韦伯影像: 星团IC 348

2024年1月15日

Star Cluster IC 348 from Webb
Image Credit: NASA, ESA, CSA, STScI, and K. Luhman (Penn State U.) and C. Alves de Oliveira (ESA)

Explanation: Sometimes, it’s the stars that are the hardest to see that are the most interesting. IC 348 is a young star cluster that illuminates surrounding filamentary dust. The stringy and winding dust appears pink in this recently released infrared image from the Webb Space Telescope. In visible light, this dust reflects mostly blue light, giving the surrounding material the familiar blue hue of a reflection nebula. Besides bright stars, several cool objects have been located in IC 348, visible because they glow brighter in infrared light. These objects are hypothesized to be low mass brown dwarfs. Evidence for this includes the detection of an unidentified atmospheric chemical, likely a hydrocarbon, seen previously in the atmosphere of Saturn. These objects appear to have masses slightly greater than known planets, only a few times greater than Jupiter. Together, these indicate that this young star cluster contains something noteworthy — young planet-mass brown dwarfs that float free, not orbiting any other star.

Tomorrow’s picture: almost orion

韦伯影像: 星团IC 348
影像提供: NASA, ESA, CSA, STScI, and K. Luhman (Penn State U.) and C. Alves de Oliveira (ESA)

说明: 有时候，最难见到的恒星才最有趣。年轻的星团IC 348，照亮了周围的细丝状尘埃。在韦伯太空望远镜最近发布的这张红外光影像里，这些卷曲细丝状尘埃带着粉红的色泽。在可见光波段，这些尘埃以反射蓝光为主，因此星团周围的物质，会带着反射星云熟悉的泛蓝色调。除了明亮的恒星之外，在IC 348 里还找到数个低温天体，这些天体之所以可见，则是它们在红外光波段很明亮。假说认为这些天体可能是小质量的棕矮星。支持这种说法的证据，包括侦测到一种不明的大气化学物质，而它很可能是先前发现于土星大气中的碳氢化合物。这些天体的质量似乎略大于已知的行星，仅是木星的数倍之多。总之，迹证显示这个年轻星团拥有值得关注的天体，特别是指质量和行星相近、自由漂浮并未绕行任何恒星的棕矮星。