原始檔案 (1,280 × 1,291 像素,檔案大小:252 KB,MIME 類型:image/jpeg


摘要

描述
English: This colourful bubble is a planetary nebula called NGC 6818, also known as the Little Gem Nebula. It is located in the constellation of Sagittarius (The Archer), roughly 6000 light-years away from us. The rich glow of the cloud is just over half a light-year across — humongous compared to its tiny central star — but still a little gem on a cosmic scale.

When stars like the Sun enter retirement, they shed their outer layers into space to create glowing clouds of gas called planetary nebulae. This ejection of mass is uneven, and planetary nebulae can have very complex shapes. NGC 6818 shows knotty filament-like structures and distinct layers of material, with a bright and enclosed central bubble surrounded by a larger, more diffuse cloud.

Scientists believe that the stellar wind from the central star propels the outflowing material, sculpting the elongated shape of NGC 6818. As this fast wind smashes through the slower-moving cloud it creates particularly bright blowouts at the bubble’s outer layers.

Hubble previously imaged this nebula back in 1997 with its Wide Field Planetary Camera 2, using a mix of filters that highlighted emission from ionised oxygen and hydrogen (opo9811h). This image, while from the same camera, uses different filters to reveal a different view of the nebula. A version of the image was submitted to the Hubble’s Hidden Treasures image processing competition by contestant Judy Schmidt.
日期
來源 http://www.spacetelescope.org/images/potw1531a/
作者

ESA/Hubble & NASA

Acknowledgement: Judy Schmidt (geckzilla.com)

授權條款

w:zh:共享創意
姓名標示
姓名標示
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:zh:共享創意
姓名標示
此檔案採用創用CC 姓名標示 4.0 國際授權條款。
姓名標示: ESA/Hubble
您可以自由:
  • 分享 – 複製、發佈和傳播本作品
  • 重新修改 – 創作演繹作品
惟需遵照下列條件:
  • 姓名標示 – 您必須指名出正確的製作者,和提供授權條款的連結,以及表示是否有對內容上做出變更。您可以用任何合理的方式來行動,但不得以任何方式表明授權條款是對您許可或是由您所使用。

說明

添加單行說明來描述出檔案所代表的內容

在此檔案描寫的項目

描繪內容

著作權狀態 繁體中文 (已轉換拼寫)

有著作權 繁體中文 (已轉換拼寫)

檔案歷史

點選日期/時間以檢視該時間的檔案版本。

日期/時間縮⁠圖尺寸用戶備⁠註
目前2015年8月3日 (一) 09:57於 2015年8月3日 (一) 09:57 版本的縮圖1,280 × 1,291(252 KB)JmencisomUser created page with UploadWizard

下列頁面有用到此檔案:

全域檔案使用狀況

以下其他 wiki 使用了這個檔案:

詮釋資料