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We present the discovery of TOI-1994b, a low-mass brown dwarf transiting a hot subgiant star on a moderately eccentric orbit. TOI-1994 has an effective temperature of $7700^{+720}_{-410}$ K, V magnitude of 10.51 mag and log(g) of $3.982^{+0.067}_{-0.065}$. The brown dwarf has a mass of $22.1^{+2.6}_{-2.5}$ $M_J$, a period of 4.034 days, an eccentricity of $0.341^{+0.054}_{-0.059}$, and a radius of $1.220^{+0.082}_{-0.071}$ $R_J$. TOI-1994b is more eccentric than other transiting brown dwarfs with similar masses and periods. The population of low mass brown dwarfs may have properties similar to planetary systems if they were formed in the same way, but the short orbital period and high eccentricity of TOI-1994b may contrast this theory. An evolved host provides a valuable opportunity to understand the influence stellar evolution has on the substellar companion's fundamental properties. With precise age, mass, and radius, the global analysis and characterization of TOI-1994b augments the small number of transiting brown dwarfs and allows the testing of substellar evolution models., 12 pages, 7 figures, Submitted to AAS Journals

Funding: TGW, ACC, and KH acknowledge support from STFC consolidated grant numbers ST/R000824/1 and ST/V000861/1, and UKSA grant ST/R003203/1. We present the discovery of two exoplanets transiting TOI-836 (TIC 440887364) using data from TESS Sector 11 and Sector 38. TOI-836 is a bright (T = 8.5 mag), high proper motion (∼200 mas yr−1), low metallicity ([Fe/H]≈−0.28) K-dwarf with a mass of 0.68 ± 0.05 M⊙ and a radius of 0.67 ± 0.01 R⊙. We obtain photometric follow-up observations with a variety of facilities, and we use these data-sets to determine that the inner planet, TOI-836 b, is a 1.70 ± 0.07 R⊕ super-Earth in a 3.82 day orbit, placing it directly within the so-called ‘radius valley’. The outer planet, TOI-836 c, is a 2.59 ± 0.09 R⊕ mini-Neptune in an 8.60 day orbit. Radial velocity measurements reveal that TOI-836 b has a mass of 4.5 ± 0.9 M⊕, while TOI-836 c has a mass of 9.6 ± 2.6 M⊕. Photometric observations show Transit Timing Variations (TTVs) on the order of 20 minutes for TOI-836 c, although there are no detectable TTVs for TOI-836 b. The TTVs of planet TOI-836 c may be caused by an undetected exterior planet. Publisher PDF

The CRED2 camera detects near-infrared wavelengths of light from 1 to 1.7 microns. I used the provided graphical user interface (GUI) to take images on the camera. Later, I used a Git BASH command line to compile and run the python code for controlling the camera. Once this control software is complete in the future, the camera will be mounted on George Mason's Campus Telescope. I also assisted in repairing the charge-coupled device (CCD) detector, a SBIG-16803 model, after several wires had broken this summer. After the camera was taken apart, I helped strip the ends of each wire, and then twisting them with their corresponding wires on the other end. I consolidated the connection of the wires by twisting and soldering them together., Journal of Student-Scientists' Research, Vol. 3 (2021)

Astronomers have confirmed over 4,000 exoplanets, planets that orbit other stars..This research, as part of the TESS Follow-up Observation Program (TFOP), aims to find and confirm new exoplanets by characterizing potential TESS Objects of Interest (TOIs) as either exoplanet detections or false positives generated from nearby blended/eclipsing binary stars. Candidates were found by the NASA TESS mission -- NASA's Transiting Exoplanet Survey Satellite (TESS). Based on the transit method, which consists of looking at dips in brightness in the light curve of a star during an exoplanet transit,.we collected images of multiple TOIs using the 0.8 meter telescope located at the George Mason University Observatory. We processed the data with the python programming language to reduce image and detector noise. Light Curves were generated by the image processing software AstroImageJ. Transits of the target were.modeled through the software package EXOFASTv2, and were finally uploaded to ExoFop TESS, a website developed by NASA Exoplanet Science Institute and NASA Exoplanet Archive to facilitate collaboration between researchers. Findings from this data analysis have contributed to multiple TOI detections and continue to expand the validation of candidates from the TESS mission., Journal of Student-Scientists' Research, Vol. 3 (2021)

One of the primary goals of exoplanet science has been to precisely measure the abundances of key species in and metallicities of exoplanet atmospheres to gain information on their formation conditions. This information has generally been limited in the past by the low resolution and narrow wavelength coverage of space-based observatories such as the Hubble and Spitzer Space Telescopes. Recently, the method of high-resolution cross-correlation analysis has emerged as an alternative way to precisely measure the abundances of a variety of species in exoplanet atmospheres using ground-based telescopes. Here we present the first results from a large program to measure high-resolution transmission spectra of 11 giant exoplanets using the IGRINS instrument on Gemini-S. We describe the goals of this ongoing program and show results from a high-resolution transit of the ultra-hot Jupiter WASP-76b. We present measurements of the abundances of key molecules, including water, CO, FeH, and OH, in the atmosphere of WASP-76b and use these measurements to precisely constrain its overall metallicity and C/O ratio.

