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All sourcesNASA NTRSDOE OSTI
DOE OSTI2020

On the Chemical Abundance of HR 8799 and the Planet c

Comparing chemical abundances of a planet and the host star reveals the origin and formation pathway of the planet. Stellar abundance is measured with high-resolution spectroscopy. Planet abundance, on the other hand, is usually inferred from low-resolution data. For directly imaged exoplanets, the data are available from a slew of high-contrast imaging/spectroscopy instruments. Here, we study the chemical abundance of HR 8799 and its planet c. We measure stellar abundance using LBT/PEPSI (R = 120,000) and archival HARPS data: stellar [C/H], [O/H], and C/O are 0.11 ± 0.12, 0.12 ± 0.14, and 0.54{sub −0.09}{sup +0.12}, all consistent with solar values. We conduct atmospheric retrieval using newly obtained Subaru/CHARIS data together with archival Gemini/GPI and Keck/OSIRIS data. We model the planet spectrum with petitRADTRANS and conduct retrieval using PyMultiNest. Retrieved planetary abundance can vary by ∼0.5 dex, from sub-stellar to stellar C and O abundances. The variation depends on whether strong priors are chosen to ensure a reasonable planet mass. Moreover, comparison with previous works also reveals inconsistency in abundance measurements. We discuss potential issues that can cause the inconsistency, e.g., systematics in individual data sets and different assumptions in the physics and chemistry in retrieval. We conclude that no robust retrieval can be obtained unless the issues are fully resolved.

79 ASTRONOMY AND ASTROPHYSICS↗
DOE OSTI2020

High-resolution Spectra of Earth-like Planets Orbiting Red Giant Host Stars

In the near future we will have ground- and space-based telescopes that are designed to observe and characterize Earth-like planets. While attention is focused on exoplanets orbiting main-sequence stars, more than 150 exoplanets have already been detected orbiting red giants, opening the intriguing question of what rocky worlds orbiting in the habitable zone (HZ) of red giants would be like and how to characterize them. We present a high-resolution spectral database of reflection and emission spectra for nominal Earth-like planets orbiting in the red giant HZ from the visible to infrared (0.4–20 μm) for planets orbiting at the Earth-equivalent distance. We also show the change of such planetary spectra through the evolution of their red giant hosts. While the luminosity of the host increases the contrast ratio between star and planet, the increased orbital distance of the HZ for red giant hosts relaxes the light suppression requirements close to the star, which could make such planets interesting targets to characterize and search for signs of life, if new coronagraph designs with higher suppression at larger orbital separations could be developed. We assess the feasibility of characterizing atmospheric features including biosignatures for such planets with the proposed mission concept Large UV/Optical/IR Surveyor (LUVOIR).

79 ASTRONOMY AND ASTROPHYSICS↗
DOE OSTI2020

KMT-2019-BLG-0842Lb: A Cold Planet below the Uranus/Sun Mass Ratio

We report the discovery of a cold planet with a very low planet/host mass ratio of q = (4.09 ± 0.27) × 10 -5 , which is similar to the ratio of Uranus/Sun (q = 4.37 × 10 -5 ) in the solar system. The Bayesian estimates for the host mass, planet mass, system distance, and planet–host projected separation are M {sub host} = 0.76 ± 0.40M ⊙ , M planet = 10.3 ± 5.5M ⊕ , D L = 3.3 ± 1.3 kpc, and a ⊥ = 3.3 ± 1.4 au, respectively. The consistency of the color and brightness expected from the estimated lens mass and distance with those of the blend suggests the possibility that the most blended light comes from the planet host, and this hypothesis can be established if high-resolution images are taken during the next (2020) bulge season. We discuss the importance of conducting optimized photometry and aggressive follow-up observations for moderately or very high magnification events to maximize the detection rate of planets with very low mass ratios.

79 ASTRONOMY AND ASTROPHYSICS↗
DOE OSTI2021

A Collage of Small Planets from the Lick–Carnegie Exoplanet Survey: Exploring the Super-Earth and Sub-Neptune Mass Regime

Analysis of new precision radial velocity (RV) measurements from the Lick Automated Planet Finder and Keck HIRES has yielded the discovery of three new exoplanet candidates orbiting the nearby stars HD 190007 and HD 216520. We also report new velocities from the APF and the Planet Finder Spectrograph and updated orbital fits for the known exoplanet host stars GJ 686 and HD 180617. Of the newly discovered planets, HD 190007 b has a period of P = 11.72 days, an RV semiamplitude of K = 5.64 ± 0.55 m s{sup −1}, a minimum mass of M {sub pl} = 16.46 ± 1.66 M {sub ⊕}, and orbits the slightly metal-rich, active K4V star HD 190007. For HD 216520 b, we find P = 35.45 days, K = 2.28 ± 0.20 m s{sup −1}, and M {sub pl} = 10.26 ± 0.99 M {sub ⊕}, while for HD 216520 c, P = 154.43 days, K = 1.29 ± 0.22 m s{sup −1}, and M {sub pl} = 9.44 ± 1.63 M {sub ⊕}. Both planets orbit the slightly metal-poor, inactive K0V star HD 216520. Our updated best-fit models for HD 180617 b and GJ 686 b are in good agreement with the published results. For HD 180617 b, we obtain P = 105.91 days and M {sub pl} = 12.214 ± 1.05 M {sub ⊕}. For GJ 686 b, we find P = 15.53 days and M {sub pl} = 6.624 ± 0.432 M {sub ⊕}. Using an injection-recovery exercise, we find that HD 190007 b and HD 216520 b are unlikely to have additional planets with masses and orbital periods within a factor of 2, in marked contrast to ∼85% of planets in this mass and period range discovered by Kepler.

