies," he explained.<br /><br />Astronomers use the same computer models to analyse each of these disparate systems, and so the presence of an extra dusty disc could make a huge difference to their results.<br /><br />Infrared observations also provide information about distant galaxies, many of which are much fainter in visible light. If dust like that detected by the students and teachers is important in these galaxies too, then many of the results of those studies may need recalibrating. </font><br />New info is coming fastly and furiously! <div class="Discussion_UserSignature"> <p><font size="2" color="#ff0000"><em><strong>I'm a recovering optimist - things could be better.</strong></em></font> </p> </div>

 

[h2ouniverse]

SDC gives the info too finally...<br />http://www.space.com/scienceastronomy/080121-mm-old-stars.html

 

[gammarayburst]

I can’t imagine that stars would not be all the same age considered people believe in a Big Bang. Wouldn’t all the matter in the universe be the same age then? And wouldn’t the dust have been either engulfed or have produced the planets by now? Stupid to theorize that the matter is coming from another star when none is close enough to prove otherwise. Maybe matter is still being made. That would explain allot of scientific theories. <br /><br />My idea, M=E/C² or matter is created when energy slows below the speed of light. How could that happen if it were possible? Matter was found to be created near the magnetic reconnection or 90° to a stars magnetic equator like I theorized years ago. : http://www.msnbc.msn.com/id/23031710<br /><br />What do you think? Should we still believe in the first law of thermodynamics?

 

[brellis]

If you study the Big Bang theory, you will find that heavier elements didn't exist until first-generation stars imploded, collided and supernova'd.<br /><br />Our sun is a second-generation star that formed several billion years after the Big Bang. <div class="Discussion_UserSignature"> <p><font size="2" color="#ff0000"><em><strong>I'm a recovering optimist - things could be better.</strong></em></font> </p> </div>

 

[robnissen]

Today, there are numerous new stars being formed in the Orion Nebula. In addition, some of the contents of the sun will be recyled into new stars after the sun becomes a white dwarf in about 5 billion years.