Precision mass ratio of He+3 to HD+

High precision isotope ratio monitoring techniques in mass spectrometry.

Isotope ratio monitoring following on-line combustion is a new method in gas chromatography/mass spectrometry (GC/MS) that allows the ratios of abundances of stable isotopes of elements such as carbon and nitrogen to be determined for individual compounds introduced via a gas chromatograph. It is the first combustion method that allows direct measurement of isotope ratios of individual molecula...

Determination of the antiproton-to-electron mass ratio by precision laser spectroscopy of pHe+.

A femtosecond optical frequency comb and continuous-wave pulse-amplified laser were used to measure 12 transition frequencies of antiprotonic helium to fractional precisions of (9-16)x10(-9). One of these is between two states having microsecond-scale lifetimes hitherto unaccessible to our precision laser spectroscopy method. Comparisons with three-body QED calculations yielded an antiproton-to...

MIMAC-He3 : MIcro-tpc MAtrix of Chambers of He3

The Mass of the Candidate Exoplanet Companion to HD 33636 from HST Astrometry and High-Precision Radial Velocities

We have determined a dynamical mass for the companion to HD 33636 which indicates it is a low-mass star instead of an exoplanet. Our result is based on an analysis of Hubble Space Telescope (HST ) astrometry and ground-based radial velocity data. We have obtained high-cadence radial velocity measurements spanning 1.3 years of HD 33636 with the Hobby-Eberly Telescope at McDonald Observatory. We ...

A High-Eccentricity Low-Mass Companion to HD 89744.

HD 89744 is an F7 V star with a mass of 1.4 M middle dot in circle, an effective temperature of 6166 K, an age of 2.0 Gyr, and metallicity &sqbl0;Fe&solm0;H&sqbr0;=0.18. The radial velocity of the star has been monitored with the Advanced Fiber-Optic Echelle spectrograph at the Whipple Observatory since 1996, and evidence has been found for a low-mass companion. The data were complemented by ad...