Viquipèdia

Fitxer:Pre-planetary nebula, IRAS 23166+1655.jpg

Fitxer original (1.625 × 1.625 píxels, mida del fitxer: 1,39 Mo, tipus MIME: image/jpeg)

Descripció a Commons

Resum

Descripció
English: This remarkable picture from the Advanced Camera for Surveys on the NASA/ESA Hubble Space Telescope shows one of the most perfect geometrical forms created in space. It captures the formation of an unusual pre-planetary nebula, known as IRAS 23166+1655, around the star LL Pegasi (also known as AFGL 3068) in the constellation of Pegasus (the Winged Horse).

The striking picture shows what appears to be a thin spiral pattern of astonishingly regularity winding around the star, which is itself hidden behind thick dust. The spiral pattern suggests a regular periodic origin for the nebula’s shape. The material forming the spiral is moving outwards a speed of about 50 000 km/hour and, by combining this speed with the distance between layers, astronomers calculate that the shells are each separated by about 800 years.

The spiral is thought to arise because LL Pegasi is a binary system, with the star that is losing material and a companion star orbiting each other. The spacing between layers in the spiral is expected to directly reflect the orbital period of the binary, which is indeed estimated to be also about 800 years.

The creation and shaping of planetary nebulae is an exciting area of stellar evolution. Stars with masses from about half that of the Sun up to about eight times that of the Sun do not explode as supernovae at the ends of their lives. Instead a more regal end awaits them as their outer layers of gas are shed and drift into space, creating striking and intricate structures that to Earth-bound observers often look like dramatic watercolour paintings. IRAS 23166+1655 is just starting this process and the central star has yet to emerge from the cocoon of enveloping dust.

This picture was created from images from the Wide Field Channel of the Advanced Camera for Surveys on Hubble. Images through a yellow filter (F606W, coloured blue) were combined with images through a near-infra red filter (F804W, coloured red). The exposure times were 11 minutes and 22 minutes respectively and the field of view spans about 80 arcseconds.
Data (released)
Font http://www.spacetelescope.org/images/potw1020a/
Autor ESA/NASA & R. Sahai

Llicència

w:ca:Creative Commons
reconeixement
reconeixement
 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:ca:Creative Commons
reconeixement
This file is licensed under the Creative Commons Attribution 4.0 International license.
Reconeixement: ESA/Hubble
Sou lliure de:
  • compartir – copiar, distribuir i comunicar públicament l'obra
  • adaptar – fer-ne obres derivades
Amb les condicions següents:
  • reconeixement – Heu de donar la informació adequada sobre l'autor, proporcionar un enllaç a la llicència i indicar si s'han realitzat canvis. Podeu fer-ho amb qualsevol mitjà raonable, però de cap manera no suggereixi que l'autor us dóna suport o aprova l'ús que en feu.

Llegendes

Afegeix una explicació d'una línia del que representa aquest fitxer

Elements representats en aquest fitxer

representa l'entitat

Historial del fitxer

Cliqueu una data/hora per veure el fitxer tal com era aleshores.

Data/horaMiniaturaDimensionsUsuari/aComentari
actual04:44, 11 abr 2017Miniatura per a la versió del 04:44, 11 abr 20171.625 × 1.625 (1,39 Mo)HuntsterHigher resolution.
04:56, 12 set 2010Miniatura per a la versió del 04:56, 12 set 20101.280 × 1.280 (387 Ko)Igoiam{{Information |Description= |Source= |Date= |Author= |Permission= |other_versions= }}

La pàgina següent utilitza aquest fitxer:

Ús global del fitxer

Utilització d'aquest fitxer en altres wikis:

Metadades

Aquest fitxer conté informació addicional, probablement afegida per la càmera digital o l'escàner utilitzat per a crear-lo o digitalitzar-lo. Si s'ha modificat posteriorment, alguns detalls poden no reflectir les dades reals del fitxer modificat.

Obtingut de «https://ca.wikipedia.org/wiki/Fitxer:Pre-planetary_nebula,_IRAS_23166%2B1655.jpg»