Post-AGB star

Post-AGB stars span a large range of temperatures, as they are in the process of heating up from very cool temperatures ( or less) up to about . Technically, the post-AGB stage only ends when the star reaches its maximum temperature of 100-, but beyond , the star ionises the surrounding gas and would be considered a central star of a planetary nebula more often than a post-AGB star. On the other hand, the luminosity of post-AGB stars is usually constant throughout the post-AGB stage, and slightly dependent on the star's core mass, and getting slightly brighter with lower metallicity. == Examples ==

Due to the dust usually obscuring them, many post-AGB stars are visually relatively dim. However there are still some post-AGB stars visible to the naked eye, the brightest of which is 89 Herculis. Other examples include: • RV Tauri • R Scuti • U Monocerotis ==References==