arXiv subjects

Jason T. Wright

Publications and source records attributed to Jason T. Wright.

At least 37 records · Page 2Linked to original sources

arXiv2025

The NEID Earth Twin Survey. III. Survey Performance After Three Years on Sky

The NEID Earth Twin Survey (NETS) has been delivering a rich set of precise radial velocity (RV) measurements for 41 bright, nearby main sequence stars. Here, we describe the status of the survey after three years on sky and we present the full set of RV measurements and accompanying stellar activity indicators. We discuss intermediate survey diagnostics, including calibration of the known RV zero point offset introduced following the Contreras fire in 2022 and the identification of an undiagnosed and previously unknown zero point offset in 2021. An analysis of our data set using RVSearch demonstrates that for these target stars, NEID is independently sensitive to nearly all known planets with periods shorter than the NETS observing baseline. We also highlight a number of newly detected RV signals, which present exciting opportunities for future investigations.

astro-ph.EP↗

arXiv2025

Technosignature Searches of Interstellar Objects

With the discovery of the third confirmed interstellar object (ISO), 3I/ATLAS, we have entered a new phase in the exploration of these long-predicted objects. Though confirmed discovery of ISOs is quite recent, their utility as targets in the search for technosignatures (historically known as the Search for Extraterrestrial Intelligence -- SETI) has been discussed for many decades. With the upcoming NSF-DOE Vera C. Rubin Observatory's Legacy Survey of Space and Time (LSST), the discovery and tracking of such objects is expected to become routine, and thus so must our examination of these objects for possible technosignatures. Here we review the literature surrounding ISOs as targets for technosignatures, which provides a well-developed motivation for such exploration. We outline four broad classes of technosignatures that are well suited for ISO follow-up, including the type of data needed and the best timing for study. Given the limitations in the current understanding of ISOs, we show that care must be taken in identifying technosignatures based primarily on comparison to objects in the Solar System. We therefore provide a roadmap for careful and consistent study of the population of ISOs in the hope of identifying technosignatures.

astro-ph.IM↗

arXiv2025

Detecting Extraterrestrial Civilizations That Employ an Earth-level Deep Space Network

A major aspect of the search for extraterrestrial intelligence (SETI) involves searching for electromagnetic transmissions from extraterrestrial sources, often using our own transmissions as a guide. Previous studies have suggested that humanity's most consistently detectable technosignatures were transmissions from our deep-space networks and interplanetary radar. In this study, we analyze NASA Deep Space Network logs to explore what strategies for selecting SETI targets and scheduling observations would enhance the chances of detecting such networks. Analyzing Deep Space Network uplink transmission logs over the last 20 yr, we find that these emissions were predominantly directed along the ecliptic plane, towards or directly away from the Sun, and towards other planets. The average duty cycle within the Earth Transit Zone is 20 times higher than that across all ecliptic latitudes. In the case of Mars, we find a species that is able to observe the Solar System for radio emission during an Earth-Mars conjunction in the past 20 yr would have had a 77% chance of observing during one of our transmissions, a $4\times10^5$-fold increase over intercepting our Deep Space Network transmission versus a random observer at a random time. These findings quantify how SETI searches might benefit from prioritizing edge-on exoplanet systems and aligning observation windows with exoplanetary conjunctions or planet-planet occultations because they significantly improve the likelihood of intercepting transmissions from any civilizations employing deep-space networks similar to our own.

astro-ph.IM↗

arXiv2025

Time-resolved p-mode oscillations for subgiant HD 142091 with NEID at WIYN

Detections of Earth-analog planets in radial velocity observations are limited by stellar astrophysical variability occurring on a variety of timescales. Current state-of-the-art methods to disentangle potential planet signals from intrinsic stellar signals assume that stellar signals introduce asymmetries to the line profiles that can therefore be separated from the pure translational Doppler shifts of planets. Here, we examine this assumption using a time series of resolved stellar p-mode oscillations in HD 142091 ($κ$ CrB), as observed on a single night with the NEID spectrograph at 2-minute cadence and with 25 cm/s precision. As an evolved subgiant star, this target has p-mode oscillations that are larger in amplitude (4-8 m/s) and occur on longer timescales (80 min.) than those of typical Sun-like stars of RV surveys, magnifying their corresponding effects on the stellar spectral profile. We show that for HD 142091, p-mode oscillations manifest primarily as pure Doppler shifts in the average line profile -- measured by the cross-correlation function (CCF) -- with "shape-driven" CCF variations as a higher-order effect. Specifically, we find that the amplitude of the shift varies across the CCF bisector, with 10% larger oscillation amplitudes closer to the core of the CCF, and 25% smaller oscillation amplitudes for bisector velocities derived near the wings; we attribute this trend to larger oscillation velocities higher in the stellar atmosphere. Using a line-by-line analysis, we verify that a similar trend is seen as a function of average line depth, with deeper lines showing larger oscillation amplitudes. Finally, we find no evidence that p-mode oscillations have a chromatic dependence across the NEID bandpass beyond that due to intrinsic line depth differences across the spectrum.

