Lives of the Stars The Sky at Night


Lives of the Stars

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-BOTH: Hello.

-Welcome to Herstmonceux Observatory in East Sussex,

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with its collection of impressive

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and elegant domes. They still have working telescopes here

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and enjoy wonderful dark skies, so I'm told, when it's clear.

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Well, we hope to enjoy those dark skies a little later with

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the Wealden Astronomical Society, but until then,

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we're going to talk about the lives and dramatic deaths of stars.

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And the team are here too, having a tug-of-war.

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We'll find out why later.

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Herstmonceux was built after the Second World War

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and became a Royal Observatory in 1958.

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Many of the telescopes came from Greenwich,

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where the London light pollution had become too much.

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Sir Patrick Moore was a regular visitor

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and supporter of the observatory, using the telescopes

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to look at the moon. Here he is in 1984.

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Of course, there are some features of the observatory

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which everybody knows.

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There is, for example, the time department.

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And here, the atomic clocks

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are now better timekeepers than the Earth itself.

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And it's also from here that the six pips come out.

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LOUD PIP

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Then there are the telescopes of Herstmonceux,

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which is another reason for our being here.

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In its heyday, 200 astronomers worked here

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and they looked at galaxies, nebula and even comets,

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but the majority of their work was with the stars.

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They mapped the stars in the sky, measured their distances, brightness

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and studied the light to see what the stars are made of.

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Stars make up a family and, like any family,

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the members are different.

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-Some stars are big.

-Some small.

-Some bright.

-And some dim.

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But they're all essentially the same.

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They're vast balls of gas, mostly hydrogen.

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But the best star to look at is our own - the sun.

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And that's because, at the core of the sun, we know that

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the temperatures and the pressures are almost unimaginably vast.

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That means the atoms there are moving incredibly quickly.

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And when they collide, they can fuse together and as a consequence

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of the most famous equation - e=mc2 - matter is turned into light.

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And that happens at a furious rate. In fact, the sun is losing

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nearly 4 million tonnes of matter each and every second.

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So that's 4 million tonnes gone.

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And another 4 million tonnes gone.

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And that's happening all the time, in every one

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of the hundreds of billions of stars in our own galaxy.

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In fact, as stars go, the sun's not much to write home about.

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It's rather Mr Average. And so, it's time we met the rest of the family.

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There are hundreds of billions of stars in our own galaxy,

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but even from a good, dark spot,

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you'll have to content yourself with seeing just a few thousand of them.

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Even the largest telescopes won't show a star

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as anything other than a point of light, but we do see colour.

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Some stars are yellow, like our own sun,

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some red, and some blue.

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And it turns out that colour's important,

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because it tells us how hot the stars are.

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Lucie and I have come to a telescope

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that's spent many a night staring at the stars.

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Fantastic. So here we have the 1896 26-inch Thomson Refractor.

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-It's beautiful, isn't it?

-Fantastic.

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Always good to see a proper refractor in a giant dome.

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This is what observatories are supposed to look like.

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And they used to do measurements of star positions from here.

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And not just positions.

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This telescope was used to measure the distances to the stars.

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But that's not the most interesting thing about this telescope.

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It does something really special. Let me show you. Come round here.

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-OK, I'm slightly nervous.

-SHE LAUGHS

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When you start running for...for switches.

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-Hold onto your hats.

-OK.

-Here we go.

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LOUD THUD, CHRIS LAUGHS

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So we do not have to move the telescope. We go to the telescope.

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This is the civilised way to get to your observing position.

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Move the entire floor.

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-This is fabulous!

-LUCIE LAUGHS

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-But you need to watch out for your head, Chris.

-Right, thank you.

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I've been told it stops automatically. I'm just going

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-to keep pressing until it does.

-Are you sure this stops?

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I'm willing... Yes!

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-There we go.

-There we go.

-Perfect.

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-So what a civilised way to get up to do the observing.

-It's great.

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-And now, here we are and we can go look at the sky.

-Yeah, fantastic!

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Over 100 years ago, astronomers were trying to make sense

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of the assortment of stars in the night sky.

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Two men - American Henry Russell and Dane Ejnar Hertzsprung -

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realised that the key was showing

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how the brightness of a star is related to its colour.

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So what we've got here are the two things we know about stars.

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We've got their colour, but colour means temperature,

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so the red stars are the coolest

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and the blue, white ones are the hottest.

