Deciphering the Atmospheric Composition of WASP-12b: A Comprehensive Analysis of its Dayside Emission

WASP-12b was the first planet reported to have a carbon-to-oxygen ratio (C/O) greater than one in its dayside atmosphere. However, recent work to further characterize its atmosphere and confirm its composition has led to incompatible measurements and divergent conclusions. Additionally, the recent discovery of stellar binary companions ~1" from WASP-12 further complicates the analyses and subsequent interpretations. We present a uniform analysis of all available Hubble and Spitzer Space Telescope secondary-eclipse data, including previously-unpublished Spitzer measurements at 3.6 and 4.5 microns. The primary controversy in the literature has centered on the value and interpretation of the eclipse depth at 4.5 microns. Our new measurements and analyses confirm the shallow eclipse depth in this channel, as first reported by Campo and collaborators and used by Madhusudhan and collaborators to infer a carbon-rich composition. To explain WASP-12b's observed dayside emission spectrum, we implemented several recent retrieval approaches. We find that when we exclude absorption due to C2H2 and HCN, which are not universally considered in the literature, our models require implausibly large atmospheric CO2 abundances, regardless of the C/O. By including C2H2 and HCN in our models, we find that a physically-plausible carbon-rich solution achieves the best fit to the available photometric and spectroscopic data. In comparison, the best-fit oxygen-rich models have abundances that are inconsistent with the chemical equilibrium expectations for hydrogen-dominated atmospheres and are 670 times less probable. Our best-fit solution is also 7.3*10^{6} times more probable than an isothermal blackbody model.Comment: 8 pages, 7 figures, accepted for publication in Ap

Service-learning: Effectively Transitioning Students Into the Workplace

Service-learning is a method of learning that is meant to integrate the needs of the community with the academic curriculum of the students. This method allows for the work of the students, emerging professionals, to be used outside of the school, serving as a test of the skills that students may have only used in a school setting. Students are assigned the task of completing a project for a community organization who is without the resources to complete the project. Matching students who need experience with community organizations who are in need of professional services is an effective method of easing the student’s transition from a school setting into the workplace. Obtaining a job, even with a degree, is not a simple task. In order to obtain a job, you must have skills, proof of skills, and social connections. By providing students with an opportunity to do service-learning, they are able to improve all three of these requirements. My poster will share my experiences with service-learning. At EWU, I have worked with iFixit, a company that creates repair manuals, and with Teen & Kid Closet, a local organization that provides foster youth and youth experiencing homelessness with clothes. The projects completed for these two organizations have provided me with skills, proof of skills, and social connections helping me to comfortably transition into the workplace

Shots, Everybody? : British Anti-smallpox Vaccination and the Development of Multifaceted Anti-vaccine Rhetoric on Internet Parenting Forums

Vaccination is an important public health measure that can help reduce disease at the population level. Substantial evidence exists that vaccines are safe and effective at reducing the incidence of diseases like pertussis, measles and cervical cancer. However, on Internet parenting forums, parents discuss whether or not vaccination is the right choice for their children. In this thesis, I highlight the historical context of the anti-vaccine movement in mid 19th century to early 20th century Victorian Britain in the era of compulsory smallpox vaccination. Vaccination in this time was a very different and more overtly dangerous process, and preexisting dissenting movements took up anti-vaccination as a cause. Today, the rhetoric on Internet parenting forums has grown to include arguments of safety, efficacy and necessity of vaccination. I gathered much of the information from the mothering.com and mumsnet.com parenting forums, and other websites like Sanevax.org

Delayed Recombination and Cosmic Parameters

Current cosmological constraints from Cosmic Microwave Background (CMB) anisotropies are typically derived assuming a standard recombination scheme, however additional resonance and ionizing radiation sources can delay recombination, altering the cosmic ionization history and the cosmological inferences drawn from CMB data. We show that for recent observations of CMB anisotropy, from the Wilkinson Microwave Anisotropy Probe satellite mission 5-year survey (WMAP5) and from the ACBAR experiment, additional resonance radiation is nearly degenerate with variations in the spectral index, n_s, and has a marked effect on uncertainties in constraints on the Hubble constant, age of the universe, curvature and the upper bound on the neutrino mass. When a modified recombination scheme is considered, the redshift of recombination is constrained to z_*=1078\pm11, with uncertainties in the measurement weaker by one order of magnitude than those obtained under the assumption of standard recombination while constraints on the shift parameter are shifted by 1-sigma to R=1.734\pm0.028. Although delayed recombination limits the precision of parameter estimation from the WMAP satellite, we demonstrate that this should not be the case for future, smaller angular scales measurements, such as those by the Planck satellite mission.Comment: 9 pages, 9 figure

