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

File:Hiding in the night sky.jpg

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

File originale(1 280 × 1 019 pixel, dimensione del file: 159 KB, 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: This striking NASA/ESA Hubble Space Telescope image captures the galaxy UGC 477, located just over 110 million light-years away in the constellation of Pisces (The Fish).

UGC 477 is a low surface brightness (LSB) galaxy. First proposed in 1976 by Mike Disney, the existence of LSB galaxies was confirmed only in 1986 with the discovery of Malin 1. LSB galaxies like UGC 477 are more diffusely distributed than galaxies such as Andromeda and the Milky Way. With surface brightnesses up to 250 times fainter than the night sky, these galaxies can be incredibly difficult to detect.

Most of the matter present in LSB galaxies is in the form of hydrogen gas, rather than stars. Unlike the bulges of normal spiral galaxies, the centres of LSB galaxies do not contain large numbers of stars. Astronomers suspect that this is because LSB galaxies are mainly found in regions devoid of other galaxies, and have therefore experienced fewer galactic interactions and mergers capable of triggering high rates of star formation.

LSB galaxies such as UGC 477 instead appear to be dominated by dark matter, making them excellent objects to study to further our understanding of this elusive substance. However, due to an underrepresentation in galactic surveys — caused by their characteristic low brightness — their importance has only been realised relatively recently.
Data
Fonte http://www.spacetelescope.org/images/potw1614a/
Autore

ESA/Hubble & NASA

Acknowledgement: Judy Schmidt (Geckzilla)

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

Valore sconosciuto senza un elemento Wikidata

Cronologia del file

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

Data/OraMiniaturaDimensioniUtenteCommento
attuale11:19, 4 apr 2016Miniatura della versione delle 11:19, 4 apr 20161 280 × 1 019 (159 KB)JmencisomUser created page with UploadWizard

Le seguenti 2 pagine usano questo file:

Utilizzo globale del file

Anche i seguenti wiki usano questo file:

Metadati