Meddelelse

NGTS finder sjælden gaskæmpe ved M-dværg

31. oktober 2017

Den tredje gaskæmpe - en hot Jupiter -  i kredsløb om en M-dværgstjerne[1] er fundet med Next Generation Transit Survey (NGTS) instrumentet på ESOs Paranal Observatory i det nordlige Chile. Stjernen har fået navnet NGTS-1 og planeten tilsvarende NGTS-1b. De to første varme gaskæmper var Kepler-45b og HATS-6b. NGTS-1b er den største og tungeste af de tre. Den har en radius på 130% og en masse på 80% af Jupiter i vores eget Solsystem. Danskbaseret exoplanetjæger er også begejstret.

NGTS består af et anlæg med 12 stk 20-centimeterteleskoper, som ser efter de små dyk i en stjernes lysstyrke, som kommer når en planet i kredsløb om stjernen passerer ind foran den (- en transit, svarende til en solformørkelse, men meget længere væk), og blokerer for noget af dens lys. Da først NGTS-1b var fundet, blev dens eksistens bekræftet med observationer fra ESOs La Sillaobservatorium: fotometriske observationer med instrumentet EulerCam på det schweiziske 1,2-meter Leonhard Euler Telescope og spektroskopiske observationer med instrumentet HARPS på ESOs 3,6-meter teleskop.

Små planeter er forholdsvis almindelige ved M-dværgstjerner, men det ser ud til at kæmper som NGTS-1b er sjældnere omkring denne type stjerner end de er omkring stjerner, som mere ligner Solen. Det er fint i tråd med de nuværende teorier for planetdannelse, men der er brug for flere observationer af M-dværge for at astronomerne kan få mere præcise tal. Anlægget NGTS er specielt opbygget for at få bedre data om planeter omkring M-dværgstjernerne, og da den type stjerner udgør omkring 75% af alle stjernerne i Mælkevejen, er studiet af dem vigtig for forståelsen af planeterne i hele galaksen.

Fremtiden lover godt for dette exoplanetsystem. Den vil kunne studeres i større deltalje af instrumenterne ombord på NASA/ESA/CSA James Webb Space Telescope (JWST), som nu planlægges opsendt i 2019.

Lektor Simon Albrecht fra Stellar Astrophysics Centre på Aarhus Universitet studerer også de exoplaneter, som kredser om rødfarvede stjerner. Han har ikke været direkte involveret i dette forskningsresultat, men er begejstret for den nyopdagede gasplanet. "Det er ganske usædvanligt at se denne kombination af exoplanet og M-dværgstjerne, og vi kan helt sikkert lære mere om udviklingen i planetsystemer af dette her. NGTS vil i fremtiden være et fremragende værktøj til også at kunne følge op på de opdagelser af exoplaneter omkring klare stjerner, som den kommende satellit TESS vil levere fra næste år."

Note

[1] En M-dværg er en lille, svagtlysende stjerne, som vejer et sted imellem 8 og 50% af Solen, og som har en overfladetemperatur på mindre end 3700°C. 50 ud af de 60 nærmeste stjerner omkring Solen menes at være M-dværge, men ikke en eneste af dem er klar nok eller tæt nok på os til at vi kan se den fra Jorden med det blotte øje.

Flere oplysninger

Opdagelsen bliver offentliggjort i en artikel med titlen “NGTS-1b: A hot Jupiter transiting an M-dwarf”, af D. Bayliss et al., i tidsskriftet Monthly Notices of the Royal Astronomical Society.

The team is composed of: D. Bayliss (Université de Genève, Schweiz), E. Gillen (University of Cambridge, United Kingdom), P. Eigmüller (DLR, Tyskland), J. McCormac (University of Warwick, United Kingdom), R. Alexander (University of Leicester, United Kingdom), D. Armstrong (University of Warwick, United Kingdom), R. Booth (Queen's University Belfast, United Kingdom), F. Bouchy (Université de Genève, Schweiz), M. Burleigh, J. Cabrera (DLR, Tyskland), S. Casewell, A. Chaushev (University of Leicester, United Kingdom), B. Chazelas, S. Csizmadia, A. Erikson, F. Faedi (University of Warwick, United Kingdom), E. Foxwell (University of Warwick, United Kingdom), B. Gaensicke (University of Warwick, United Kingdom), M. Goad (University of Leicester, United Kingdom), A. Grange, M. Guenther (University of Cambridge, United Kingdom), S. Hodgkin (University of Cambridge, United Kingdom), J. Jackman, J. Jenkins (Universidad de Chile, Chile), G. Lambert (University of Cambridge), T. Louden (University of Warwick, United Kingdom), L. Metrailler (Université de Genève, Schweiz), M. Moyano (Universidad Católica del Norte, Chile), D. Pollacco (University of Warwick, United Kingdom), K. Poppenhaeger, (Queen's University Belfast, United Kingdom; Harvard-Smithsonian Center for Astrophysics, USA), D. Queloz (Université de Genève, Schweiz), R. Raddi (University of Warwick, United Kingdom), H. Rauer (DLR, Tyskland), L. Raynard (University of Leicester, United Kingdom), A. Smith, M. Soto (Universidad de Chile, Chile), A. Thompson (Queen’s University Belfast, United Kingdom), R. Titz-Weider (DLR, Tyskland), S. Udry (Université de Genève, Schweiz), S. Walker (University of Warwick, United Kingdom), C. Watson (Queen's University Belfast, United Kingdom), R. West (University of Warwick, United Kingdom) and P.J. Wheatley (University of Warwick, United Kingdom).

Links

Kontakter

Ole J. Knudsen

ESON-Danmark

Stellar Astrophysics Centre, Aarhus Universitet

telefon 8715 5597, mobil 4059 4520

e-mail: eson-denmark@eso.org

Om meddelelsen

Id:ann17076

Billeder

Artist's impression of the planet NGTS-1b
Artist's impression of the planet NGTS-1b
tekst kun tilgængelig på engelsk
Artist's impression of the planet NGTS-1b
Artist's impression of the planet NGTS-1b
tekst kun tilgængelig på engelsk

Send us your comments!
Tegn abonnement for at få nyheder fra ESO på dit eget sprog
Accelereret med CDN77
Regler og vilkår
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.