title: Anomalous nitrogen isotope ratio in comets.
abstract: High-resolution spectra of the CN B2 summation operator +-X2 summation operator + (0,0) band at 390 nanometers yield isotopic ratios for comets C/1995 O1 (Hale-Bopp) and C/2000 WM1 (LINEAR) as follows: 165 +/- 40 and 115 +/- 20 for 12C/13C, 140 +/- 35 and 140 +/- 30 for 14N/15N. Our N isotopic measurements are lower than the terrestrial 14N/15N = 272 and the ratio for Hale-Bopp from measurements of HCN, the presumed parent species of CN. This isotopic anomaly suggests the existence of other parent(s) of CN, with an even lower N isotopic ratio. Organic compounds like those found in interplanetary dust particles are good candidates.
authors.affiliation: Institut d'Astrophysique et de Géophysique, Sart-Tilman, Bâtiment B5c, B-4000 Liège, Belgium. Claude.Arpigny@ulg.ac.be
authors.forename: Claude
authors.initials: C
authors.lastname: Arpigny
authors.forename: Emmanuël
authors.initials: E
authors.lastname: Jehin
authors.forename: Jean
authors.initials: J
authors.lastname: Manfroid
authors.forename: Damien
authors.initials: D
authors.lastname: Hutsemékers
authors.forename: Rita
authors.initials: R
authors.lastname: Schulz
authors.forename: J A
authors.initials: JA
authors.lastname: Stüwe
authors.forename: Jean-Marc
authors.initials: JM
authors.lastname: Zucconi
authors.forename: Ilya
authors.initials: I
authors.lastname: Ilyin
mesh_terms: D002247:Carbon Isotopes / Q000032:analysis; D003486:Cyanides / Q000032:analysis; D005453:Fluorescence; D019110:Meteoroids; D009587:Nitrogen Isotopes / Q000032:analysis*; D009930:Organic Chemicals / Q000032:analysis
chemical_list: D002247:Carbon Isotopes; D003486:Cyanides; D009587:Nitrogen Isotopes; D009930:Organic Chemicals