Een slokje ESPRESSO

Centraal op de foto staat het grote diffractietralie. Het is het hart van de de ultra-precieze ESPRESSO spectrograaf, een exoplaneetzoeker van de nieuwste generatie. Hier ondergaat hij tests in de cleanroom van het hoofdkwartier van ESO in Garching bei München (Duitsland).

Ingenieurs bij ESO hebben onlangs de tralies uitgelijnd. Dat is een ingewikkeld proces. ESO droeg bij aan de bouw en het uitlijnen van ESPRESSO. De tralies zijn de grootste ooit bij ESO gemaakt. Met 1,2 bij 0,3 meter is de tralie net zo groot als die van de HIRES-spectrograaf van de Keck 10-meter-telescoop.

Nadat de tralie is uitgelijnd, wordt hij vastgezet in zijn houder. Alle onderdelen zijn gemaakt van Zerodur (hetzelfde materiaal dat is gebruikt voor de spiegels van de VLT). De componenten hoeven nooit meer bijgesteld te worden. De techniek van het vastzetten, is bedacht bij ESO en was al eerder een succes.

ESPRESSO wordt geïnstalleerd op het Paranal Observatory van ESO in Chile in 2016. Hij gaat het licht van alle vier de 'Unit Telescopes' van de Very Large Telescope bundelen. Zo ontstaat één grote virtuele telescoop met een diameter van 16 meter. De tralie splitst het licht op in componenten zodat het geanalyseerd kan worden. Het heeft wel wat weg van het scheiden van licht via een prisma, maar er zit een ander natuurkundig mechanisme achter.

ESPRESSO wordt de opvolger van HARPS, 's werelds belangrijkste exoplanetenjager. Astronomen kunnen, met het instrument als luizenkam, gaan zoeken naar aardachtige planeten bij sterren hier niet zo ver vandaan [1]. Het instrument heeft nog meer toepassingen. Het kan bijvoorbeeld door het licht van afgelegen quasars te ontrafelen, zoeken naar fluctuaties in natuurconstanten op verschillende momenten in de evolutie van het heelal.

Noten

[1] Een planeet die rond een ster cirkelt, zorgt ervoor dat een waarnemer op aarde een kleine, regelmatige variatie in de snelheidscomponent ziet (ook wel bekend als 'radial velocity'). Deze variatie ziet eruit als een schommeling in het spectrum van de ster. De lijnen in het spectrum schuiven heen en weer dankzij het Doppler-effect. Als de planeet van de waarnemer weg beweegt, zorgt de radial velocity voor een verschuiving naar langere golflengten (een roodverschuiving). Als de planeet naar de waarnemer toe beweegt, verschuift het naar kortere golflengten (blauwverschuiving). Deze kleine verschuivingen in het spectrum van de ster zijn op aarde te zien als verschuivingen van slechts een paar nanometer. Uit deze minieme verschuivingen kan ESPRESSO de aanwezigheid van planeten afleiden.

Meer informatie

ESPRESSO (Echelle SPectrograph for Rocky Exoplanet and Stable Spectroscopic Observations) wordt ontwikkeld door een consortium van ESO en zeven wetenschappelijke instituten:

Credit:

Over de afbeelding

Id:potw1537a
Taal:nl-be
Type:Fotografisch
Publicatiedatum:14 september 2015 10:00
Grootte:5616 x 3744 px

Over het object

Naam:ESPRESSO
Type:Unspecified : Technology : Observatory : Instrument

Image Formats

Grote JPEG
3,7 MB

Inzoomen


Wallpapers

1024x768
223,4 KB
1280x1024
330,1 KB
1600x1200
452,7 KB
1920x1200
533,0 KB
2048x1536
693,5 KB

Send us your comments!
Abonneer op ESO-nieuws in uw eigen taal
Accelerated by CDN77
Terms & Conditions
Cookie Settings and Policy

Our use of Cookies

We use cookies that are essential for accessing our websites and using our services. We also use cookies to analyse, measure and improve our websites’ performance, to enable content sharing via social media and to display media content hosted on third-party platforms.

You can manage your cookie preferences and find out more by visiting 'Cookie Settings and Policy'.

ESO Cookies Policy


The European Organisation for Astronomical Research in the Southern Hemisphere (ESO) is the pre-eminent intergovernmental science and technology organisation in astronomy. It carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities for astronomy.

This Cookies Policy is intended to provide clarity by outlining the cookies used on the ESO public websites, their functions, the options you have for controlling them, and the ways you can contact us for additional details.

What are cookies?

Cookies are small pieces of data stored on your device by websites you visit. They serve various purposes, such as remembering login credentials and preferences and enhance your browsing experience.

