Sirius A and Sirius B (Illustration) : 無料・フリー素材/写真
Sirius A and Sirius B (Illustration) / NASA Hubble
| ライセンス | クリエイティブ・コモンズ 表示 2.1 |
|---|---|
| 説明 | This picture is an artist's impression showing how the binary star system of Sirius A and its diminutive blue companion, Sirius B, might appear to an interstellar visitor. The large, bluish-white star Sirius A dominates the scene, while Sirius B is the small but very hot and blue white-dwarf star on the right. (White dwarfs are the leftover cores of stars similar to our Sun.) The two stars revolve around each other every 50 years. The Sirius system, only 8.6 light-years from Earth, is the fifth closest stellar system known. Sirius B is faint because of its tiny size. Its diameter is only 7,500 miles, slightly smaller than Earth. The Sirius system is so close to Earth that most of the familiar constellations would have nearly the same appearance as in our own sky. In this rendition, we see in the background the three bright stars that make up the Summer Triangle: Altair, Deneb, and Vega. Altair is the white dot above Sirius A; Deneb is the dot to the upper right; and Vega lies below Sirius B. But there is one unfamiliar addition to the constellations: our own Sun is the star shown as a small dot just below and to the right of Sirius A.For more information, visit: hubblesite.org/contents/news-releases/2005/news-2005-36.htmlCredit: NASA, ESA, and G. Bacon (STScI) |
| 撮影日 | 2019-09-30 09:22:15 |
| 撮影者 | NASA Hubble |
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