Precise mass measurements of exoplanets discovered by the direct imaging or transit technique are required to determine planet bulk properties and potential habitability. Furthermore, it is generally acknowledged that, for the foreseeable future, the Extreme Precision Radial Velocity (EPRV) measurement technique is the only method potentially capable of detecting and measuring the masses and orbits of habitable-zone Earths orbiting nearby F, G, and K spectral-type stars from the ground. In particular, EPRV measurements with a precision of better than approximately 10 cm/s (with a few cm/s stability over many years) are required. Unfortunately, for nearly a decade, PRV instruments and surveys have been unable to routinely reach RV accuracies of less than roughly 1 m/s. Making EPRV science and technology development a critical component of both NASA and NSF program plans is crucial for reaching the goal of detecting potentially habitable Earthlike planets and supporting potential future exoplanet direct imaging missions such as the Habitable Exoplanet Observatory (HabEx) or the Large Ultraviolet Optical Infrared Surveyor (LUVOIR). In recognition of these facts, the 2018 National Academy of Sciences (NAS) Exoplanet Science Strategy (ESS) report recommended the development of EPRV measurements as a critical step toward the detection and characterization of habitable, Earth-analog planets. In response to the NAS-ESS recommendation, NASA and NSF commissioned the EPRV Working Group to recommend a ground-based program architecture and implementation plan to achieve the goal intended by the NAS. This report documents the activities, findings, and recommendations of the EPRV Working Group., Full report: 103 pages. Executive summary: 7 pages. More information about the NASA-NSF Exoplanet Observational Research (NN-EXPLORE) program, including the NASA-NSF Extreme Precision Radial Velocity Initiative, can be found here: https://exoplanets.nasa.gov/exep/NNExplore/

We present a unique implementation of python coding in an asynchronous object-oriented framework to fully automate the process of collecting data with the George Mason University Observatory’s 0.8-meter telescope. The goal of this project is to streamline the process of collecting research data and monitoring weather, most often for follow-up observations for the TESS mission. We have automated slews and dome movements, CCD exposures, saving FITS images, focusing and guiding on the target, and taking calibration images (darks and flats). We also have automated periodically checking weather conditions to automate the decision-making involved in whether a shutdown is necessary. We are now able to input the specifications of the desired target in a user-friendly GUI that generates an input configuration file and launches the command-line code at the beginning of the night. The code, in its current state, has been tested and used for observations without error on at least 110 nights., {"references":["W. J. Borucki, D. Koch, G. Basri, et al., \"Kepler planet-detection mission: Introduction and first results,\" Science 327(5968), 977–980 (2010).","G. R. Ricker, J. N. Winn, R. Vanderspek, et al., \"Transiting Exoplanet Survey Satellite,\" Journal of Astronomical Telescopes, Instruments, and Systems 1(1), 1 – 10 (2014).","D. Nesvorny and A. Morbidelli, \"Mass and orbit determination from transit timing variations of exoplanets,\" The Astrophysical Journal 688, 636–646 (2008).","C. Baranec, R. Riddle, A. N. Ramaprakash, et al., \"Robo-ao: autonomous and replicable laser-adaptive-optics and science system,\" Adaptive Optics Systems III (2012).","J. J. Swift, M. Bottom, J. A. Johnson, et al., \"Miniature exoplanet radial velocity array i: design, commissioning, and early photometric results,\" Journal of Astronomical Telescopes, Instruments, and Systems 1, 027002 (2015).","J. Eastman, B. S. Gaudi, R. Siverd, et al., \"DEMONEX: the DEdicated MONitor of EXo-transits,\" in Ground-based and Airborne Telescopes III, L. M. Stepp, R. Gilmozzi, and H. J. Hall, Eds., 7733, 1243 – 1250, International Society for Optics and Photonics, SPIE (2010).","K. Collins and J. Kielkopf, \"Astroimagej: Imagej for astronomy,\" (2013). Astrophysics source code library."]}

Our ability to answer scientific questions about exoplanets hinges on satisfying an age-old astronomical requirement: a sufficient sample size. Thus, the yield of exoplanets is critical to understanding the scientific impact of future missions. We discuss how the yield of directly-imaged exoplanets depends on mission scale and survey design.

