正向星系NGC 6946

正向星系NGC 6946

Facing NGC 6946
Image Credit & Copyright: Roberto Marinoni

Explanation: From our vantage point in the Milky Way Galaxy, we see NGC 6946 face-on. The big, beautiful spiral galaxy is located just 20 million light-years away, behind a veil of foreground dust and stars in the high and far-off constellation Cepheus. In this sharp telescopic portrait, from the core outward the galaxy’s colors change from the yellowish light of old stars in the center to young blue star clusters and reddish star forming regions along the loose, fragmented spiral arms. NGC 6946 is also bright in infrared light and rich in gas and dust, exhibiting a high star birth and death rate. In fact, since the early 20th century ten confirmed supernovae, the death explosions of massive stars, were discovered in NGC 6946. Nearly 40,000 light-years across, NGC 6946 is also known as the Fireworks Galaxy.

Tomorrow’s picture: Saturnday

正向星系NGC 6946
影像提供与版权: Roberto Marinoni

说明: 从银河系我们所在的位置看出去，星系NGC 6946刚好正向着我们。这个庞大的美丽螺旋星系离我们只有2千万光年远，隐藏在北天仙王座的前景尘埃和恒星所构成的薄纱后方。在这幅清晰的望远镜影像里，从明亮的核心往外，星系的色泽从核心年老恒星的黄色，转变成散布在松散且断断续续的螺旋臂上的泛蓝星团和泛红恒星形成区。富含气体与尘埃的6949，是个在红外光波段很明亮的星系，并具有很高的恒星形成率与死亡率。事实上，自20世纪初以来，已在NGC 6946里发现了10例获得证实的恒星死亡爆炸所产生的超新星事件。将近40,000光年宽的NGC 6946，也拥有烟火星系的称号。

明日的图片: Saturnday