astro-ph.SR↗

arXiv2025

A Disintegrating Rocky World Shrouded in Dust and Gas: Mid-IR Observations of K2-22b using JWST

The disintegrating ultra-short period rocky exoplanet K2-22b periodically emits dusty clouds in a dynamically chaotic process resulting in a variable transit depth from 0-1.3%. The effluents that sublimate off the surface and condense out in space are probably representative of the formerly interior layers convectively transported to the molten surface. Transmission spectroscopy of these transiting clouds reveal spectral fingerprints of the interior composition of this rocky world. We used JWST's Mid-Infrared Instrument (MIRI) as a low-resolution slitless spectrograph to observe four predicted transit windows for K2-22b. For each observation, we extracted a transmission spectrum over the spectral range of 4.4-11.8 $μ$m. Over the spectral range of 4.4-8 $μ$m, where the spectral precision is highest, we detect one transit at high significance and two at low significance. While the S/N of the spectrum limits our ability to draw firm conclusions, we find that the data: 1) disfavor featureless, iron-dominated core material, 2) are consistent with some form of magnesium silicate minerals, likely from mantle material, and 3) show a distinct and unexpected feature at $\sim$5 $μ$m. The unexpected feature, also seen weakly in the low-significance transits, is consistent with an unknown gaseous absorber, possibly NO and/or CO$_2$. These findings warrant further study to improve the constraints on the composition of this disintegrating rocky world.

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arXiv2025

The NEID Earth Twin Survey. II. Dynamical Masses in Seven High-acceleration Star Systems

We present a set of companion dynamical masses and orbital parameters of seven star systems from the NEID Earth Twin Survey with significant absolute astrometric accelerations between the epochs of Hipparcos and Gaia. These include four binary star systems (HD 68017 AB, 61 Cygni AB, HD 24496 AB, and HD 4614 AB) and three planetary systems (HD 217107, HD 190360, and HD 154345). Our analyses incorporate a long baseline of RVs that includes over 1100 previously unpublished measurements from NEID and MINERVA, extending the overall RV baseline for each system by $\approx$2.5 years, as well as relative astrometry for the stellar binary systems where the positions of both stars are well-measured. In each case, the combination of astrometry and RVs constrains the three-dimensional acceleration of the host star and enables precise dynamical masses. We publish true masses for three planets whose measurements were previously entangled with their inclinations, four stellar masses with $\lesssim$1% relative precision, and improved orbital solutions for all seven systems, including the first for HD 24496 AB. These solutions not only agree with previous estimates, but also improve their fidelity. We also explore each system for evidence of periodic signals in the residuals around our best-fit models, and discuss the potential that the three planetary systems have for being directly imaged. With dynamical mass estimates and reliable orbit ephemerides, these seven star systems represent promising benchmarks for future stellar and planetary characterization efforts, and are amenable for further improvement with the upcoming release of Gaia epoch astrometry.

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arXiv2025

Three-dimensional Orbit and Dynamical Masses of GJ 105 AC

The precision of stellar models is higher than the precision at which we are able to measure the masses of most stars, with the notable exception of binaries where we can determine dynamical masses of the component stars. In addition to well-measured stellar properties, the ideal benchmark star is far enough from its companion that its properties are indistinguishable from an otherwise identical single star. Currently, there are a handful of stars with precise ($\pm$3 %), model-independent mass measurements that are "effectively single" and for which we can obtain clean spectra (i.e. spectra that are not blended with a close companion). In this paper, we introduce GJ 105 AC as the newest members of this exclusive population. We present an updated orbital analysis for the long-period K3+M7 binary GJ 105 AC. We jointly analyze radial velocity (RV) and relative astrometry data, including new RVs from the Miniature Exoplanet Radial Velocity Array (MINERVA) that capture the full periapsis passage and the RV minimum of the $76.0 \pm 1.3$ yr orbit for the first time. We derive precise dynamical masses of $M_1 = 0.78 \pm 0.02\, \mathrm{M}_\odot$ and $M_2 = 0.098 \pm 0.002\, \mathrm{M}_\odot$. We find that of all stars with similarly precise masses (~2%), GJ 105 AC stands out as having the widest on-sky separation after $α$ Centauri AB, making it one of the most easily accessible to spectroscopy, as well as the the second-widest true separation, ensuring that its members are truly "effectively single" in terms of their evolution.