We report measurements of the sky-projected spin-orbit angle for AU\,Mic\,b, a Neptune-size planet orbiting a very young ($\sim20$\,Myr) nearby pre-main sequence M dwarf star which also hosts a bright, edge-on, debris disk. The planet was recently discovered from preliminary analysis of radial velocity observations and confirmed to be transiting its host star from photometric data from the NASA's \textit{TESS} mission. We obtained radial velocity measurements of AU\,Mic over the course of two partially observable transits and one full transit of planet b from high-resolution spectroscopic observations made with the {\textsc{Minerva}}-Australis telescope array. Only a marginal detection of the Rossiter--McLaughlin effect signal was obtained from the radial velocities, in part due to AU Mic being an extremely active star and the lack of full transit coverage plus sufficient out-of-transit baseline. As such, a precise determination of the obliquity for AU\,Mic\,b is not possible in this study and we find a sky-projected spin-orbit angle of $\lambda = 47{^{+26}_{-54}}^{\circ}$. This result is consistent with both the planet's orbit being aligned or highly misaligned with the spin-axis of its host star. Our measurement independently agrees with, but is far less precise than observations carried out on other instruments around the same time that measure a low obliquity orbit for the planet. AU\,Mic is the youngest exoplanetary system for which the projected spin-orbit angle has been measured, making it a key data point in the study of the formation and migration of exoplanets -- particularly given that the system is also host to a bright debris disk., Comment: 15 pages, 6 figures, 3 tables. Published in the Astronomical Journal on 10/09/2021

EarthFinder is a NASA Astrophysics Probe mission concept selected for study as input to the 2020 Astrophysics National Academies Decadal Survey. The EarthFinder concept is based on a dramatic shift in our understanding of how PRV measurements should be made. We propose a new paradigm which brings the high precision, high cadence domain of transit photometry as demonstrated by Kepler and TESS to the challenges of PRV measurements at the cm/s level. This new paradigm takes advantage of: 1) broad wavelength coverage from the UV to NIR which is only possible from space to minimize the effects of stellar activity; 2) extremely compact, highly stable, highly efficient spectrometers (R>150,000) which require the diffraction-limited imaging possible only from space over a broad wavelength range; 3) the revolution in laser-based wavelength standards to ensure cm/s precision over many years; 4) a high cadence observing program which minimizes sampling-induced period aliases; 5) exploiting the absolute flux stability from space for continuum normalization for unprecedented line-by-line analysis not possible from the ground; and 6) focusing on the bright stars which will be the targets of future imaging missions so that EarthFinder can use a ~1.5 m telescope., NASA Probe Mission concept white paper for 2020 Astrophysics National Academies Decadal Survey

Astrophysics spans an enormous range of questions on scales from individual planets to the entire cosmos. To address the richness of 21st century astrophysics requires a corresponding richness of telescopes spanning all bands and all messengers. Much scientific benefit comes from having the multi-wavelength capability available at the same time. Most of these bands,or measurement sensitivities, require space-based missions. Historically, NASA has addressed this need for breadth with a small number of flagship-class missions and a larger number of Explorer missions. While the Explorer program continues to flourish, there is a large gap between Explorers and strategic missions. A fortunate combination of new astrophysics technologies with new, high capacity, low dollar-per-kg to orbit launchers, and new satellite buses allow for cheaper missions with capabilities approaching strategic mission levels. NASA has recognized these developments by calling for Probe-class mission ideas for mission studies, spanning most of the electromagnetic spectrum from GeV gamma-rays to the far infrared, and the new messengers of neutrinos and ultra-high energy cosmic rays. The key insight from the Probes exercise is that order-of-magnitude advances in science performance metrics are possible across the board for initial total cost estimates in the range 500M-1B dollars., Submitted to the Astro2020 Decadal Survey call for Activities, Projects or State of the Profession Consideration (APC). 10 pages

Currently, there are about 4,000 exoplanets that have been discovered and confirmed. Exoplanets, or extrasolar planets, are planets found outside the solar system orbiting other stars. The primary purpose of the Kepler satellite is to detect exoplanets orbiting sun-like stars by detecting dips in brightness (called the transit method); the goal is to detect and characterize earth-sized planets in the Habitable Zone. Researchers involved in following up the K2 mission, a subset of the Kepler mission, perform on-ground experiments to validate the detection of an exoplanet orbiting the star. Using George Mason University’s campus telescope, we have monitored multiple transits of K2 candidate exoplanets and have analyzed the transits of exoplanets EPIC 219388192.01 and EPIC 250001426.01. Here we show that exoplanet EPIC 219388192.01 can likely be confirmed and that while exoplanet EPIC 250001426.01 has a very shallow transit and cannot be confirmed, we can likely rule out that this system has a background eclipsing binary. Once properly formatted and analyzed, the results will be published to the ExoFOP community for further research., Journal of Student-Scientists' Research, Vol 1 (2019)

