Heavy metal stars

A high-resolution spectrum of the CH-star HD 196944, obtained with the CES instrument on the ESO 3.6-m telescope in September 2000. The observed spectrum (dots) shows many absorption lines from elements that are usually seen in stars. The red line shows a model in which elements (in particular those produced by the s-process) are present in normal quantities, compared to Iron. The blue line instead shows a model where s-processing has occured. It is obvious that the red line does not fit, only the blue line reproduces the observed absorption line at wavelength 405.781 nm caused by Lead (Pb) atoms in the atmosphere of this star. A subsequent, detailed analysis demonstrated that HD 196944 is a true "Lead star".

Technical information: this image shows a small section of the reduced spectrum of the CH-star HD 196944, near wavelength 4050 Angstrom. It was obtained during a 90-min exposure with the Coude Echelle Spectrometer at the ESO 3.6-m telescope on La Silla in 16 September 2000. The spectral resolution is 135 000.

Crédit:

ESO

À propos de l'image

Identification:eso0129b
Type:Graphique
Date de publication:22 août 2001
Communiqués de presse en rapport:eso0129
Taille:800 x 612 px

À propos de l'objet

Nom:HD 196944
Type:Milky Way : Star
Distance:1500 années lumière
Catégorie:Stars

Image Formats

Grand JPEG
121,6 Kio
JPEG taille écran
144,2 Kio

Couleurs & filtres

DomaineLongueur d'ondeTélescope
Visible
V
405 nmESO 3.6-metre telescope
Coudé Echelle Spectrometer (CES)