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.

Credit:

ESO

Over de afbeelding

Id:eso0129b
Type:Kaart
Publicatiedatum:22 augustus 2001
Gerelateerde berichten:eso0129
Grootte:800 x 612 px

Over het object

Naam:HD 196944
Type:Milky Way : Star
Afstand:1500 lichtjaren
Categorie:Stars

Afbeeldingstypen

Grote JPEG
121,6 KB

Kleuren & filters

BandGolflengteTelescoop
Optisch
V
405 nmESO 3.6-metre telescope
Coudé Echelle Spectrometer (CES)