Pressemeddelelse
En hob med en hemmelighed
5. september 2012
Et nyt billede fra ESOs La Silla-observatorium i Chile viser den spektakulære kuglehob Messier 4. Denne kugle af titusinder af ældgamle stjerner er en af de nærmeste og mest studerede kuglehobe, og nylige undersøgelser har vist, at en af dens stjerner har mærkelige og uventede egenskaber. Den kender tilsyneladende hemmeligheden bag evig ungdom.
Omkring Mælkevejen kredser mere end 150 kuglehobe, der kan dateres tilbage til universets fjerne fortid (eso1141). En af de tætteste på Jorden er hoben Messier 4 (også kendt som NGC 6121) i stjernebilledet Scorpius (Skorpionen). Dette klare objekt kan let ses i en håndkikkert tæt på den klare røde stjerne Antares, og med et lille amatørteleskop kan nogle af dens stjerner ses.
Dette nye billede af hoben fra Wide Field Imager (WFI) på MPG/ESO 2,2 meter teleskopet på ESOs La Silla-observatorium afslører mange flere af hobens titusinder af stjerner og viser hoben mod Mælkevejens rige baggrund.
Astronomer har også studeret mange af hobens stjerner individuelt med instrumenter på ESOs Very Large Telescope. Ved at brede lyset fra stjernerne ud i dets forskellige farver, kan de bestemme stjernernes kemiske sammensætning og deres aldre.
Nye resultater for stjernerne i Messier 4 har overrasket forskerne. Stjernerne i kuglehobe er gamle og derfor forventes de ikke at være rige på tungere grundstoffer [1]. Dette er hvad der er fundet, men en af stjernerne i en nylig kortlægning viser sig at have meget mere af det sjældne lette grundstof litium end forventet. Kilden til dette litium er mystisk. Normalt ødelægges dette grundstof gradvist over milliarder af år af en stjernes liv, men denne ene stjerne blandt tusinder ser ud til at kende hemmeligheden bag evig ungdom. Den har enten på en eller anden måde formået at bevare sit oprindelige litium, eller har fundet en måde til at berige sig selv med frisklavet litium.
Dette WFI-billede viser et vidvinkelbillede af hoben og dens righoldige omgivelser. Et supplerende og meget detaljeret billede af netop dette centrale område fra det kredsende NASA/ESA Rumteleskop Hubble blev også udgivet i denne uge som en del af Hubbles ugens billede-serie.
Noter
[1] De fleste af de kemiske grundstoffer, der er tungere end helium, er skabt i stjerner og spredt ud i det interstellare rum ved slutningen af deres liv. Dette berigede materiale danner derefter byggemateriale for kommende generationer af stjerner. Som et resultat har gamle stjerner, som dem i kuglehobe, der er dannet før en betydelig berigelse fandt sted, et lavere indhold af de tungere grundstoffer i forhold til stjerner som Solen, der er dannet senere.
Mere information
I år 2012 er der 50-års jubilæum for grundlæggelsen af det Europæiske Syd Observatorium (ESO). ESO er den mest fremtrædende internationale astronomi-organisation i Europa og verdens mest produktive astronomiske observatorium. ESO har i dag følgende 15 medlemslande: Belgien, Brasilien, Danmark, Finland, Frankrig, Holland, Italien, Portugal, Schweiz og Storbritannien, Spanien, Sverige, Tjekkiet, Tyskland og Østrig. ESOs aktiviteter er fokuseret på design, konstruktion og drift af jordbaserede observationsfaciliteter for at muliggøre vigtige videnskabelige opdagelser inden for astronomi. ESO spiller også en ledende rolle for at fremme og organisere samarbejdet inden for astronomisk forskning. I Chile driver ESO tre unikke observatorier i verdensklasse: La Silla, Paranal og Chajnantor. På Paranal driver ESO Very Large Telescope (VLT), der er verdens mest avancerede astronomiske observatorium til observationer i synligt lys samt to kortlægningsteleskoper. VISTA arbejder i infrarødt lys og er verdens største kortlægningsteleskop, mens VLT Survey Telescope (VST) er det største teleskop, der udelukkende er bygget til at kortlægge himlen i synligt lys. ESO er den europæiske partner i et revolutionerede astronomisk teleskop kaldet ALMA, det største igangværende astronomiske projekt. ESO planlægger i øjeblikket et 40 meter optisk/nær-infrarødt teleskop kaldet European Extremely Large Telescope (E-ELT), der vil blive ”verdens største øje mod himlen”.
Links
- Videnskabelig artikel om den overraskende litium-rige stjerne i Messier 4 (Monaco et al.)
- Billeder af VLT
- Billeder af MPG/ESO 2,2 meter teleskopet
- Andre billeder taget med MPG/ESO 2,2 meter teleskopet
- Billeder af La Silla
Kontakter
Richard Hook
ESO, La Silla, Paranal, E-ELT & Survey Telescopes Press Officer
Garching bei München, Germany
Tel: +49 89 3200 6655
Mobil: +49 151 1537 3591
E-mail: rhook@eso.org
Ole J. Knudsen (Pressekontakt Danmark)
ESOs formidlingsnetværk
og Aarhus Space Centre, Aarhus Universitet
Aarhus, Danmark
Tel: +45 8715 5597
E-mail: eson-denmark@eso.org
Om pressemeddelelsen
| Pressemeddelelse nr.: | eso1235da |
| Navn: | M 4, Messier 4, NGC 6121 |
| Type: | Milky Way : Star : Grouping : Cluster : Globular |
| Facility: | MPG/ESO 2.2-metre telescope |
| Instruments: | FLAMES |
| Science data: | 2012A&A...539A.157M |
Billeder
tekst kun tilgængelig på engelsk
Videoer
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.
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.
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.
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.
Matomo cookies settings:
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.