Categories of cookies we use

Essential cookies (always active): These cookies are strictly necessary for the proper functioning of our website. Without these cookies, the website cannot operate correctly, and certain services, such as logging in or accessing secure areas, may not be available; because they are essential for the website’s operation, they cannot be disabled.

Cookie ID/Name
Description/Purpose
Provider (1st party or 3rd party)
Browser session cookie or Stored cookie?
Duration
csrftoken
XSRF protection token. We use this cookie to protect against cross-site request forgery attacks.
1st party
Stored
1 year
user_privacy
Your privacy choices. We use this cookie to save your privacy preferences.
1st party
Stored
6 months
_grecaptcha
We use reCAPTCHA to protect our forms against spam and abuse. reCAPTCHA sets a necessary cookie when executed for the purpose of providing its risk analysis. We use www.recaptcha.net instead of www.google.com in order to avoid unnecessary cookies from Google.
3rd party
Stored
6 months

Functional Cookies: These cookies enhance your browsing experience by enabling additional features and personalization, such as remembering your preferences and settings. While not strictly necessary for the website to function, they improve usability and convenience; these cookies are only placed if you provide your consent.

Cookie ID/Name
Description/Purpose
Provider (1st party or 3rd party)
Browser session cookie or Stored cookie?
Duration
Settings
preferred_language
Language settings. We use this cookie to remember your preferred language settings.
1st party
Stored
1 year
ON | OFF
sessionid
ESO Shop. We use this cookie to store your session information on the ESO Shop. This is just an identifier which is used on the server in order to allow you to purchase items in our shop.
1st party
Stored
2 weeks
ON | OFF

Analytics cookies: These cookies collect information about how visitors interact with our website, such as which pages are visited most often and how users navigate the site. This data helps us improve website performance, optimize content, and enhance the user experience; these cookies are only placed if you provide your consent. We use the following analytics cookies.

Matomo Cookies:

This website uses Matomo (formerly Piwik), an open source software which enables the statistical analysis of website visits. Matomo uses cookies (text files) which are saved on your computer and which allow us to analyze how you use our website. The website user information generated by the cookies will only be saved on the servers of our IT Department. We use this information to analyze www.eso.org visits and to prepare reports on website activities. These data will not be disclosed to third parties.

On behalf of ESO, Matomo will use this information for the purpose of evaluating your use of the website, compiling reports on website activity and providing other services relating to website activity and internet usage.

ON | OFF

Matomo cookies settings:

Cookie ID/Name
Description/Purpose
Provider (1st party or 3rd party)
Browser session cookie or Stored cookie?
Duration
Settings
_pk_id
Stores a unique visitor ID.
1st party
Stored
13 months
_pk_ses
Session cookie temporarily stores data for the visit.
1st party
Stored
30 minutes
_pk_ref
Stores attribution information (the referrer that brought the visitor to the website).
1st party
Stored
6 months
_pk_testcookie
Temporary cookie to check if a visitor’s browser supports cookies (set in Internet Explorer only).
1st party
Stored
Temporary cookie that expires almost immediately after being set.

Additional Third-party cookies on ESO websites: some of our pages display content from external providers, e.g. YouTube.

Such third-party services are outside of ESO control and may, at any time, change their terms of service, use of cookies, etc.

YouTube: Some videos on the ESO website are embedded from ESO’s official YouTube channel. We have enabled YouTube’s privacy-enhanced mode, meaning that no cookies are set unless the user actively clicks on the video to play it. Additionally, in this mode, YouTube does not store any personally identifiable cookie data for embedded video playbacks. For more details, please refer to YouTube’s embedding videos information page.

Cookies can also be classified based on the following elements.

Regarding the domain, there are:

As for their duration, cookies can be:

How to manage cookies

Cookie settings: You can modify your cookie choices for the ESO webpages at any time by clicking on the link Cookie settings at the bottom of any page.

In your browser: If you wish to delete cookies or instruct your browser to delete or block cookies by default, please visit the help pages of your browser:

Please be aware that if you delete or decline cookies, certain functionalities of our website may be not be available and your browsing experience may be affected.

You can set most browsers to prevent any cookies being placed on your device, but you may then have to manually adjust some preferences every time you visit a site/page. And some services and functionalities may not work properly at all (e.g. profile logging-in, shop check out).

Updates to the ESO Cookies Policy

The ESO Cookies Policy may be subject to future updates, which will be made available on this page.

Additional information

For any queries related to cookies, please contact: pdprATesoDOTorg.

As ESO public webpages are managed by our Department of Communication, your questions will be dealt with the support of the said Department.