2023年4月7日
Rigel Wide
Image Credit: Rheinhold Wittich
Explanation: Brilliant, blue, supergiant star Rigel marks the foot of Orion the Hunter in planet Earth’s night. Designated Beta Orionis, it’s at the center of this remarkably deep and wide field of view. Rigel’s blue color indicates that it is much hotter than its rival supergiant in Orion the yellowish Betelgeuse (Alpha Orionis), though both stars are massive enough to eventually end their days as core collapse supernovae. Some 860 light-years away, Rigel is hotter than the Sun too and extends to about 74 times the solar radius. That’s about the size of the orbit of Mercury. In the 10 degree wide frame toward the nebula rich constellation, the Orion Nebula is at the upper left. To the right of Rigel and illuminated by its brilliant blue starlight lies the dusty Witch Head Nebula. Rigel is part of a multiple star system, though its companion stars are much fainter.
Tomorrow’s picture: a grand design
参宿七的大视野影像
影像提供: Rheinhold Wittich
说明: 在地球的夜空中，明亮泛蓝的超巨星参宿七位在猎户座的足部。在这幅极深空的广视野影像里，定名为猎户β星的参宿七，位于这片非常深且宽的视野之中心。参宿七的泛蓝星色显示，它远比在猎户座里与它争辉的泛黄参宿四（猎户α星）炽热，不过二者的质量都够大，最终都会以星核崩塌超新星爆炸的方式结束生命。距离地球约860光年远的参宿七，也比太阳要炽热，半径则是太阳的74倍之多，故其外围大约可伸展到水星轨道附近。在这片呈现星云密布的猎户座之10度宽视野里，猎户大星云位于左上角。在参宿七的右侧，可见到被它明亮泛蓝星光照亮的女巫头星云。参宿七是一个多星系统的成员，不过它的伴星都很昏暗。
明日的图片: a grand design