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It's the opposite way round from bathroom taps.

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Red is cool, blue is hot.

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And the other piece of information is how bright the star is.

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So faint ones go down here

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and bright ones go up here.

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So now all we need is to put some stars on our board

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and, in fact, we've got some in our pocket.

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And the first one that we can put on is the most familiar star - the sun.

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And it turns out the sun goes bang in the middle of our diagram here.

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Surface temperature of about 6,000 Kelvin,

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so halfway along here and then, medium brightness as well.

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We can also do the brightest star in the sky and that's Sirius.

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And Sirius is a bit hotter and a bit brighter than our sun,

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so that goes up here.

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The nearest star system to our own is made up of Alpha Centauri.

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A bit hotter, a bit brighter than the sun. That has a companion,

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Alpha Centauri B, which is a bit fainter.

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Put it down there. And then, the nearest star to the sun, Proxima,

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red, much smaller, much fainter, so that goes down there.

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Now, I want to extend it up here a little bit,

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so I'm going to put on Spica, which is a staggering 12,000 times

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as bright as our sun, but because it's over 200 light-years away,

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it's a little bit fainter, how we see it,

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but it is bright in reality and it goes up here.

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And lots of our familiar bright stars in the night sky go here,

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so Vega sits about there as well.

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And then, if we add a few more stars,

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we begin to see that they fill in the gaps.

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And actually, what's really clear is that all the stars lie along

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one line in our diagram and that tells us something really important.

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They're all fusing hydrogen to helium in their cores.

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That's what's powering them.

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It's what we astronomers call the main sequence.

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But not all stars sit here.

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There are hot bright stars called blue giants, like Deneb,

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and then there are the red giants, like Arcturus,

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which our sun will become in its old age.

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These fuse helium at their core

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causing them to swell to enormous proportions.

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It's hard to get your head round the sizes of the stars,

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but luckily, I've got an onion and I want you to imagine

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that this onion is the size of the sun as it is today.

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But the sun won't stay that size forever.

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When it turns into a red giant 4,500 million years from now,

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it will swell up from the size of the onion

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to be the size of the dome and that will encompass the Earth's orbit.

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And if that's not impressive enough, Betelgeuse,

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one of the biggest of the stars,

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so large - ten times larger in fact than Jupiter's orbit -

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would fit inside it.

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Stars don't collapse because of pressure from the core,

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pushing up against gravity.

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As the star grows old, these two forces strain against each other,

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rather like a tug-of-war.

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JON CULSHAW, LIKE A BBC SPORTS COMMENTATOR: 'And you join us here

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'for our stellar tug-of-war! We have two teams, Team Gravity,

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'an ever present force, trying to pull everything inwards!

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'And then, there is Team Star, which has energy and pressure on its side,

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'resisting the pull of gravity. Team Star is nuclear!

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'They are burning hydrogen and you can feel the heat!

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'Team Gravity, though, they never give up.

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'They are a force to be reckoned with!'

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We stand a better chance of survival if we work together.

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'Team Star, quite magnificent, producing just enough heat and light

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'to balance gravity! Absolute stalemate here!

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TEAMS GRUNT

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'But Team Star running out of steam! The hydrogen has all but gone here!

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'They are beginning to collapse!

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'Team Gravity sensing success here, surely!'

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LOUD GRUNTING

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'But, but, hang on a minute, deep in the core, things are heating up here!

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'Team Star are fighting right back. Suddenly, they're right back in it,

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'burning helium, a surge in the energy! Team Star is now a red giant

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'and the crowd love it!' CHEERING

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'Gravity on the run here, you would have to say, Derek!

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'But hold on a minute! Team Star has spent their fuel.

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'They have burned up. They're all gone. Nothing left.

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'And Gravity continues pulling in and the star collapses.

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'It becomes a quite spectacular nebula

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'with a tiny white dwarf at its heart.

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'Gravity wins the day! Remarkable.'

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Eventually, the outer layers of the sun will be expelled into space,

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becoming a planetary nebula.

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The core, called a white dwarf,

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will be all that remains of our once mighty star.

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We see lots of planetary nebulae in our night sky.

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They are beautiful and ephemeral. The death of a star caught in time.

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The most massive stars,

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like hot blue Deneb, don't die quietly.

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Once their fuel is consumed,

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the star collapses

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and the result is one of the most violent explosions in the universe.

