So just over 30 years ago.

And by then astronomers were observing in the near infrared.

And so that's how a lot of HH objects are discovered.

Not in the optical because it's hard to see things when they're obscured by the gas in visible light.

But in the infrared you can peer through a lot of that obscuration.

So this is the discovery image.

And here's a more recent image.

I mean, it's still from the early 2000s, and you can see that HH211 jet, but there's also another jet coming from another protostar over here.

And so this region is just rife with lots of star formation.

And as far as what exactly is happening, this is kind of a cartoon showing how stars form.

And so we have a gas cloud, and then as parts of the cloud become unstable and collapse to form stars, you have gas flowing in and falling towards the center of regions that will eventually become a protostar.

And the gas piles up in an accretion disk, and some of that gas falls into the main star at the center.

and most of the gas actually gets ejected in these jets.

And so over time, what happens is not only does the gas funnel into the star

and the gas in the equation desk form the planets,

but the jets actually clear the surrounding cloud.

And so we think that star formation is actually self-limiting.

so that not all the gas can fall in because these jets basically disrupt the cloud.

You have this cloud that surrounds this protostar,

but over time the jets and the winds from this and other young stars

basically destroy the cloud from the inside out.

And so star formation, so we think that for a typical molecular cloud,

perhaps no more than about 5% of the mass

actually ends up in new stars.

So the big question is,

why do these jets form?

And this is something that astronomers

have grappled with for decades

because they started seeing evidence

for these jets

just from the shock to mission,

the Herbert Carra objects,

going all the way back to the 1940s and 1950s.

and people didn't really quite understand what they were

until they started doing spectroscopy in the 60s and 70s.

But it was clear that there was stuff happening

and there was a lot of activity in these clouds.

And so a big question is how do jets actually launch from the protostars?

And there have been a lot of theories over the last 30 or 40 years

But one of the prominent theories is something called the X-wind.

And basically, the idea is that you have a star at the center, and you also have an accretion disk.

And it turns out that the stars tend to have really strong magnetic fields.

So the younger the star, the more active it is, the stronger the magnetic field.

And the magnetic field can actually interact with the accretion disk

because when you have a field that's very strong,

the gas that collects due to that field at a certain point

has the same density as the gas coming in to the accretion disk.

And so that's the edge of the accretion disk,

which is truncated by the magnetic field.

It becomes kind of an interesting place where lots of things can happen.

And so this X-1 theory was proposed recently by Frank Hsu,

who is an astronomer at Berkeley.

And he and other and his colleagues worked on refining this model over many, many years.

And other people also worked on it.

But basically, the idea is that because of interactions between the field and the star

and the accretion disk, you basically have these field lines that originate at the edge

of the disk that come out in an X-like pattern.

And hence, that's why they call it an X-wind.

And so you have field lines that go out.

And as the star rotates with the field and the gas in the accretion disk is also orbiting,