And unfortunately, the helium atoms in liquid helium are right on top of each other.

We need helium, and the helium is what we really need to go deep.

This is late in the life of a star in its giant phase.

In the middle of stars, you're joining hydrogen together to make helium and then helium together to make carbon, to make oxygen, all the things that you're made of are made in the middle of stars.

In the upper part of the chromosphere helium becomes partially ionized.

Helium is a chemical element with symbol He and atomic number 2.

Other workers soon used the same technique to discover indium, thallium, and helium.

) For comparison, the Sun has an abundance of elements heavier than helium of about ZSol 0.0172 0.002.

Approximately 96 tonnes of superfluid helium 4 is needed to keep the magnets, made of copper clad niobium titanium, at their operating temperature of , making the LHC the largest cryogenic facility in the world at liquid helium temperature.

So, that's that process there. Deuterium and tritium goes together makes helium 5.

After about a few minutes, there was hydrogen and helium in the universe. That's all.

This may be caused by the disappearance of a helium convection zone near the surface.

I've always wondered whether the professionals, the real professional helium physicists, were just a little bit embarrassed by this.

It was later shown that the lines resulted from the presence of helium a gas that was discovered in 1868.

Vega has an unusually low abundance of the elements with a higher atomic number than that of helium.

Pressurized helium from a 35 liter tank is used to force fuel into the engine.

It is radioactive, decaying into helium 3 through β decay with a half life of 12.32 years.

So where you get slightly denser areas, gravity starts compacting clouds of hydrogen and helium atoms.

The observed helium to hydrogen ratio in Vega is 0.030 0.005, which is about 40 lower than the Sun.

For a star with less than 1.8 times the mass of the Sun, this will occur in a process called the helium flash.

In 1890 Joseph Lockyer, who discovered helium in the solar spectrum, proposed a meteoritic hypothesis for the formation and evolution of the Sun.

And you make if from lithium. That reaction at the bottom, that's lithium 6, plus a neutron, will give you more helium, plus tritium.

Red dwarf stars with less than 0.4 are convective throughout, which prevents the accumulation of a helium core.

When helium II boils, due to its high thermal conductivity it does not bubble but rather evaporates directly from its surface.

Ankaa is similar to many of the visible stars of the night sky, being an orange giant of relatively average stellar size.

At a certain point the helium at the core of the star will reach a pressure and temperature where it can begin to undergo nuclear fusion through the triple alpha process.

When liquid helium 4 is cooled to below 2.17 kelvins ( 271.17 C) it becomes a superfluid, with properties that are very unlike those of an ordinary liquid.

Eventually the core is compressed enough to start helium fusion, and the star now gradually shrinks in radius and its surface temperature increases.

This value is close to the protosolar helium mass fraction of , indicating that helium has not settled in its centre as it has in the gas giants.

Now, the reason we were able to come up with this is two key ideas One is that this is similar to a cryogenic Dewar, something you'd keep liquid nitrogen or liquid helium in.

And the element helium was discovered just by staring at the light from the Sun because some of those black lines were found that corresponded to no known element.

17O is primarily made by the burning of hydrogen into helium during the CNO cycle, making it a common isotope in the hydrogen burning zones of stars.

This showed that despite its overall rarity on Earth, helium was concentrated in large quantities under the American Great Plains, available for extraction as a byproduct of natural gas.

It is by far the most abundant of the two naturally occurring isotopes of helium, making up about 99.99986 of the helium on Earth.

Solid helium has a density of 0.214 0.006 g cm3 at 1.15 K and 66 atm the projected density at 0 K and 25 bar (2.5 MPa) is 0.187 0.009 g cm3.

He tried to solidify it by further reducing the temperature but failed because helium does not have a triple point temperature at which the solid, liquid, and gas phases are at equilibrium.

A 3He 4He dilution refrigerator is a cryogenic device that provides continuous cooling to temperatures as low as 2 mK, with no moving parts in the low temperature region.

So, you start with the Big Bang and you get hydrogen, and then you get helium, and then you get more complicated stuff, and you get planets forming and life is a common, planetary based phenomenon, in my view.

A few supernovae, such as SN 1987K and SN 1993J, appear to change types they show lines of hydrogen at early times, but, over a period of weeks to months, become dominated by lines of helium.

However, results for NGC 6543 broadly agree that, relative to hydrogen, the helium abundance is about 0.12, carbon and nitrogen abundances are both about 3 10 4, and the oxygen abundance is about 7 10 4.

Of the 2008 world helium total production of about 32 million kg (193 million standard cubic meters) helium per year, the largest use (about 22 of the total in 2008) is in cryogenic applications, most of which involves cooling the superconducting magnets in medical MRI scanners.