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We call it a supernova.

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These cataclysmic stellar deaths can outshine an entire galaxy,

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and, in 1987, we were treated to one in a galaxy on our cosmic doorstep

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in the nearby Large Magellanic Cloud.

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The object, called Supernova 1987A,

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has been studied in great detail ever since,

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and astronomers have watched the glowing rings of material

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spreading out into the cosmos.

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You can see the remnants of supernovae in the night sky

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with even a moderately-sized telescope.

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Nearly 1,000 years ago,

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a blue giant star exploded in the constellation of Taurus.

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And we see it today as the Crab Nebula.

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The astronomers at Herstmonceux studied these objects and many more.

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And Jon's been finding out what it was like to work here.

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Life for an astronomer at Herstmonceux was busy,

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observing by night and day.

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With all the telescopes working at night-time in the Sussex countryside,

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it must have been an active and exciting place to be.

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But there was time for some R and R,

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with some interesting accommodation next door.

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Not every astronomer gets the chance to sleep in a 15th-century castle.

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The observatories were purpose built to fit in with the castle setting.

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A flint knapper was brought out of retirement to finish the outsides

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and the copper domes finished in verdigris.

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But unfortunately, all the effort building this magnificent facility

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couldn't improve the British weather. Almost as soon as it was finished,

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plans were afoot to move to the Canary Islands,

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where the seeing was better and, by 1990, the observatory closed.

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Dr Graham Appleby was a solar observer here.

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So, Graham, you worked here from 1970 to 1990.

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Really the heyday of Herstmonceux as a Royal Observatory.

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What are some of your most memorable observations

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and studies that would have happened during that time?

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I began observing the sun.

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My first job was looking

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at the sunspots through hydrogen-alpha filters

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and flares. It was a very active time in the sun,

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so it was amazing to see, from the ground, these sunspots erupting.

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Then I got involved in observing the moon,

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the passage of the moon across in front of stars,

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so looking at that was very exciting as well.

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And as observatories go, it's a very beautiful place.

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-Yes.

-Wonderfully landscaped and so on.

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But some of the astronomers, in the early days that this was crafted,

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were a little sceptical about that.

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-You don't need a pond when you're studying the stars at night.

-Exactly.

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Imagine this completely dark, some little lights may be glowing,

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but you come out of this dome up here,

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which I worked in quite a lot, Dome D, it has a 10 centimetre refractor.

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We used to use it to observe minor planets.

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And you can imagine coming out of the steps there and,

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if you make a wrong turn, you're in the pond.

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So it's not the best design.

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It looks great, but it's not the best design for a dark observatory.

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But now, Herstmonceux is this wonderful visitor centre

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and scientific centre and a great place for astronomy outreach.

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Lots of people being inspired as they visit here,

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so sort of a new kind of heyday, isn't it now?

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Yes, to see these older telescopes now being used for education

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is a perfect link, actually, is a perfect result.

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Patrick himself was a great, great fan of this place.

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So I'm sure he'd be delighted to see it

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as this great centre of outreach for astronomy,

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sparking new interests in astronomy all the time as people visit.

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The observatory here shone brightly, but all too briefly.

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'Chris North and I are going to see

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'how they used to study the light from stars.'

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Here, we've got the largest telescope on the site -

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the 36 inch yapp reflector.

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It's built in the 1930s, moved here in the '50s,

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and it's quite a remarkable feat of engineering, isn't it?

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It is wonderfully imposing to see it, really arresting as you walk in.

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This, of course, adapted for spectroscopy,

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so it can decode and specifically study starlight and really tell us

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about the signature of stars and show us their uniqueness.

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So you can do this with a prism, split the sun's light, or you can

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-even create the same effect using the back of a CD.

-Exactly.

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But to see the light from other stars that are fainter than the sun,

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you've actually got to use a telescope like this to

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collect enough light, because they are so much fainter than the sun.

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When we do that, we see something quite remarkable in the spectrum.

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-I imagine this would collect rather a lot of light.

-Yes.

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-And give us the chance that we could study it over here.

-Indeed.

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Ah! There was one of these on Mr Dwyer's laboratory wall at school.

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They're very decorative, but what do they tell us?

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This is the sun, right?

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So this is a representation of the light from the sun,

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split out into its rainbow, its spectrum of colours.

