Garik fails to cite , for whatever reason it’s the same journal, the Chaussidon and Robert Nature paper 1999

http://www.nature.com/nature/journal/v402/n6759/abs/402270a0.html

At that time the existence of exo planets was conjectural. These authors presumed that the 140 fold enrichment of Li relative to a cosmic abundance of Li (unity or 1 part in 10^10 relative to H) in the Sun was due to a physical process of its destruction in the Sun. A chemical fractionation now appears highly relevant.

A good test would be to look for Li abundance in stellar systems that are binaries; the closest being Epsilon Ori that has a twin brown dwarf system amongst others.

Isn’t it more accurate to say:

“Somehow, having planets [of the limited characteristics we can currently detect] means a star loses its lithium. How the heck does that happen?”

I don’t know if anybody is suggesting the lithium-rich systems don’t have planets. Rather it’s that the planets we’ve found have not been in lithium-rich systems. It’s important to remember that we’re only able to detect a fraction of the possible varieties of planets (we can’t detect planets like many of the ones in our solar system yet).

The key point to note , is that meteorite Li isotope abundances in the solar sysyem are ca. 10^4 th fold that of cosmic abundance. The point is that Li doesn’t need to be destroyed but is fractionated instead . Li abundance is conserved throughout the stellar plus planetary system. Of course the long term fate of Li in the star may be destroyed by nucleosynthesis in hotter stars.

Hence, in a protostellar cloud, prior to stellar ignition, a chemical process operates whereby the molten chondrules of silicates and aluminates etc (mm size) form like rain droplets in terrestrial clouds, chelating the alkali metal ions that include the Li isotopes. Infact, fractionation of 6Li is less than 7Li in carbonaceous chondrites that display a mobile water phase. On Earth although Li is the rarest element in the universe, as an alkali metal it is fractionated into salt deposits, a water phase; the rain and oceans have leached it from the from the parent planetary mass . The rarest element, at little cost powers our laptops and mobiles. So , although it’s rare Bolivia has enough intermontane salt, largely sodium chloride, but with enhanced Li, to last decades, hopefully with recycling.

The first stars would lack the heavier elements, prior to later supernova debris which gradually enriches the H/He clouds. Clouds that lack refractories would display no lithium depletion. Clouds rich in supernova debris, from which the Solar System condensed, would fractionate Li into the dust that formed chondrules and then on to meteorite parent bodies and planets. The Earth is 36% Fe by mass; rocky planets are rich in heavy metals, silactes and aluminates. Lithium doesn’t promote planet formation. Planet formation ie. rocky planet generation requires supernoval debris and during the incandescense of planetary formation within the inner disk ALL metals chelate with undifferentiated materials ie. chondrites.

How much rocky planetary material resides within Gas Giants? I don’t know. By comparison of Earth mass with the Jovian planet masses ca. 1000/1 and densities it’s likely that the total rocky mass of the solar system isn’t many fold greater than the terrestrial planetary masses. It’s an interesting speculation that major Li depletion in stars could reflect the presence of rocky terrestrial type planets rather than generic planets that include Gas Giant planets. The process of depletion is more likely to be chemical in the proto nebula rather than physical destruction by a purely physical and tortuous process of enhanced convection.

Hence, in a protostellar cloud, prior to stellar ignition, a chemical process operates whereby the molten chondrules of silicates and aluminates etc (mm size) form like rain droplets in terrestrial clouds, chelating the alkali metal ions that include the Li isotopes. Infact, fractionation of 6Li is less than 7Li in carbonaceous chondrites that display a mobile water phase. On Earth although Li is the rarest element in the universe, as an alkali metal it is fractionated into salt deposits, a water phase; the rain and oceans have leached it from the from the parent planetary mass . The rarest element, at little cost powers our laptops and mobiles. So , although it’s rare Bolivia has enough intermontane salt, largely sodium chloride, but with enhanced Li, to last decades, hopefully with recycling.

The first stars would lack the heavier elements, prior to later supernova debris which gradually enriches the H/He clouds. Clouds that lack refractories would display no lithium depletion. Clouds rich in supernova debris, from which the Solar System condensed, would fractionate Li into the dust that formed chondrules and then on to meteorite parent bodies and planets. The Earth is 36% Fe by mass; rocky planets are rich in heavy metals, silactes and aluminates. Lithium doesn’t promote planet formation. Planet formation ie. rocky planet generation requires supernoval debris and during the incandescense of planetary formation within the inner disk ALL metals chelate with undifferentiated materials ie. chondrites.

How much rocky planetary material resides within Gas Giants? I don’t know. By comparison of Earth mass with the Jovian planet masses ca. 1000/1 and densities it’s likely that the total rocky mass of the solar system isn’t many fold greater than the terrestrial planetary masses. It’s an interesting speculation that major Li depletion in stars could reflect the presence of rocky terrestrial type planets rather than generic planets that include Gas Giant planets. The process of depletion is more likely to be chemical in the proto nebula rather than physical destruction by a purely physical and tortuous process of enhanced convection.

As to the surprise of finding hot jupiters, that was a real surprise at first, but in hindsight it is obvious: they’re the ones easiest to detect with current methods, so no wonder such planets were among the first to be detected.

Well, if it is indeed so that stars’ life cycle consumes lithium and produces heavier elements that does sound like an explanation that makes William of Ockam happy.

But without boron, we couldn’t have sodium borohydride, which is anything but boring!

