The Habitable Exoplanet Observatory

Gaudi, B. Scott; Seager, Sara; Mennesson, Bertrand; Kiessling, Alina; Warfield, Keith; Mawet, Dimitri

doi:10.1038/s41550-018-0549-2

Cited by 43 publications

(46 citation statements)

References 10 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Dressing et al (2019) found, in the case of an extremely precise and complete RV survey down to 8 cm/s, that the ini-tial search more time of a direct imaging mission would be reduced by 44%. This initial search is predicted to 71% or 48% of the LUVOIR-A or HabEx mission lifetimes respectively (Roberge & Moustakas 2018;Gaudi et al 2018). Thus a significant reduction in the initial search would greatly boost mission scientific yields by allowing for a focus on planet characterization.…”

Section: Nominalmentioning

confidence: 99%

Joint Radial Velocity and Direct Imaging Planet Yield Calculations. I. Self-consistent Planet Populations

Dulz

Plavchan

Crepp

et al. 2020

ApJ

View full text Add to dashboard Cite

Planet yield calculations may be used to inform the target selection strategy and science operations of space observatories. Forthcoming and proposed NASA missions, such as the Wide-Field Infrared Survey Telescope (WFIRST), the Habitable Exoplanet Imaging Mission (HabEx), and the Large UV/Optical/IR Surveyor (LUVOIR), are expected to be equipped with sensitive coronagraphs and/or starshades. We are developing a suite of numerical simulations to quantify the extent to which ground-based radial velocity (RV) surveys could boost the detection efficiency of direct imaging missions. In this paper, we discuss the first step in the process of estimating planet yields: generating synthetic planetary systems consistent with observed occurrence rates from multiple detection methods. In an attempt to self-consistently populate stars with orbiting planets, it is found that naive extrapolation of occurrence rates (mass, semi-major axis) results in an unrealistically large numberdensity of Neptune-mass planets beyond the ice-line (a 5au), causing dynamic interactions that would destabilize orbits. We impose a stability criterion for multi-planet systems based on mutual Hill radii separation. Considering the influence of compact configurations containing Jovian-mass and Neptune-mass planets results in a marked suppression in the number of terrestrial planets that can exist at large radii. This result has a pronounced impact on planet yield calculations particularly in regions accessible to high-contrast imaging and microlensing. The dynamically compact configurations and occurrence rates that we develop may be incorporated as input into joint RV and direct imaging yield calculations to place meaningful limits on the number of detectable planets with future missions.

show abstract

Section: Nominalmentioning

confidence: 99%

Joint Radial Velocity and Direct Imaging Planet Yield Calculations. I. Self-consistent Planet Populations

Dulz

Plavchan

Crepp

et al. 2020

ApJ

View full text Add to dashboard Cite

show abstract

“…The statistical finding that rocky, temperate exoplanets are common (Dressing & Charbonneau 2015) has received dramatic validation with the discovery of nearby potentially habitable worlds like LHS-1140b, TRAPPIST-1e, TOI-700d, and Kepler-442b (Torres et al 2015;Dittmann et al 2017;Gillon et al 2017;Gilbert et al 2020). Upcoming facilities such as the James Webb Space Telescope, the Extremely Large Telescopes, and the HabEx and LUVOIR mission concepts will have the ability to detect the atmospheres of such worlds and possibly characterize their atmospheric compositions (Rodler & López-Morales 2014;Fujii et al 2018;Lustig-Yaeger et al 2019;LUVOIR Team 2019;Meixner et al 2019;Gaudi et al 2020).…”

Section: Introductionmentioning

confidence: 99%

Photochemistry of Anoxic Abiotic Habitable Planet Atmospheres: Impact of New H₂O Cross Sections

Ranjan

Schwieterman

Harman

et al. 2020

ApJ

Self Cite

View full text Add to dashboard Cite

We present a study of the photochemistry of abiotic habitable planets with anoxic CO 2-N 2 atmospheres. Such worlds are representative of early Earth, Mars, and Venus and analogous exoplanets. Photodissociation of H 2 O controls the atmospheric photochemistry of these worlds through production of reactive OH, which dominates the removal of atmospheric trace gases. The near-UV (NUV; >200 nm) absorption cross sections of H 2 O play an outsized role in OH production; these cross sections were heretofore unmeasured at habitable temperatures (<373 K). We present the first measurements of NUV H 2 O absorption at 292 K and show it to absorb orders of magnitude more than previously assumed. To explore the implications of these new cross sections, we employ a photochemical model; we first intercompare it with two others and resolve past literature disagreement. The enhanced OH production due to these higher cross sections leads to efficient recombination of CO and O 2 , suppressing both by orders of magnitude relative to past predictions and eliminating the low-outgassing "false-positive" scenario for O 2 as a biosignature around solar-type stars. Enhanced [OH] increases rainout of reductants to the surface, relevant to prebiotic chemistry, and may also suppress CH 4 and H 2 ; the latter depends on whether burial of reductants is inhibited on the underlying planet, as is argued for abiotic worlds. While we focus on CO 2-rich worlds, our results are relevant to anoxic planets in general. Overall, our work advances the state of the art of photochemical models by providing crucial new H 2 O cross sections and resolving past disagreement in the literature and suggests that detection of spectrally active trace gases like CO in rocky exoplanet atmospheres may be more challenging than previously considered.

show abstract

“…The KPPs and environments derived by S5 for SRM also apply for the Habitable Exoplanet Observatory (HabEx) mission. 11 The main difference between the two missions that impacts the technology development is in the size of the starshade, with the HabEx starshade being twice as large as the SRM starshade. Thus, a full-scale test article for SRM will be only half-scale for HabEx and therefore of lower fidelity.…”

Section: Technology Gaps To Starshade Missionsmentioning

confidence: 99%

NASA’s starshade technology development activity

Willems

Lisman

2021

J. Astron. Telesc. Instrum. Syst.

View full text Add to dashboard Cite

The Habitable Exoplanet Observatory

Cited by 43 publications

References 10 publications

Joint Radial Velocity and Direct Imaging Planet Yield Calculations. I. Self-consistent Planet Populations

Joint Radial Velocity and Direct Imaging Planet Yield Calculations. I. Self-consistent Planet Populations

Photochemistry of Anoxic Abiotic Habitable Planet Atmospheres: Impact of New H₂O Cross Sections

NASA’s starshade technology development activity

Contact Info

Product

Resources

About

The Habitable Exoplanet Observatory

Cited by 43 publications

References 10 publications

Joint Radial Velocity and Direct Imaging Planet Yield Calculations. I. Self-consistent Planet Populations

Joint Radial Velocity and Direct Imaging Planet Yield Calculations. I. Self-consistent Planet Populations

Photochemistry of Anoxic Abiotic Habitable Planet Atmospheres: Impact of New H2O Cross Sections

NASA’s starshade technology development activity

Contact Info

Product

Resources

About

Photochemistry of Anoxic Abiotic Habitable Planet Atmospheres: Impact of New H₂O Cross Sections