B STARS; NEBULAE; STELLAR SPECTROPHOTOMETRY; SUPERGIANT STARS; BALMER SERIES; CHARGE COUPLED DEVICES; EMISSION SPECTRA; H LINES; PECULIAR STARS; STELLAR SPECTRA
Abstract :
[en] New spectroscopic and direct imagery observations of the supergiant Bep star CD - 42 11721 deg and its surrounding nebula are reported. The spectrum of the star essentially consists of Balmer and Fe II emission lines, He I emission lines are also observed, confirming the presence of spectral variations on long timescales. The clumpy arc-shaped structure of the nebula as well as the presence of motions relative to the central star highly suggest that it has been influenced by a variable mass-loss. The nebula shows both the reflection and emission characteristics. Its spectrum displays the red forbidden N II and S II lines while no oxygen forbidden lines can be detected. Its tempting to interpret this situation by a N/O overabundance which may indicate the presence of processed material in the nebula and thus confirm the evolved nature of the star.
Disciplines :
Space science, astronomy & astrophysics
Author, co-author :
Hutsemekers, Damien ; Université de Liège - ULiège > Département d'astrophys., géophysique et océanographie (AGO) > Astroph. extragalactique et observations spatiales (AEOS)
van Drom, E.
Language :
English
Title :
The supergiant Bep star CD - 42 11721 deg and its surrounding nebula