@ 22. Keith Harwood & 30. Smoothie

Even if all the planets in our solar system were made completely of Lithium, it would amount less than 0.15% of the Sun’s mass.

Now there’s a freaky thought! What would an all lithium Earth be like I wonder?

Or, for that matter, an all lithium Jupiter, Pluto or Mercury?

An all Boron world,OTOH, I imagine would be pretty Boron-ing in its lack of diversity.

Even if all the planets in our solar system were made completely of Lithium, it would amount less than 0.15% of the Sun’s mass.

@31. MadScientist

While in general I agree with your point, I disagree with your application here because the goal is not to rack up as many exoplanets as possible, but to find an Earth-like planet. If you want an Earth-like you need to make long observations of sun-like stars (see the Kepler telescope). In an ideal world, you could look at every sun-like star in the sky. Instead, if we now have a method (assuming it continues to be true as we find more systems) that allows us to better select our initial targets, then it really is great.

I think we like to sometimes idealized science, forgetting that sometimes a theory can be true even if it’s not good.

Fusion power – Wikipedia, the free encyclopedia
“Consequently, the deuterium-tritium fuel cycle requires the breeding of tritium from lithium using one of the following reactions”
http://en.wikipedia.org/wiki/Fusion_power#D-T_fuel_cycle

Really, shouldn’t all second generation stars be short on lithium and rich in heavier elements? I just don’t see much of a mystery here.

It seems to me that the planets that are likely to be the most interesting – smallish rocky ones with long orbital periods (months rather than a mere handful of days) – are also those that are most difficult to detect.

So, the correlation could be the opposite of that claimed. I.e., we should be looking at lithium-rich stars to find Earth-like planets.

However, this falls down completely if you also accept the hypothesis that the best chance for life (and therefore interesting planets) is on small planets in systems that also have large planets.

Now just as our planet finding techniques are predisposed to finding heavy planets in close orbits, might it be that, with current techniques, it might be easier to find planets in Lithium poor stars? Perhaps the Lithium in the atmosphere muddies up the spectrum just a tad so that finding those periodic Doppler shifts becomes a bit harder. In other words, the stars light is better for planet finding.

I have a sentimental attachment to the star HIP 20740, aka HD 28113. In my fantasies, it’s the star I’ve chosen as my home. Why? G-class star, which is good for science fiction, and a perspective from which the relatively nearby Pleiades line up neatly against the Cygnus Rift, creating a rather pretty spectacle.

Now I’m wondering how much lithium it’s got.

Will I ever know?

So how about this (feel free to replace the “all”s with “most”s, etc.):
Suppose all stars studied started off with similar amounts (by % total mass, or whatever) of Li, and had a relatively even distribution of Li in the to-be-star + accretion disk. In each case, the star forms, destroying most of the Li there – most of the Li that would show up in the spectrum. So in every case, a large amount of the each systems’ Li is now in the accretion disk. Planets form, but sometimes in unstable orbits. If the orbits are unstable, the Li “stored” in the planets eventually reaches the surface of the star, increasing its Li, and showing up prominently in the spectrum. If the orbits are stable, this doesn’t happen, and the Li content of the star stays low. In the former case, we’d be less likely to detect a planet (there may be no planets left). In the latter case, we’d be more likely to detect a planet.

… depending on the size of the effect (how much more Li we talking about? enough that could be supplied by a few jupiter-sized planets? or am I a few orders of magnitude off?) this is my best guess for now. Seems more plausible than a star *losing* Li because of planets, the tugging of planets mixing things up in the star, etc. … but then, I’m not an astronomer.

2M 1207b or to give its full designation 2 MASSW J1207334-393254 is a strong candidate for the “first ever exoplanet imaged” honour – although contending claims have been made.
A brown dwarf sun about 25 Jovian masses, it has another object which is most likely a 5 Jovian-mass exoplanet (or perhaps another brown dwarf) orbiting it at a distance of 55 AU.
This probable exoplanet was photographed by a European-American team using the Yepun telescope at the Chilean European Southern Observatory on April 27th 2004.

For more info. on this see :

http://en.wikipedia.org/wiki/2M1207b (its wikipage)

http://www.space.com/scienceastronomy/050430_exoplanet_image.html (Candidates Debate – and contenders for first photo’d exoplanet honour)

&

http://www.eso.org/public/outreach/press-rel/pr-2005/pr-12-05-p2.html

(ESO press release.)

http://kencroswell.com/MWEdgePlanets.html

Except from there:

Talk about location, location, location. If the Sun had been born near the edge of the Galaxy, chances are neither the Earth nor life would have arisen. That’s the implication of the first search for planet-forming disks on the Milky Way’s outskirts.

The stars on the fringes of our Galaxy have little oxygen, silicon, or iron–chief ingredients of Earthlike planets–so astronomers have long doubted that life could exist there. Now they have solid evidence for their pessimism.

Also, isn’t there more lithium in brown dwarf stars than regular ones because they don’t destroy it quickly? I think that’s actually used as a test to decide if a given faint star is a red dwarf or a brown one.

So if brown dwarfs are *all* high in lithium is this useful when applied to them or, I’d think more likely, not? We know that at least some brown dwarfs have planets because, for instance, of the one that was imaged before Fomalhaut & HR8799 – 2M 1207 b.

Finally is anyone else having trouble with the links in this post? The first link isn’t working at all for me & the second caused my computer to come up with a warning about security saying I needed a password and username to access it and another link took me to an “ESO is rebuilding its web” page.