astro-ph.SR↗

arXiv2025

Astrometry and Precise Radial Velocities Yield a Complete Orbital Solution for the Nearby Eccentric Brown Dwarf LHS 1610 b

The LHS 1610 system consists of a nearby ($d=9.7$ pc) M5 dwarf hosting a candidate brown dwarf companion in a $10.6$ day, eccentric ($e \sim 0.37$) orbit. We confirm this brown dwarf designation and estimate its mass ($ 49.5_{-3.5}^{+4.3}$ $M_{\text{Jup}} $) and inclination ($ 114.5^\circ$ $_{-10.0}^{+7.4}$) by combining discovery radial velocities (RVs) from TRES and new RVs from the Habitable-zone Planet Finder with the available Gaia astrometric two-body solution. We highlight a discrepancy between the measurement of the eccentricity from the Gaia two-body solution ($e=0.52 \pm 0.03$) and the RV-only solution ($e=0.3702\pm0.0003$). We discuss possible reasons for this discrepancy, which can be further probed when the Gaia astrometric time series becomes available as part of Gaia DR4. As a nearby mid-M star hosting a massive short-period companion with a well-characterized orbit, LHS 1610 b is a promising target to look for evidence of sub-Alfvénic interactions and/or auroral emission at optical and radio wavelengths. LHS 1610 has a flare rate ($0.28\pm 0.07$ flares/day) on the higher-end for its rotation period ($84 \pm 8$ days), similar to other mid-M dwarf systems such as Proxima Cen and YZ Ceti that have recent radio detections compatible with star-planet interactions. While available TESS photometry is insufficient to determine an orbital phase-dependence of the flares, our complete orbital characterization of this system makes it attractive to probe star-companion interactions with additional photometric and radio observations.

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arXiv2025

A reassessment of the "hard-steps" model for the evolution of intelligent life

According to the "hard-steps" model, the origin of humanity required "successful passage through a number of intermediate steps" (so-called "hard" or "critical" steps) that were intrinsically improbable with respect to the total time available for biological evolution on Earth. This model similarly predicts that technological life analogous to human life on Earth is "exceedingly rare" in the universe. Here, we critically reevaluate the core assumptions of the hard-steps model in light of recent advances in the Earth and life sciences. Specifically, we advance a potential alternative model where there are no hard steps, and evolutionary novelties (or singularities) required for human origins can be explained via mechanisms outside of intrinsic improbability. Furthermore, if Earth's surface environment was initially inhospitable not only to human life, but also to certain key intermediate steps in human evolution (e.g., the origin of eukaryotic cells, multicellular animals), then the "delay" in the appearance of humans can be best explained through the sequential opening of new global environmental windows of habitability over Earth history, with humanity arising relatively quickly once the right conditions were established. In this co-evolutionary (or geobiological) scenario, humans did not evolve "early" or "late" with respect to the total lifespan of the biosphere, but "on time."

q-bio.PE↗

arXiv2025

Earth Detecting Earth: At what distance could Earth's constellation of technosignatures be detected with present-day technology?

The field of the Search for Extraterrestrial Intelligence (SETI) searches for ``technosignatures'' that could provide the first detection of life beyond Earth through the technology that an extraterrestrial intelligence (ETI) may have created. Any given SETI survey, if no technosignatures are detected, should set upper limits based on the kinds of technosignatures it should have been able to detect; the sensitivity of many SETI searches requires that their target sources (e.g., Dyson spheres or Kardashev II/III level radio transmitters) emit with power far exceeding the kinds of technology humans have developed. In this paper, we instead turn our gaze Earthward, minimizing the axis of extrapolation by only considering transmission and detection methods commensurate with an Earth-2024 level. We evaluate the maximum distance of detectability for various present-day Earth technosignatures -- radio transmissions, atmospheric technosignatures, optical and infrared signatures, and objects in space or on planetary surfaces -- using only present-day Earth instruments, providing one of the first fully cross-wavelength comparisons of the growing toolbox of SETI techniques. In this framework, we find that Earth's space-detectable signatures span 13 orders of magnitude in detectability, with intermittent, celestially-targeted radio transmission (i.e., planetary radar) beating out its nearest non-radio competitor by a factor of $10^3$ in detection distance. This work highlights the growing range of ways that exoplanet technosignatures may be expressed, the growing complexity and visibility of the human impact upon our planet, and the continued importance of the radio frequencies in SETI.