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And it goes from red through purple, as you might expect,

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but there are specific colours that appear much darker

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and that's because those very specific colours, like this one,

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absorbed by specific types of elements in the sun's atmosphere,

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so this one, in the red end of the spectrum,

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is absorbed by hydrogen in the sun's atmosphere

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and there are other elements as well, so hydrogen absorbs

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at this wavelength and other wavelengths as well. But we can

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also see that there's small amounts of calcium in the sun's atmosphere

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and the small amounts of iron in the sun's atmosphere.

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We can start to get a spectral fingerprint

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-of what the sun is made of.

-And the chart above.

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Now, this is from a blue giant star.

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Some of the lines are in a similar position,

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but there's a lot that's different about it.

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What differences are we seeing there?

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So the first thing about the blue giant star is that

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it's very bright in the blue, but it's very dim in the red

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and that's because the star is much hotter.

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The fact that the star's a lot hotter also means that

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some of those elements in the atmosphere

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are completely stripped of their electrons already.

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Now that means they can't absorb any light,

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so we don't see absorption lines, as these are called,

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from iron and from calcium and that kind of thing.

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We mainly just see hydrogen in the atmospheres of those stars.

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So we had the diagram - the HertzsprungRussell diagram

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that Chris and Lucie were showing us earlier -

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and we had the sun right in the middle,

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and the hot blue stars up on the top left,

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then, down the bottom right, we had the cold red stars.

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And this is one of those cooler red stars.

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We can see that it's very bright in the red

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and it's much fainter in the blue. That tells us it's much cooler.

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But also, the spectrum's a lot busier.

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There's an awful lot more lines in there.

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And whereas the atmospheres of these stars, these warmer stars,

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are dominated just by atoms in their atmospheres,

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in cooler stars, you can have molecules. You can have chemistry.

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This is atoms joined together. Molecules absorb light

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at many, many more colours than just the pure atoms do.

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And if you go to even colder temperatures too,

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things get even more complex,

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because not only do you get redder and redder

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until you're almost invisible to the light we see with our eyes,

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not only do you have molecules and chemistry in the atmosphere,

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you get something you really wouldn't expect. You get weather.

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And you certainly don't associate that taking place on a star

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and this takes us to that strange world of the brown dwarf.

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A very curious object, sort of like a duck-billed platypus, in a way.

0:17:570:18:02

Hard to classify exactly what they are.

0:18:020:18:04

-LUCIE:

-Brown dwarves are a new addition to our star chart

0:18:070:18:11

and are the coolest and dimmest of stars.

0:18:110:18:15

Hertzsprung and Russell could only have dreamed

0:18:150:18:18

of these strange beasts.

0:18:180:18:20

Part of the difficulty has been seeing them,

0:18:220:18:25

because they don't shine brightly like our star.

0:18:250:18:29

To find them, we need infrared telescopes,

0:18:290:18:31

which can pick out cool objects.

0:18:310:18:34

'Ben Burningham from the University of Hertfordshire

0:18:360:18:39

'is a brown dwarf hunter.

0:18:390:18:41

'He uses space telescopes like Spitzer and WISE

0:18:430:18:47

'to look for these elusive beasts of the star family,

0:18:470:18:51

'which lurk in the cold dark parts of space.'

0:18:510:18:54

They're very peculiar objects.

0:18:540:18:56

I'm sort of struggling to conceptualise where they sit.

0:18:560:18:59

They seem a bit like the missing link in between stars and planets somehow.

0:18:590:19:02

They certainly are the missing link between stars and planets.

0:19:020:19:05

The warmer ones look a lot like stars.

0:19:050:19:07

They show a lot of the behaviour we see stars having,

0:19:070:19:09

but then, the lowest mass ones look like planets.

0:19:090:19:12

They have weather, for example. You see dust cloud weather and things

0:19:120:19:15

at sort of about 1,000 degrees centigrade.

0:19:150:19:17

So you go from studying the kind of plasma physics

0:19:170:19:20

of charged particles in a stellar atmosphere

0:19:200:19:23

with protons and electrons flying around

0:19:230:19:25

to atmospheric chemistry, where you're using

0:19:250:19:27

the language of planetary science rather than stellar physics.

0:19:270:19:31

And what kind of temperatures are we talking about here?

0:19:310:19:33

Well, they range from the temperatures of the coolest stars -

0:19:330:19:36

at about 1,700 degrees centigrade - to much, much lower temperatures.

