The Herschel view of nebulae around evolved massive stars

The detailed study of the nebulae ejected from Luminous Blue Variables and the circumstellar bubbles around Wolf-Rayet stars, which radiate strongly in the IR due to the heating of dust, is crucial for understanding the massive stars evolution. With Herschel, the largest telescope ever flown in space, we are able to study the gas and the dust in these circumstellar environments in the full far-infrared waveband. In the context of 'Mass-loss of Evolved StarS' Herschel guaranteed time key programme, we have obtained imaging and spectroscopic observations of nebulae associated with Luminous Blue Variable and Wolf-Rayet stars using PACS, one of the three instruments onboard Herschel. A description of these observations and first results of the data analysis are presented.