New Analysis Indicates No Thermal Inversion in the Atmosphere of HD 209458b

An important focus of exoplanet research is the determination of the atmospheric temperature structure of strongly irradiated gas giant planets, or hot Jupiters. HD 209458b is the prototypical exoplanet for atmospheric thermal inversions, but this assertion does not take into account recently obtained data or newer data reduction techniques. We re-examine this claim by investigating all publicly available Spitzer Space Telescope secondary-eclipse photometric data of HD 209458b and performing a self-consistent analysis. We employ data reduction techniques that minimize stellar centroid variations, apply sophisticated models to known Spitzer systematics, and account for time-correlated noise in the data. We derive new secondary-eclipse depths of 0.119 +/- 0.007%, 0.123 +/- 0.006%, 0.134 +/- 0.035%, and 0.215 +/- 0.008% in the 3.6, 4.5, 5.8, and 8.0 micron bandpasses, respectively. We feed these results into a Bayesian atmospheric retrieval analysis and determine that it is unnecessary to invoke a thermal inversion to explain our secondary-eclipse depths. The data are well-fitted by a temperature model that decreases monotonically between pressure levels of 1 and 0.01 bars. We conclude that there is no evidence for a thermal inversion in the atmosphere of HD 209458b.Comment: 8 pages, 5 figures; accepted for publication in Ap

Comparing key compositional indicators in Jupiter with those in extra-solar giant planets

Spectroscopic transiting observations of the atmospheres of hot Jupiters around other stars, first with Hubble Space Telescope and then Spitzer, opened the door to compositional studies of exoplanets. The James Webb Space Telescope will provide such a profound improvement in signal-to-noise ratio that it will enable detailed analysis of molecular abundances, including but not limited to determining abundances of all the major carbon- and oxygen-bearing species in hot Jupiter atmospheres. This will allow determination of the carbon-to-oxygen ratio, an essential number for planet formation models and a motivating goal of the Juno mission currently around JupiterComment: Submitted to the Astro2020 Decadal Survey as a white paper; thematic areas "Planetary Systems" and "Star and Planet Formation

Volatiles in glasses from the HSDP2 drill core

H2O, CO2, S, Cl, and F concentrations are reported for 556 glasses from the submarine section of the 1999 phase of HSDP drilling in Hilo, Hawaii, providing a high-resolution record of magmatic volatiles over ~200 kyr of a Hawaiian volcano's lifetime. Glasses range from undegassed to having lost significant volatiles at near-atmospheric pressure. Nearly all hyaloclastite glasses are degassed, compatible with formation from subaerial lavas that fragmented on entering the ocean and were transported by gravity flows down the volcano flank. Most pillows are undegassed, indicating submarine eruption. The shallowest pillows and most massive lavas are degassed, suggesting formation by subaerial flows that penetrated the shoreline and flowed some distance under water. Some pillow rim glasses have H2O and S contents indicating degassing but elevated CO2 contents that correlate with depth in the core; these tend to be more fractionated and could have formed by mixing of degassed, fractionated magmas with undegassed magmas during magma chamber overturn or by resorption of rising CO2-rich bubbles by degassed magmas. Intrusive glasses are undegassed and have CO2 contents similar to adjacent pillows, indicating intrusion shallow in the volcanic edifice. Cl correlates weakly with H2O and S, suggesting loss during low-pressure degassing, although most samples appear contaminated by seawater-derived components. F behaves as an involatile incompatible element. Fractionation trends were modeled using MELTS. Degassed glasses require fractionation at pH2O ≈ 5–10 bars. Undegassed low-SiO2 glasses require fractionation at pH2O ≈ 50 bars. Undegassed and partially degassed high-SiO2 glasses can be modeled by coupled crystallization and degassing. Eruption depths of undegassed pillows can be calculated from their volatile contents assuming vapor saturation. The amount of subsidence can be determined from the difference between this depth and the sample's depth in the core. Assuming subsidence at 2.5 mm/y, the amount of subsidence suggests ages of ~500 ka for samples from the lower 750 m of the core, consistent with radiometric ages. H2O contents of undegassed low-SiO2 HSDP2 glasses are systematically higher than those of high-SiO2 glasses, and their H2O/K2O and H2O/Ce ratios are higher than typical tholeiitic pillow rim glasses from Hawaiian volcanoes

Systematic Atmospheric Refreaction Errors of Baseline Type Radio Tracking Systems and Methods for their Correction

The theory of systematic atmospheric radio refraction errors affecting measurements of range and range differences (and associated time rate of change of these quantities) is developed. It is shown that the refraction errors, particularly in range difference measurements, can seriously affect the accuracy of baseline-type tracking systems. A method is derived by which the systematic portion of tL.ese errors can be removed by means of linear relationships involving the surface value of the radio refractive index; the correction process cievlsea can be used in real time if desired. Several test cases are examined where horizontally-varying profiles of the refractive index variation with height are used to calculate the errors, and the correction process based on surface refractive index values is found to be useful under these more general conditions. Approximately 98 percent of the total range or rangt difference error can be removed using this correction procedure. The problem of baseline optimization for deep-space tracking is examined briefly, and it is shown that a baseline length of about 4, 000 miles is optimal for targets more than about 6, 000 miles from the earth, and foi such a system residual atmospheric refraction errors would be only a fe\\ hundredths of a microradian, assuming the validity of ray optics and of the models of the atmosphere used in this paper