标签: spectra

辇道增七

2022年2月24日 Beautiful Albireo AB Image Credit & Copyright: Robert Eder Explanation: Beta Cygni is a single bright star to the naked eye. About 420 light-years away it marks the foot of the Northern Cross, famous asterism in the constellation Cygnus. But a view through the eyepiece of a small telescope will transform it into a beautiful double star, a tre...

CG4:破裂的彗星状云球

2021年7月26日 CG4: A Ruptured Cometary Globule Image Credit & Copyright: Nicolas Rolland & Martin Pugh Explanation: Can a gas cloud grab a galaxy? It’s not even close. The “claw” of this odd looking “creature” in the featured photo is a gas cloud known as a cometary globule. This globule, however, has ruptured. Cometary g...

环状星云及附近恒星的色彩

2021年7月21日 Colors: Ring Nebula versus Stars Image Credit: Robert Vanderbei (Princeton U.) Explanation: What if you could see, separately, all the colors of the Ring? And of the surrounding stars? There’s technology for that. The featured image shows the Ring Nebula (M57) and nearby stars through such technology: in this case, a prism-like diffraction g...