跳转到内容

File:A curious supernova in NGC 2441.jpg

页面内容不支持其他语言。
這個文件來自維基共享資源
维基百科，自由的百科全书

原始文件 ‎（2,913 × 1,861像素，文件大小：2.89 MB，MIME类型：image/jpeg）

摘要

描述
English: This bright spiral galaxy is known as NGC 2441, located in the northern constellation of Camelopardalis (The Giraffe). However, NGC 2441 is not the only subject of this new Hubble image; the galaxy contains an intriguing supernova named SN1995E, visible as a small dot at the approximate centre of this image. For a labelled view, see potw1425b.

Supernova SN1995E, discovered in 1995 as its name suggests is a type Ia supernova. This kind of supernova is found in binary systems, where one star — a white dwarf — drags matter from its orbiting companion until it becomes unstable and explodes violently. White dwarf stars all become unbalanced once they reach the same mass, meaning that they all form supernovae with the same intrinsic brightness. Because of this, they are used as standard candles to measure distances in the Universe.

But SN1995E may be useful in another way. More recent observations of this supernova have suggested that it may display a phenomenon known as a light echo, where light is scattered and deflected by dust along our line of sight, making it appear to “echo” outwards from the source. In 2006, Hubble observed SN1995E to be fading in a way that suggested its light was being scattered by a surrounding spherical shell of dust. These echoes can be used to probe both the environments around cosmic objects like supernovae, and the characteristics of their progenitor stars. If SN1995E does indeed have a light echo, it would belong to a very elite club; only two other type Ia supernovae have been found to display light echoes (SN1991T and SN1998bu).

NGC 2441 was first seen by Wilhelm Tempel in 1882, a German astronomer with a keen eye for comets. In total, Tempel observed and documented some 21 comets, several of which were named after him.

A version of this image was entered into the Hubble’s Hidden Treasures image processing competition by contestant Nick Rose.
日期
来源 http://www.spacetelescope.org/images/potw1425a/
作者

ESA/Hubble & NASA

Acknowledgement: Nick Rose

许可协议

w:zh:知识共享
署名
署名
 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:知识共享
署名
本文件采用知识共享署名 4.0 国际许可协议授权。
署名: ESA/Hubble
您可以自由地：
  • 共享 – 复制、发行并传播本作品
  • 修改 – 改编作品
惟须遵守下列条件：
  • 署名 – 您必须对作品进行署名，提供授权条款的链接，并说明是否对原始内容进行了更改。您可以用任何合理的方式来署名，但不得以任何方式表明许可人认可您或您的使用。

说明

添加一行文字以描述该文件所表现的内容

此文件中描述的项目

描繪內容

某些值没有维基数据项目

多媒體型式

image/jpeg

核對和

d754c94a8b8a9c78fe5305fdf6aadcdfe6c0ef5f

确定方法：​SHA-1

資料大小

3,035,360 字节

高度

1,861 像素

寬度

2,913 像素

文件历史

点击某个日期/时间查看对应时刻的文件。

日期/时间缩⁠略⁠图大小用户备注
当前2014年6月25日 (三) 14:092014年6月25日 (三) 14:09版本的缩略图2,913 × 1,861（2.89 MB）JmencisomUser created page with UploadWizard

以下页面使用本文件：

全域文件用途

以下其他wiki使用此文件：

元数据

此文件中包含有扩展的信息。这些信息可能是由数码相机或扫描仪在创建或数字化过程中所添加。

如果此文件的源文件已经被修改，一些信息在修改后的文件中将不能完全反映出来。

取自“https://zh.wikipedia.org/wiki/File:A_curious_supernova_in_NGC_2441.jpg”