Pedimos desculpa pelo incómodo! Esta página ainda não está disponível na língua que escolheu, por isso apresentamo-la na versão original.
Page saved successfully
Couldn't save page :( Please try again.
PoET
The Paranal solar ESPRESSO Telescope
The hunt for other Earths is a key objective of modern day astrophysics, but faces considerable challenges. Our ability to detect and characterise exoplanets is severely impacted by astrophysical ‘noise’ originating from their host stars, which distorts observed spectra.
With that in mind, the Paranal solar ESPRESSO Telescope (PoET) was envisioned. Funded by the FIERCE project (FInding Exo-eaRths: tackling the ChallengEs of stellar activity, funded by the European Union, ERC, 101052347), and led by the Instituto de Astrofísica e Ciências do Espaço (IA), Portugal, the telescope aims to study the Sun to understand how other stars can hide their orbiting planets, advancing the search for exoplanets.
PoET, which is located at ESO’s Paranal Observatory, consists of a main telescope and a pointing telescope. The main one, with a diameter of 60 centimetres, is designed to observe small areas of the solar disc, and can make observations of stellar features on different spatial scales. The pointing telescope consists of two simple refractors, known as the ‘science’ and the ‘imaging’ telescopes, and collects light from the entire solar disc, identifying regions to be observed by the main telescope.
PoET, which is housed behind the Very Large Telescope (VLT) Interferometer Lab at the centre of the VLT platform, is linked through optical fibres to ESPRESSO, a spectrograph that normally operates as a VLT instrument. As ESPRESSO can be fed by two fibres at once, it can simultaneously capture the light emitted from stellar features and from the entire solar disc, something unprecedented on ground-based telescopes. Making observations during the day, the telescope won’t disrupt the VLT’s night-time use of ESPRESSO. PoET is operated remotely from IA's University of Porto pole, at the Centro de Astrofísica da Universidade do Porto (CAUP), Portugal.
PoET achieved first light in April 2026, and its data is available to other researchers through the ESO Science Archive Facility.
Science with PoET
PoET’s mission is to contribute to the detection and characterisation of exoplanets, by analysing the Sun to understand how the spectra of solar-type stars can mimic or disguise exoplanets’ signatures.
High-resolution spectroscopy is one of the main methods employed in the search and study of other worlds, detecting the subtle motions of a star and thus inferring the presence of a planet, complemented by transit photometry, which detects the periodic dimming of a star's light as an orbiting body passes in front of it. However, Sun-like stars have surface activity that can subtly distort the light detected by spectrographs used for exoplanet research, incorrectly hinting at an orbiting planet’s properties or disguising a exoplanet’s presence altogether. Different methods are currently used to correct this ‘noise’, but none have yet reached the required precision levels to observe other terrestrial worlds. Our incomplete knowledge of stellar physics is a key factor in the inability to solve this problem, as we cannot precisely model the effects we observe on the Sun and other stars.
The Sun is the only star for which we can resolve the stellar disc to the level of detail required, and, for that reason, it was chosen as a guide to understand the exact contribution of different regions to an overall stellar spectrum. PoET allows us to point to any region in the solar disc and inject its light, simultaneously with that coming from the entire disc, into ESPRESSO. In doing so, we can identify the different physical processes that result in stellar variations in solar-type stars, and understand, as well as possibly correct, their effects, which is fundamental to the success of exoplanet research.
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:
First-party cookies, set by the website you are currently visiting. They are stored by the same domain that you are browsing and are used to enhance your experience on that site;
Third-party cookies, set by a domain other than the one you are currently visiting.
As for their duration, cookies can be:
Browser-session cookies, which are deleted when the user closes the browser;
Stored cookies, which stay on the user's device for a predetermined period of time.
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.
