ファイル:A case of suspended animation.jpg

元のファイル(1,280 × 775 ピクセル、ファイルサイズ: 400キロバイト、MIME タイプ: image/jpeg)

概要

解説
English: At first glance this NASA/ESA Hubble Space Telescope image seems to show an array of different cosmic objects, but the speckling of stars shown here actually forms a single body — a nearby dwarf galaxy known as Leo A. Its few million stars are so sparsely distributed that some distant background galaxies are visible through it. Leo A itself is at a distance of about 2.5 million light-years from Earth and a member of the Local Group of galaxies; a group that includes the Milky Way and the well-known Andromeda galaxy.

Astronomers study dwarf galaxies because they are very numerous and are simpler in structure than their giant cousins. However, their small size makes them difficult to study at great distances. As a result, the dwarf galaxies of the Local Group are of particular interest, as they are close enough to study in detail.

As it turns out, Leo A is a rather unusual galaxy. It is one of the most isolated galaxies in the Local Group, has no obvious structural features beyond being a roughly spherical mass of stars, and shows no evidence for recent interactions with any of its few neighbours. However, the galaxy’s contents are overwhelmingly dominated by relatively young stars, something that would normally be the result of a recent interaction with another galaxy. Around 90% of the stars in Leo A are less than eight billion years old — young in cosmic terms! This raises a number of intriguing questions about why star formation in Leo A did not take place on the “usual” timescale, but instead waited until it was good and ready.
日付
原典 http://www.spacetelescope.org/images/potw1615a/
作者

ESA/Hubble & NASA

Acknowledgement: Judy Schmidt (Geckzilla)

ライセンス

w:ja:クリエイティブ・コモンズ
表示
表示
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:ja:クリエイティブ・コモンズ
表示
このファイルはクリエイティブ・コモンズ 表示 4.0 国際ライセンスのもとに利用を許諾されています。
帰属: ESA/Hubble
あなたは以下の条件に従う場合に限り、自由に
  • 共有 – 本作品を複製、頒布、展示、実演できます。
  • 再構成 – 二次的著作物を作成できます。
あなたの従うべき条件は以下の通りです。
  • 表示 – あなたは適切なクレジットを表示し、ライセンスへのリンクを提供し、変更があったらその旨を示さなければなりません。これらは合理的であればどのような方法で行っても構いませんが、許諾者があなたやあなたの利用行為を支持していると示唆するような方法は除きます。

キャプション

このファイルの内容を1行で記述してください

このファイルに描写されている項目

題材

11 4 2016

057de6810d8086c5957d2e9c699436ba42931ceb

409,929 バイト

775 ピクセル

1,280 ピクセル

ファイルの履歴

過去の版のファイルを表示するには、その版の日時をクリックしてください。

日付と時刻サムネイル寸法利用者コメント
現在の版2016年4月11日 (月) 10:542016年4月11日 (月) 10:54時点における版のサムネイル1,280 × 775 (400キロバイト)JmencisomUser created page with UploadWizard

以下のページがこのファイルを使用しています:

グローバルなファイル使用状況

以下に挙げる他のウィキがこの画像を使っています:

メタデータ