Discovering Long-period Exoplanets with Radial Velocities
Open Access
- Author:
- Feng, Ying
- Area of Honors:
- Astronomy and Astrophysics
- Degree:
- Bachelor of Science
- Document Type:
- Thesis
- Thesis Supervisors:
- Jason Thomas Wright, Thesis Supervisor
Jane Camilla Charlton, Thesis Honors Advisor - Keywords:
- astronomy
exoplanets
radial velocity
keck - Abstract:
- The eight planets in the Solar System have been outnumbered by planets orbiting other stars. In the era of extrasolar planet (exoplanet) discoveries, we continue to search for Earth-like planets and Solar System analogs. Jupiter-mass planets in long period orbits (> 1000 days) allow us to examine the frequency of multi-planet systems, systems with structure similar to ours. We present an analysis of almost two dozen Sun-like stars with long-period planets or planetary candidates using the radial velocity method for exoplanet detection. In total, we determine orbital parameters for 33 extrasolar planets. With the most recent radial velocities from the HIRES spectrometer on the W. M. Keck Observatory, we perform Keplerian fits and re-analyze published data from other telescopes. For the first time, we also find the distribution characterizing the o ffset between the data obtained before and after the 2004 HIRES upgrade. We find at least 2 new planets: HD 4203 c and HD 145934 b. Where planetary orbits are incomplete, we construct minimum mass-period diagrams. The o ffset distribution helped constrain the uncertainties for HD 4203 c. Many planets have more re fined orbits with signifi cant decreases in the uncertainties of parameters. We have also constrained a few other orbits, putting upper limits on possible parameters. Three planets are approximate Jupiter "twins": HD 154345 b, HD 114783 c, and HD 47186 c. Among our planetary systems, 13 have at least two planets with well-constrained orbits and masses. By enlarging and improving the sample of long-period planets, we intend to analyze in the future the diversity and trends in planetary systems from our sample and others published in the literature.