File proveniente da Wikimedia Commons. Clicca per visitare la pagina originale

File:Terzan 7 by HST.jpg

Da Wikipedia, l'enciclopedia libera.
Vai alla navigazione Vai alla ricerca

File originale(4 295 × 4 169 pixel, dimensione del file: 13,53 MB, tipo MIME: image/jpeg)

Logo di Commons
Logo di Commons
Questo file e la sua pagina di descrizione (discussione · modifica) si trovano su Wikimedia Commons (?)

Dettagli

Descrizione
English: Named after its discoverer, the French-Armenian astronomer Agop Terzan, this is the globular cluster Terzan 7 — a densely packed ball of stars bound together by gravity. It lies just over 75 000 light-years away from us on the other side of our galaxy, the Milky Way. It is a peculiar cluster, quite unlike others we observe, making it an intriguing object of study for astronomers.

Evidence shows that Terzan 7 used to belong to a small galaxy called the Sagittarius Dwarf Galaxy, a mini-galaxy discovered in 1994. This galaxy is currently colliding with, and being absorbed by, the Milky Way, which is a monster in size when compared to this tiny one. It seems that this cluster has already been kidnapped from its former home and now is part of our own galaxy.

Astronomers recently discovered that all the stars in Terzan 7 were born at around the same time, and are about eight billion years old. This is unusually young for such a cluster. The shared birthday is another uncommon property; a large number of globular clusters, both in the Milky Way and in other galaxies, seem to have at least two clearly differentiated generations of stars that were born at different times.

Some explanations suggest that there is something different about clusters that form within dwarf galaxies, giving them a different composition. Others suggest that clusters like Terzan 7 only have enough material to form one batch of stars, or that perhaps its youthfulness has prevented it from yet forming another generation.

A version of this image was entered into the Hubble's Hidden Treasures image processing competition by contestant Gilles Chapdelaine.
Data
Fonte http://www.spacetelescope.org/images/potw1406a/
Autore

NASA, ESA, and A. Sarajedini (University of Florida)

Acknowledgement: Gilles Chapdelaine

Licenza

w:it:Creative Commons
attribuzione
attribuzione
ESA/Hubble images, videos and web texts are released by the ESA under the Creative Commons Attribution 4.0 International license and may on a non-exclusive basis be reproduced without fee provided they are clearly and visibly credited. Detailed conditions are below; see the ESA copyright statement for full information. For images created by NASA or on the hubblesite.org website, or for ESA/Hubble images on the esahubble.org site before 2009, use the {{PD-Hubble}} tag.
Conditions:
  • The full image or footage credit must be presented in a clear and readable manner to all users, with the wording unaltered (for example: "ESA/Hubble"). Web texts should be credited to ESA/Hubble (except when used by media). The credit should not be hidden or disassociated from the image footage. Links should be active if the credit is online. See the usage rights Q&A section on the ESA copyright page for guidance.
  • ESA/Hubble materials may not be used to state or imply the endorsement by ESA/Hubble or any ESA/Hubble employee of a commercial product or service.
  • ESA/Hubble requests a copy of the product sent to them to be indexed in their archive.
  • If an image shows an identifiable person, using that image for commercial purposes may infringe that person's right of privacy, and separate permission should be obtained from the individual.
  • If images or visuals are changed significantly from the original work (apart from resizing, cropping), we suggest that the changes are mentioned after the credit line. For example "Original image by ESA/Hubble (M. Kornmesser), warping and recolouring by NN".

Notes:

  • Note that this general permission does not extend to the use of ESA/Hubble's logo, which shall remain protected and may not be used or reproduced without prior and individual written consent of ESA/Hubble.
  • Also note that music, scientific papers and code on the esahubble.org site are not released under this license and can not be used for non-ESA/Hubble products.
  • By reproducing ESA/Hubble material, in part or in full, the user acknowledges the terms on which such use is permitted.
w:it:Creative Commons
attribuzione
Questo file è disponibile in base alla licenza Creative Commons Attribuzione 4.0 Internazionale
Attribuzione: ESA/Hubble
Tu sei libero:
  • di condividere – di copiare, distribuire e trasmettere quest'opera
  • di modificare – di adattare l'opera
Alle seguenti condizioni:
  • attribuzione – Devi fornire i crediti appropriati, un collegamento alla licenza e indicare se sono state apportate modifiche. Puoi farlo in qualsiasi modo ragionevole, ma non in alcun modo che suggerisca che il licenziante approvi te o il tuo uso.

Didascalie

Aggiungi una brevissima spiegazione di ciò che questo file rappresenta

Elementi ritratti in questo file

raffigura

Cronologia del file

Fare clic su un gruppo data/ora per vedere il file come si presentava nel momento indicato.

Data/OraMiniaturaDimensioniUtenteCommento
attuale03:57, 11 feb 2014Miniatura della versione delle 03:57, 11 feb 20144 295 × 4 169 (13,53 MB)JmencisomUser created page with UploadWizard

La seguente pagina usa questo file:

Utilizzo globale del file

Anche i seguenti wiki usano questo file:

Metadati