Discipline: Physics
Subcategory: Astronomy and Astrophysics
Session: 1
Room: Park Tower 8216
Hector E. Delgado Diaz - California State University, Los Angeles
Co-Author(s): Renyu Hu, California Institute of Technology, Pasadena, CA
The detection of exoplanets began with the discovery of 51 Pegasi-b in 1995. Afterwards, satellites such as Kepler, K2, and ground-based telescopes have detected around 3,750 exoplanets with characteristics incomparable to the planets found in our Solar System. However, there are about 10 medium and small exoplanets that sparked interest in continuing to study their atmospheres. With the help of the Transiting Exoplanet Survey Satellite (TESS), more planets will be added to this sample.
The type of planets of interest are rocky planets, which are dependent of the atmospheric conditions in order to be habitable. We will focus in two atmospheric scenarios known to lead to future habitability of the planet: H2/He dominant atmosphere and secondary atmosphere ranging from N2 to CO2. Furthermore, the exoplanet would consist of large bodies of water (i.e. oceans), which played an important role in the evolution of life on Earth. We will determine the stability of nitrogen-containing compounds because it is hypothesized that NH3, HNO3, and HNO4 can be loss due to their solubility in water and thus, depleting the nitrogen from the atmosphere. Molecules such as N2, NH3 are important because they are greenhouse gases that maintain the planet’s temperature above the freezing point of water. The lifetimes and long-term stability will be determine using an advance atmospheric chemistry and radiative transfer code (Hu et al. 2012) written in C and the graphs will be plotted using MATLAB. No preliminary results have been achieved, yet they will be expected before February 2019. This research is important because understanding the atmospheric scenarios that can produce a habitable planet are needed to guide and maximize the efficiency of the future space missions of exoplanet surveys.
References: Kasting, James F., Daniel P. Whitmire, and Ray T. Reynolds. ‘Habitable zones around main sequence stars.’ Icarus 101.1 (1993): 108-128. Pierrehumbert, Raymond, and Eric Gaidos. ‘Hydrogen greenhouse planets beyond the habitable zone.’ The Astrophysical Journal Letters 734.1 (2011): L13. Renyu Hu, Sara Seager, and William Bains. ‘Photochemistry in Terrestrial Exoplanet Atmospheres I: Photochemistry Model and Benchmark Cases.’ ApJ 761 (2012): 166. Sara Seager, William Bains, and Renyu Hu. ‘Biosignature Gases in H2- Dominated Exoplanet Atmospheres.’ ApJ 777 (2013): 95. Wong, Michael L., et al. ‘The photochemistry of Pluto’s atmosphere as illuminated by New Horizons.’ Icarus 287 (2017): 110-115.
Funder Acknowledgement(s): Funder Acknowledgement: I would like to thank the National Institute of General Medical Sciences of the National Institute of Health for providing the funding under Award Number R25GM061331. I also would like to thank NASA's Jet Propulsion Laboratory for giving me the opportunity to participate in the JPL Visiting Student Research Program and make the work possible. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institute of Health.
Faculty Advisor: Dr. Renyu Hu, renyu.hu@jpl.nasa.gov
Role: I have done literature review of this research, along with starting to manipulate the atmospheric chemistry and radiative transfer code to begin the atmospheric model of the rocky planets. I also have started plotting the data from the models.