Nic:

Welcome to episode four of season two of the Meridian. Once again we are recording at Lund Observatory in Sweden and we are releasing this episode on March 2nd.

Crossing our local Meridian today we are lucky to have Dainis Dravins, a professor emeritus here who studies stellar surfaces.

This season we are also bringing you some field reporting from the Nordic Optical Telescope on La Palma. It is not easy to observe with an active volcano covering everything with ash and lava, but more about that later.

 

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The intro scene includes background music and 24 high school students saying astronomical words like “Space missions”,  "Solar wind", "The big dipper", "Galactic dynamics", "Gravitational waves", "Exoplanets", "Black holes", "Betelgeuse", "Dark energy", "Near earth asteroids", "Jupiter", "Ground based telescopes" and more.  Slowly it fades to everyone saying “The Meridian”.      

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Nic:

Hi Rebecca.

Rebecca:

Hi Nic.  

Nic:

How are you?

Rebecca:

I'm actually quite excited. How are you?

Nic:

Yeah, I'm pretty good. Why are you excited?

Rebecca:

It's actually so that ESO is turning 60 this year.

Nic:

Happy birthday...

Rebecca:

Ah, we probably shouldn't sing.

Nic:

OK.  So, ESO. So what does that stand for?

Rebecca:

It stands for the European Southern Observatory, which are a collaboration of European countries that got together and started building observatories in the southern hemisphere.

Nic:

OK, so like the telescopes in Chile.

Rebecca:

Yeah, exactly. In Chile, on Paranal and in the Chajnantor dessert. So we, for instance, have the VLT and the ELT that's being built, and ALMA telescope.

Nic:

Right, OK so whole bunch that are down there.

Rebecca:

Yeah, and all of those are part of ESO.

Nic:

Right, OK cool. So so is there anything happening with this 60th birthday that ESO's having?

Rebecca:

Yes, ESO are planning to arrange a bunch of virtual events during late summer and early autumn. Details are not quite out yet, but they promised that they will post them on eso.org. So we'll keep an eye on there.

Nic:

Cool right. Is there anything else?

Rebecca:

Uhm, well, I'm guessing that there might be a lot of celebrations in Garching which is their headquarters that they have here in Europe, in Germany.  Perhaps at their Supernova planetarium.

And also here in Lund we will be celebrating during  World Space Week. But as I said, look for details on eso.org, 'cause I think there will be celebrations all over Sweden.

Nic:

Right, and if you can't get out anywhere, is there any other options that are available to you?

Rebecca:

Yeah, they said that they would do live tours of the facilities on Facebook.

Nic:

Right cool.

Rebecca:

So the thing is that Sweden is actually one of the five founding members of ESO.

Nic:

Right, who are the others?

Rebecca:

Germany, France, Belgium and the Netherlands.

Nic:

OK, that's pretty cool.

Rebecca:

Yeah it is!  Which is how we are part of it.  And how we can collaborate, with having the telescopes there.  For instance, we have Diane from few episodes back who is a part of this 4MOST collaboration.  That's part of ESO.

Nic:

OK, so that's ESO, right? So, I sometimes hear ESA with an A. What's the difference between those?

Rebecca:

Yes, yeah exactly so ESA is the European Space Agency and they also have telescopes, but they're mostly up in space. So for instance, Gaia, that Paul talked about.

Nic:

Oh OK, cool. And didn't you apply to be an astronaut with ESA?

Rebecca:

Yes, exactly. So ESA is in a way Europe's NASA.  They have astronauts, they have satellites and space telescopes, and it's also a collaboration of European countries that's come together to do.... well, space science.

Nic:

Right OK cool.  Yeah, well they really need to work on the astronaut application programme. ‘Cause they’re filtering out the wrong people.

Rebecca:

Yea, exactly.   

In Sweden we're a part of ESA through our Swedish space agency called Rymdstyrelsen, and so that's how we're an active member if that and have Gaia for instance, that Paul talked about.

Nic:

OK so it's ESO - European Southern Observatory - and then ESA - the European Space Agency.

Rebecca:

Yes, any questions?

Nic:

Just one.  Why do we want to observe in the southern hemisphere?

Rebecca:

Sure, that's a good question, and I actually thought we could ask our guests coming into this episode, Dainis Dravins, about it. So let's invite him to the mic.

Nic:

Sure thing.

 

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Rebecca:

So welcome Dainis, I'm super happy to have you here.

Dainis:

Thanks.

Rebecca:

So could you tell us a bit about yourself 'cause you've been here at the observatory for quite some time, right?

Dainis:

Yes, and actually I started in Lund quite some time ago - by arranging to be born here.  So that's my first encounter with Lund.  

Yes, I've been here quite some time and nowadays I'm sort of working mainly on research, as a senior astronomer.  Spending most of my time in Lund but also with various interludes elsewhere.

Rebecca:

Yes, OK, and what kind of science are you doing?

Dainis:

I'm mainly working to analyse spectra of the Sun, spectra of stars, methods for precise observations, methods to make the ultimate in spectroscopy to search for other planets, to understand the fine details on stable surfaces, and to look for what are they frontiers maybe 10-20 years from now.

Rebecca:

Yeah, 'cause I've heard that you were sort of looking into methods of finding another earth. Is that even possible?

Dainis:

Yes, nothing is impossible. Things are just more or less difficult.

You may encounter now and then headlines in the media that a so-called Earth-like-planet has been found.

Well, that's not really true. Well, it's not fake news either, but it's sort of incomplete. What has been found are planets, maybe the size of the Earth, the temperature of the Earth or maybe one where the host star is something like our Sun.  But to find a real Earth-twin, an exo-Earth, that is a planet the size of the Earth moving in a little bit about one year around it's star, it's Solar-like star, in roughly a year of period and so on that has never been done and is currently not possible.

And that is the Big challenge.

Rebecca:

Right, and that's something you're looking into.

Dainis:

Yes, because the methods to find such a planet include, for example, looking at the slight wobble that a star is experiencing as the planet is pulling on it by its gravity.

But the effect is so tiny for an earth like planet so that it's been very difficult to get the precision in measurements to get it. But were there now.  We could measure it if - if the star was shining like a stabilised laser.   

But it isn't.  The light from the star is diffuse.  The spectrum of the star is broadened, it is perturbed by everything that happens on the star. The star is boiling, it's oscillating, there are star spots and so on.

So the challenge now is not to get higher measurement precision, but it's to understand how to get rid of all these extra effects so we can look at the true motion of the star, and not just what is simmering on its surface.

Rebecca:

Right, so sort of like the the planet end up in this noise that the star is producing.

Dainis:

Excactly.  And what we're trying to do just now is to see can we do this for the Sun.  We're observing the Sun.  The Sun is being observed the same way as one observes stars, and this is done with tiny telescopes that are placed in the daytime outside the domes of the big telescopes. For example, on La Palma. And then every five minutes or so there is a spectrum of the Sun recorded, and this has been going on for several years.

Now we have 10s of thousands of such, so most picture there are always all the time jittering in wavelenght. They are flickering intenseity.  And we're trying to understand what of this jittering and flickering is due to the Sun and what could possibly be due to the motion of the sun as such.

 

 

 

 

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