0:19:360:19:40

In fact, a few years ago, I was very pleased when I pushed the record

0:19:400:19:43

along with a team of astronomers at Hertfordshire to down

0:19:430:19:46

to about 500 Kelvin, which we thought was about good for oven chips.

0:19:460:19:49

Yeah, congratulations on that record.

0:19:490:19:51

Well, yeah, it's been taken pretty comprehensively now.

0:19:510:19:54

The WISE Mission, a satellite from NASA,

0:19:540:19:56

has managed to push the temperature limit down to about 300 Kelvin,

0:19:560:19:59

which is room temperature.

0:19:590:20:01

-Hang on, room temperature?

-Yeah.

-Like this temperature?

0:20:010:20:04

A bit warmer than this temperature. CHRIS LAUGHS

0:20:040:20:06

But, um, but yeah, about 300 Kelvin, 20 degrees centigrade.

0:20:060:20:09

So how do you say whether something is a star

0:20:090:20:13

-or whether something is a planet?

-Well, that's tricky.

0:20:130:20:16

So people tend to take a kind of gut feeling approach.

0:20:160:20:18

Does the thing taste like a planet, does it smell like a planet?

0:20:180:20:21

The definition, officially, is when something is low enough mass

0:20:210:20:25

that it doesn't burn something called deuterium in the core

0:20:250:20:27

-when it's very young.

-Like heavy hydrogen?

-Yeah.

0:20:270:20:30

Whether it burns that in the core when it's very young,

0:20:300:20:32

then we call it a planet if it's orbiting a star.

0:20:320:20:34

Um, they have, er, atmospheres that are predominantly

0:20:340:20:37

composed of hydrogen, but the molecules we see in the atmosphere,

0:20:370:20:41

so things like water, methane and, at the coldest temperatures, ammonia.

0:20:410:20:44

And it's probable that, when we get to these temperatures,

0:20:440:20:47

we'll start to see water clouds in their atmospheres.

0:20:470:20:50

Where are the nearest brown dwarfs? How close are they to us?

0:20:500:20:53

Well, they're very close.

0:20:530:20:55

In fact, just recently, an American astronomer, working on his own

0:20:550:20:58

looking through the WISE dataset,

0:20:580:21:00

found a brown dwarf within six light years of Earth,

0:21:000:21:03

which makes it one of the closest object to the sun.

0:21:030:21:06

-What, the third closest stellar system?

-Yeah.

-Something like that.

0:21:060:21:09

-Yeah.

-And we had no idea it was there?

-No idea at all.

0:21:090:21:11

It was hiding against the crowded background of the galactic plain.

0:21:110:21:14

Lots of people have been looking, but it's a very hard job

0:21:140:21:17

to find these things and a lot of people were kicking themselves.

0:21:170:21:20

It seems slightly careless to have missed a starlike object that close.

0:21:200:21:24

Careless is a strong word. LAUGHTER

0:21:240:21:26

Sorry, I don't mean to be rude.

0:21:260:21:28

-I guess it shows how little we know about the galaxy.

-Very hard, yeah.

0:21:280:21:31

-So is that the closest one?

-That's very hard to say. Um, probably not.

0:21:310:21:36

I would say, if we're still finding things at six light years,

0:21:360:21:39

there may be things even closer. Um, it would be pretty ambitious

0:21:390:21:42

to say that's definitely the closest one.

0:21:420:21:45

'The other odd thing about these stars

0:21:450:21:48

'is that they don't seem to die.'

0:21:480:21:50

They just get colder and colder.

0:21:500:21:53

They are immortal stars

0:21:530:21:55

ending their lives in the lonely emptiness of space.

0:21:550:21:59

We're hoping to see some brighter stars tonight.

0:22:010:22:04

Wealden Astronomical Society is resident here

0:22:040:22:07

and they've joined us to keep us company.

0:22:070:22:10

Paul is talking to John Pilbeam

0:22:110:22:13

about some objects we hope to see later.

0:22:130:22:17

What sort of area

0:22:170:22:19

of amateur astronomy is your particular thing? What grabs you?

0:22:190:22:22

Star clusters, and double stars. I love double stars, yeah.

0:22:220:22:25

I don't often hear people say that, actually.

0:22:250:22:28

-Like the really geeky aspects...

-I know.

-..of amateur astronomy.

0:22:280:22:31

-What's your favourite double star?

-Albireo.