astro-ph.IM↗

arXiv2024

Jitter Across 15 Years: Leveraging Precise Photometry from Kepler and TESS to Extract Exoplanets from Radial Velocity Time Series

Stellar activity contamination of radial velocity (RV) data is one of the top challenges plaguing the field of extreme precision RV (EPRV) science. Previous work has shown that photometry can be very effective at removing such signals from RV data, especially stellar activity caused by rotating star spots and plage.The exact utility of photometry for removing RV activity contamination, and the best way to apply it, is not well known. We present a combination photometric and RV study of eight Kepler/K2 FGK stars with known stellar variability. We use NEID RVs acquired simultaneously with TESS photometry, and we perform injection recovery tests to quantify the efficacy of recent TESS photometry versus archival Kepler/K2 photometry for removing stellar variability from RVs. We additionally experiment with different TESS sectors when training our models in order to quantify the real benefit of simultaneously acquired RVs and photometry. We conclude that Kepler photometry typically performs better than TESS at removing noise from RV data when it is available, likely due to longer baseline and precision. In contrast, for targets with available K2 photometry, especially those most active, and with high precision ($σ_{NEID}$ $<$ 1 m s$^{-1}$) NEID RVs, TESS may be the more informative dataset. However, contrary to expectations, we have found that training on simultaneous photometry does not always achieve the best results.

astro-ph.EP↗

arXiv2024

Origins of Super Jupiters: TOI-2145b Has a Moderately Eccentric and Nearly Aligned Orbit

Super Jupiters are giant planets with several Jupiter masses. It remains an open question whether these planets originate with such high masses or grow through collisions. Previous work demonstrates that warm super Jupiters tend to have more eccentric orbits compared to regular-mass warm Jupiters. This correlation between mass and eccentricity may indicate that planet-planet interactions significantly influence the warm giant planet demographics. Here we conducted a detailed characterization of a warm super Jupiter, TOI-2145b. This analysis utilized previous observations from TESS and Keck/HIRES, enhanced by new Rossiter-McLaughlin effect data from the NEID spectrometer on the 3.5 m WIYN Telescope. TOI-2145b is a $5.68^{+0.37}_{-0.34} M_{\rm Jup}$ planet on a moderate eccentricity ($e = 0.214^{+0.014}_{-0.014}$), 10.26-day orbit, orbiting an evolved A-star. We constrain the projected stellar obliquity to be $λ= 6.8^{+2.9}_{-3.8}$$^\circ$ from two NEID observations. Our $N$-body simulations suggest that the formation of super Jupiter TOI-2145b could involve either of two scenarios: a high initial mass or growth via collisions. On a population level, however, the collision scenario can better describe the mass-eccentricity distribution of observed warm Jupiters.

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arXiv2024

SETI in 2022

In this third installment of SETI in 20xx, we very briefly and subjectively review developments in SETI in 2022. Our primary focus is 80 papers and books published or made public in 2022, which we sort into six broad categories: results from actual searches, new search methods and instrumentation, target and frequency selection, the development of technosignatures, theory of ETIs, and social aspects of SETI.

astro-ph.IM↗

arXiv2024

Strong Nongravitational Accelerations and the Potential for Misidentification of Near-Earth Objects

Nongravitational accelerations in the absence of observed activity have recently been identified on NEOs, opening the question of the prevalence of anisotropic mass-loss in the near-Earth environment. Motivated by the necessity of nongravitational accelerations to identify 2010 VL$_{65}$ and 2021 UA$_{12}$ as a single object, we investigate the problem of linking separate apparitions in the presence of nongravitational perturbations. We find that nongravitational accelerations on the order of $10^{-9}$ au/d$^2$ can lead to a change in plane-of-sky positions of $\sim10^3$ arcsec between apparitions. Moreover, we inject synthetic tracklets of hypothetical nongravitationally-accelerating NEOs into the Minor Planet Center orbit identification algorithms. We find that at large nongravitational accelerations ($|A_i|\geq10^{-8}$ au/d$^2$) these algorithms fail to link a significant fraction of these tracklets. We further show that if orbits can be determined for both apparitions, the tracklets will be linked regardless of nongravitational accelerations, although they may be linked to multiple objects. In order to aid in the identification and linkage of nongravitationally accelerating objects, we propose and test a new methodology to search for unlinked pairs. When applied to the current census of NEOs, we recover the previously identified case but identify no new linkages. We conclude that current linking algorithms are generally robust to nongravitational accelerations, but objects with large nongravitational accelerations may potentially be missed. While current algorithms are well-positioned for the anticipated increase in the census population from future survey missions, it may be possible to find objects with large nongravitational accelerations hidden in isolated tracklet pairs.

