Searching For 55 Cancri G: A Hardware-To-Planet Approach

Juliana García-Mejía, Jason Eastman, John Johnson
2017 Zenodo  
Humanity's search for exoplanets has led to the discovery of rich and complex planetary systems unlike our own. With its five known planets and the tantalizing hint of more, 55 Cancri is one such system. This thesis takes a "hardware-to-planet" approach in order to search for 55 Cnc g – a sixth planet in the system – by means of the radial velocity (RV) method. This approach required an interdisciplinary effort that involved hardware, software, and analysis projects. I envisioned using the
more » ... VA observatory (Mt.Hopkins, AZ) to obtain new 55 Cnc radial velocity data. Thus, at the instrumentation level, I set out to help expedite MINERVA's ability to fulfill its primary science goal of becoming a dedicated Doppler-based detection facility. Through a collaborative effort, I helped install a new generation of fibers that transmit light from the telescopes to the spectrograph, and improved the throughput of the old set of fibers by a factor of ~ 10. I also helped repair the observatory from an unexpected mechanical failure, and carried out a two-stage snow-protection plan to prevent the failure from happening again. At the software level, I assessed the feasibility of incorporating a 22-parameter model into the MINERVA Doppler reduction pipeline to better characterize its instrumental profile. I found that the model is extremely sensitive to initial conditions, and an automated algorithm that independently fine-tunes the initial guess for each parameter is necessary to achieve convergence. Ultimately, delays due to the fiber installation and the unexpected mechanical failure prevented me from obtaining original 55 Cnc data with MINERVA. Nonetheless, this thesis uses 1602 high precision radial velocity observations of 55 Cancri, including 200 new RVs from the 2017 Keck/HIRES data release, to present an updated study of the system. I employ the EXOFASTv2 IDL software package (Eastman et al., in prep) to obtain a 5-planet radial velocity model of the system, as well as its stellar and planetary parameter estimates an [...]
doi:10.5281/zenodo.573012 fatcat:gld5iljyj5gjzhsjgwetfex6gq