HISPEC (High-resolution Infrared Spectrograph for Exoplanet Characterization) is a proposed diffraction-limited spectrograph for the W.M. Keck Observatory, and a pathfinder for the MODHIS facility project (Multi-Object Diffraction-limited High-resolution Infrared Spectrograph) on the Thirty Meter Telescope. HISPEC/MODHIS builds on diffraction-limited spectrograph designs which rely on adaptively corrected single-mode fiber feeds. Seeing-limited high-resolution spectrographs, by virtue of the conservation of beam etendue, grow in volume following a D^3 power law (D is the telescope diameter), and are subject to daunting challenges associated with their large size. Diffraction-limited spectrographs fed by single mode fibers are decoupled from the telescope input, and are orders of magnitude more compact and have intrinsically stable line spread functions. Their efficiency is directly proportional to the performance of the adaptive optics (AO) system. AO technologies have matured rapidly over the past two decades and are baselined for future extremely large telescopes. HISPEC/MODHIS will take R>100,000 spectra of a few objects in a 10" field-of-view sampled at the diffraction limit (~10-50 mas), simultaneously from 0.95 to 2.4 microns (y-K). The scientific scope ranges from exoplanet infrared precision radial velocities, spectroscopy of transiting, close-in, and directly imaged exoplanets (atmospheric composition and dynamics, RM effect, spin measurements, Doppler imaging), brown dwarf characterization, stellar physics/chemistry, proto-planetary disk kinematics/composition, Solar system, extragalactic science, and cosmology. HISPEC/MODHIS features a compact, cost-effective design optimized to fully exploit the existing Keck-AO and future TMT-NFIRAOS infrastructures and boost the scientific reach of Keck Observatory and TMT soon after first light.

The fields of Astronomy and Astrophysics are technology limited, where the advent and application of new technologies to astronomy usher in a flood of discoveries altering our understanding of the Universe (e.g., recent cases include LIGO and the GRAVITY instrument at the VLTI). Currently, the field of astronomical spectroscopy is rapidly approaching an impasse: the size and cost of instruments, especially multi-object and integral field spectrographs for extremely large telescopes (ELTs), are pushing the limits of what is feasible, requiring optical components at the very edge of achievable size and performance. For these reasons, astronomers are increasingly looking for innovative solutions like photonic technologies that promote instrument miniaturization and simplification, while providing superior performance. Astronomers have long been aware of the potential of photonic technologies. The goal of this white paper is to draw attention to key photonic technologies and developments over the past two decades and demonstrate there is new momentum in this arena. We outline where the most critical efforts should be focused over the coming decade in order to move towards realizing a fully photonic instrument. A relatively small investment in this technology will advance astronomical photonics to a level where it can reliably be used to solve challenging instrument design limitations. For the benefit of both ground and space borne instruments alike, an endorsement from the National Academy of Sciences decadal survey will ensure that such solutions are set on a path to their full scientific exploitation, which may one day address a broad range of science cases outlined in the KSPs., 11 pages, 3 figures, NAS astro2020 whitepaper

Precise Doppler radial-velocity (RV) instruments will continue to play an essential role in advancing our holistic understanding of exoplanetary systems. The combination of orbital parameters from transit surveys and follow-up RV measurements is vital to unlock mass and density estimates of detected planets, giving us insight into their environment and structure. However, the exoplanet field is reaching a critical juncture: the measurement sensitivity of existing radial-velocity instruments is becoming the limiting factor in further increasing our knowledge. Without improvement in delivered RV measurement precision, we will not be able to provide dynamical mass and density estimates for some of the most exciting (and consequently most challenging) discoveries expected from new transit missions including the Transiting Exoplanet Survey Satellite (TESS) (Plavchan et al. 2015, Ricker et al. 2014). RV precisions at the 10cm/s level are required to fully confirm earth-like analogues, provide masses and measure density to the 1-5% level from these missions. Additionally, this RV capability will also be important to allow for efficient target selection for facilities such as the James Webb Space Telescope (JWST). A promising way forward to achieve this goal is to use single-mode fibers to inject light to a spectrograph. This mitigates many of the error terms facing current generation seeing-limited RV instruments while simultaneously offering the capability of high resolution spectroscopy within a small optical footprint (Schwab et al. 2012, Crepp 2014, Jovanovic et al. 2016a). We discuss the benefits of this technique, its challenges, and the current status of development., A white paper submitted in response to the National Academy of Sciences 2018 Exoplanet Science Strategy solicitation

There is currently a gap in our understanding of wide-orbit planets, which must be filled if we are to understand planet formation and exoplanet habitability. We summarize current and planned exoplanet detection programs using a variety of methods: microlensing (including WFIRST), radial velocities, Gaia astrometry, and direct imaging.