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arXiv2024

HZ_evolution: A Package to Calculate Habitable Histories

We present HZ_evolution, a Python package to characterize the habitable histories of exoplanets. Given inputs of a planet's current effective flux and host star properties, HZ_evolution calculates its instellation history, the evolution of the star's Habitable Zone, and the duration the planet spends inside or outside the Habitable Zone.

astro-ph.EP↗

arXiv2024

The NEID Earth Twin Survey. I. Confirmation of a 31-day planet orbiting HD 86728

With close to three years of observations in hand, the NEID Earth Twin Survey (NETS) is starting to unearth new astrophysical signals for a curated sample of bright, radial velocity (RV)-quiet stars. We present the discovery of the first NETS exoplanet, HD 86728 b, a $m_p\sin i = 9.16^{+0.55}_{-0.56}\ \rm{M}_\oplus$ planet on a circular, $P=31.1503^{+0.0062}_{-0.0066}$ d orbit, thereby confirming a candidate signal identified by Hirsch et al. (2021). We confirm the planetary origin of the detected signal, which has a semi-amplitude of just $K=1.91^{+0.11}_{-0.12}$ m s$^{-1}$, via careful analysis of the NEID RVs and spectral activity indicators, and we constrain the mass and orbit via fits to NEID and archival RV measurements. The host star is intrinsically quiet at the $\sim1$ m s$^{-1}$ level, with the majority of this variability likely stemming from short-timescale granulation. HD 86728 b is among the small fraction of exoplanets with similar masses and periods that have no known planetary siblings.

astro-ph.EP↗

arXiv2024

A Radio Technosignature Search of TRAPPIST-1 with the Allen Telescope Array

Planet-planet occultations (PPOs) occur when one exoplanet occults another exoplanet in the same system as seen from the Earth's vantage point. PPOs may provide a unique opportunity to observe radio "spillover" from extraterrestrial intelligences' (ETIs) radio transmissions or radar being transmitted from the further exoplanet towards the nearer one for the purposes of communication or scientific exploration. Planetary systems with many tightly packed, low-inclination planets, such as TRAPPIST-1, are predicted to have frequent PPOs. Here, the narrowband technosignature search code turboSETI was used in combination with the newly developed NbeamAnalysis filtering pipeline to analyze 28 hours of beamformed data taken with the Allen Telescope Array (ATA) during late October and early November 2022, from 0.9--9.3~GHz, targeting TRAPPIST-1. During this observing window, 7 possible PPO events were predicted using the NbodyGradient code. The filtering pipeline reduced the original list of 25 million candidate signals down to 6 million by rejecting signals that were not sky-localized and, from these, identified a final list of 11127 candidate signals above a power law cutoff designed to segregate signals by their attenuation and morphological similarity between beams. All signals were plotted for visual inspection, 2264 of which were found to occur during PPO windows. We report no detection of signals of non-human origin, with upper limits calculated for each PPO event exceeding EIRPs of 2.17--13.3 TW for minimally drifting signals and 40.8--421 TW in the maximally drifting case. This work constitutes the longest single-target radio SETI search of TRAPPIST-1 to date.

astro-ph.EP↗

arXiv2024

Data-Driven Modeling of Telluric Features and Stellar Variability with StellarSpectraObservationFitting.jl

A significant barrier to achieving the radial velocity (RV) measurement accuracy and precision required to characterize terrestrial mass exoplanets is the existence of time-variable features in the measured spectra, from both telluric absorption and stellar variability, which affect measured line shapes and can cause apparent RV shifts. Reaching the desired accuracy using traditional techniques often requires avoiding lines contaminated by stellar variability and/or changing tellurics, and thus discarding a large fraction of the spectrum, lowering precision. New data-driven methods can help achieve extremely precise and accurate RVs by enabling the use of a larger fraction of the available data. While there exist methods for modeling telluric features or the stellar variability individually, there is a need for additional tools that are capable of modeling them simultaneously at the spectral level. Here we present StellarSpectraObservationFitting.jl (SSOF), a Julia package for measuring Doppler shifts and creating data-driven models (with fast, physically-motivated Gaussian Process regularization) for the time-variable spectral features for both the telluric transmission and stellar spectrum, while accounting for the wavelength-dependent instrumental line-spread function. We demonstrate SSOF's state-of-the-art performance on data from the NEID RV spectrograph on the WIYN 3.5m Telescope for multiple stars. We show SSOF's, ability to accurately identify and characterize spectral variability and provide $\sim$2-6x smaller photon-limited errors over the NEID CCF-based pipeline and match the performance of SERVAL, a leading template-based pipeline, using only observed EPRV spectra.

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