0:22:310:22:33

-I think we've got to say that.

-I have to.

-It's quite nice.

0:22:330:22:36

Andromeda, I think, has a nice...

0:22:360:22:38

is second one to that with the coloured stars,

0:22:380:22:40

-but Albireo is the favourite.

-The lovely orange and blue.

0:22:400:22:43

-It really is.

-It is the blue that catches you.

0:22:430:22:46

Gary Palmer likes studying my favourite star - our sun.

0:22:460:22:51

Pete's finding out why he enjoys solar observing so much.

0:22:510:22:55

It's the perfect thing for the public,

0:22:550:22:57

-cos it's during the day.

-That's right, yeah. It's also nicer for me,

0:22:570:23:01

-cos I keep warmer, so, um...

-LAUGHTER

0:23:010:23:04

-No, I've seen some of your pictures and they are spectacular.

-Thank you.

0:23:040:23:08

And you specialise particularly

0:23:080:23:10

-in what's known as hydrogen alpha imaging...

-Yeah.

0:23:100:23:13

..which is taking pictures of the sun's chromosphere,

0:23:130:23:15

the prominences and whatever going on.

0:23:150:23:17

-You've been looking at the sun today, haven't you?

-Yeah.

0:23:170:23:20

It's been really interesting today. There's some nice detail on there.

0:23:200:23:23

I have been fighting with the wind and clouds a little.

0:23:230:23:25

-A bit windy, yeah.

-Um, but did manage to get some nice images.

0:23:250:23:29

-Right, anything particularly stand out?

-Yeah, there was a nice flare

0:23:290:23:33

that came off the edge of the sun earlier on,

0:23:330:23:35

-and gradually developed into a nice loop prominence.

-Oh, really?

0:23:350:23:38

-They're fantastic!

-It was really nice, yeah, lovely to watch.

0:23:380:23:41

And there was a lovely large prominence coming off.

0:23:410:23:45

That had some fantastic shapes in there.

0:23:450:23:48

Um, and also, a lot of sunspots,

0:23:480:23:50

so it seems like there's a lot of activity starting again.

0:23:500:23:53

-Do you think the sun's starting to wake up a bit?

-I think so.

0:23:530:23:56

-About time.

-Yeah, it's very, very late.

0:23:560:23:59

It's a little bit like our summer this year.

0:23:590:24:01

JON: So, Paul and Pete, what of the stars in the June sky at the moment?

0:24:070:24:12

We're waiting for the clouds to co-operate. It looks like

0:24:120:24:14

-more are blowing in.

-It doesn't look promising.

-Not at the moment,

0:24:140:24:17

-but at least June is the time for the noctilucent clouds.

-Ah, yes.

0:24:170:24:21

-We like those.

-We do.

-Pete's obsessed with them.

0:24:210:24:24

They're great, because the nights in June are really, really short,

0:24:240:24:27

so these are things that are easy to see, if they're there.

0:24:270:24:30

They glow with an electric blue light,

0:24:300:24:33

like a network of clouds in the night sky.

0:24:330:24:35

They're really high altitude clouds, they're picking up

0:24:350:24:38

the light reflecting off them from the sun, which is below the horizon.

0:24:380:24:41

-They're something which are unique to the summertime.

-They do have that

0:24:410:24:45

-wonderful ethereal glow to them.

-They do and the interesting thing is

0:24:450:24:48

how subtly they can change over the course of 10-15 minutes.

0:24:480:24:51

They really are dynamic objects. Lovely things.

0:24:510:24:54

And June also the time of the moon's perigee,

0:24:540:24:56

-the super moon, as they call it.

-That's right. This is one

0:24:560:24:59

of those events that normally gets people very excited, doesn't it?

0:24:590:25:03

The moon is going to be

0:25:030:25:05

a tiny fraction of a bit larger in the sky.

0:25:050:25:07

It's actually 23rd of June and it's because the moon

0:25:070:25:10

-is at the closest point in its orbit.

-Perigee.

0:25:100:25:12

And that coincides with it being full moon this time.

0:25:120:25:15

It has the name super moon. That's actually an astrological term.

0:25:150:25:18

-We won't have such things here!

-Astrologers brought it in.

0:25:180:25:21

-Don't mention them again!

-Let's say perigee moon.

0:25:210:25:23

Well, spectacular as that moon will be,

0:25:230:25:25

hopefully it won't wash the stars out too much.

0:25:250:25:27

So which particular ones should we be looking out for in June?

0:25:270:25:30

Well, the lives and deaths of stars, something we've looked at on the programme.

0:25:300:25:34

We've got those in the summer night sky,

0:25:340:25:36

so let's start with star clusters and the wild duck cluster,

0:25:360:25:40

-M11, is a good one, isn't it?

-Lovely, actually.

0:25:400:25:42

That's at the bottom of Aquila the eagle.

0:25:420:25:44

A little curve of stars points to it.

0:25:440:25:46

When you look at it through a telescope...

0:25:460:25:49

Even a small telescope will show a beautiful smattering of stars there.

0:25:490:25:52

They're supposed to be arranged in a sort of V shape,

0:25:520:25:54

which is supposed to look like a cluster of wild ducks

0:25:540:25:57

-flying across the sky.

-It does look a bit like what it's supposed to.

0:25:570:26:00

-One of those rare objects...

-You've got a good imagination,

0:26:000:26:03

because I've never seen that.

0:26:030:26:04

-LAUGHTER

-So viewers' imagination!

0:26:040:26:07

But we also have a nice globular cluster.

0:26:070:26:09

It's low down in the constellation of Sagittarius.

0:26:090:26:12

-This is in your teapot asterism, isn't it?

-That's right.

0:26:120:26:14

It's at the heart of Sagittarius,

0:26:140:26:16

which sort of marks the region where the centre of the Milky Way is.

0:26:160:26:20

-It looks exactly like a teapot.

-Not exactly!

-Oh, it does!

0:26:200:26:23

It's exactly like a teapot. But if you imagine where steam would

0:26:230:26:26

rise out of the spout of the teapot, loads of stuff around there.

0:26:260:26:29

You've got the Lagoon Nebula, which is one of only two

0:26:290:26:32

areas of nebulosity you can see with the naked eye in the night sky.

0:26:320:26:36

You've got the Trifid Nebula, which is a beautiful thing

0:26:360:26:38

to look at through a telescope. Three dark lanes cuts it into three.

0:26:380:26:41

And then, you've also got M22, which is the brightest globular cluster

0:26:410:26:45

which can be seen from the northern hemisphere,

0:26:450:26:48

and you've got M25, which is another beautiful cluster.

0:26:480:26:51

-A deep sky treasure trove.

-It is, absolutely.

0:26:510:26:54

It's a pity it's so low down, that's the only unfortunate thing about it.

0:26:540:26:57

Well, at the other end of the spectrum, we have star death,

0:26:570:27:00

and this is represented by a fine selection of planetary nebula.

0:27:000:27:03

In particular, I think, the Ring Nebula in Lyra

0:27:030:27:06

is a really fine example of this.

0:27:060:27:07

I think you should try this in London, Jon.

0:27:070:27:09

I think that telescope of yours would pick it up.

0:27:090:27:11

And if you've got a large enough power, and conditions are good,

0:27:110:27:14

you see a sort of ghostly smoke ring in the sky.

0:27:140:27:18

Well, there's a fine thing to look out for. June full of promise.

0:27:180:27:21

-And, hopefully, some clear skies.

-Yes!

0:27:210:27:24

Many fine objects to observe in June, so long as the weather co-operates

0:27:270:27:31

and you can use Pete's sky charts to help locate them,

0:27:310:27:35

including the teapot and its steam, if you like.

0:27:350:27:37

Just go to our website...

0:27:370:27:39

We have had no luck with the weather and it's even starting to rain.

0:27:460:27:51

Wealden Astronomical Society are packing up.

0:27:510:27:54

Let's hope, next time, we come and enjoy Herstmonceux's dark skies.

0:27:540:28:00

In the meantime, it's just the ducks and us that are left behind

0:28:000:28:05

to enjoy this beautiful and atmospheric observatory.

0:28:050:28:08

We've had a great time here at Herstmonceux.

0:28:110:28:13

It's been wonderful to see these lovely old telescopes.

0:28:130:28:17

And when we come back next month, we'll be celebrating

0:28:170:28:19

the summer solstice by launching our Moore Moon Marathon.

0:28:190:28:22

We've selected some easy-to-find features on the moon

0:28:220:28:25

for you to tick off during those warm summer nights.

0:28:250:28:28

And so, until next month...

0:28:280:28:29

ALL: Good night.

0:28:290:28:31

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