79 ASTRONOMY AND ASTROPHYSICS↗
DOE OSTI2021

TOI-1231 b: A Temperate, Neptune-sized Planet Transiting the Nearby M3 Dwarf NLTT 24399

We report the discovery of a transiting, temperate, Neptune-sized exoplanet orbiting the nearby (d = 27.5 pc), M3V star TOI-1231 (NLTT 24399, L 248-27, 2MASS J10265947-5228099). The planet was detected using photometric data from the Transiting Exoplanet Survey Satellite and followed up with observations from the Las Cumbres Observatory and the Antarctica Search for Transiting ExoPlanets program. Combining the photometric data sets, we find that the newly discovered planet has a radius of 3.65{sub −0.15}{sup +0.16} R{sub ⊕} and an orbital period of 24.246 days. Radial velocity measurements obtained with the Planet Finder Spectrograph on the Magellan Clay telescope confirm the existence of the planet and lead to a mass measurement of 15.5 ± 3.3 M {sub ⊕}. With an equilibrium temperature of just 330 K, TOI-1231 b is one of the coolest small planets accessible for atmospheric studies thus far, and its host star’s bright near-infrared brightness (J = 8.88, K {sub s} = 8.07) makes it an exciting target for the Hubble Space Telescope and the James Webb Space Telescope. Future atmospheric observations would enable the first comparative planetology efforts in the 250–350 K temperature regime via comparisons with K2-18 b. Furthermore, TOI-1231's high systemic radial velocity (70.5 km s{sup −1}) may allow for the detection of low-velocity hydrogen atoms escaping the planet by Doppler, shifting the H i Lyα stellar emission away from the geocoronal and interstellar medium absorption features.

47 OTHER INSTRUMENTATION↗
DOE OSTI2021

Planets Across Space and Time (PAST). II. Catalog and Analyses of the LAMOST–Gaia–Kepler Stellar Kinematic Properties

The Kepler telescope has discovered over 4000 planets (candidates) by searching ~200,000 stars over a wide range of distance (order of kpc) in our Galaxy. Characterizing the kinematic properties (e.g., Galactic component membership and kinematic age) of these Kepler targets (including the planet candidate hosts) is the first step toward studying Kepler planets in the Galactic context, which will reveal fresh insights into planet formation and evolution. In this paper, the second part of the Planets Across the Space and Time (PAST) series, by combining the data from the Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST) and Gaia and then applying the revised kinematic methods from PAST I, we present a catalog of kinematic properties (i.e., Galactic positions, velocities, and the relative membership probabilities among the thin disk, thick disk, Hercules stream, and the halo) as well as other basic stellar parameters for 35,835 Kepler stars. Further analyses of the LAMOST–Gaia–Kepler catalog demonstrate that our derived kinematic age reveals the expected stellar activity-age trend. Furthermore, we find that the fraction of thin (thick) disk stars increases (decreases) with the transiting planet multiplicity (N {sub p} = 0, 1, 2 and 3+) and the kinematic age decreases with N {sub p}, which could be a consequence of the dynamical evolution of planetary architecture with age. The LAMOST–Gaia–Kepler catalog will be useful for future studies on the correlations between the exoplanet distributions and the stellar Galactic environments as well as ages.

47 OTHER INSTRUMENTATION↗
DOE OSTI2021

Systematic KMTNet Planetary Anomaly Search. I. OGLE-2019-BLG-1053Lb, a Buried Terrestrial Planet

In order to exhume the buried signatures of “missing planetary caustics” in Korea Microlensing Telescope Network (KMTNet) data, we conducted a systematic anomaly search of the residuals from point-source point-lens fits, based on a modified version of the KMTNet EventFinder algorithm. This search revealed the lowest-mass-ratio planetary caustic to date in the microlensing event OGLE-2019-BLG-1053, for which the planetary signal had not been noticed before. The planetary system has a planet–host mass ratio of q = (1.25 ± 0.13) × 10{sup -5}. A Bayesian analysis yielded estimates of the mass of the host star, M{sub host}=0.61{sub -0.24}{sup +0.29} M{sub ⊙}, the mass of its planet, M{sub planet}=2.48{sub -0.98}{sup +1.19} M{sub ⊕}, the projected planet–host separation, a{sub ⊥}=3.4{sub -0.5}{sup +0.5} au, and the lens distance, D{sub L}=6.8{sub -0.9}{sup +0.6} kpc. The discovery of this very-low-mass-ratio planet illustrates the utility of our method and opens a new window for a large and homogeneous sample to study the microlensing planet–host mass ratio function down to q ~ 10{sup -5}.

47 OTHER INSTRUMENTATION↗
DOE OSTI2021

TOI-1749: an M dwarf with a Trio of Planets including a Near-resonant Pair

We report the discovery of one super-Earth- (TOI-1749b) and two sub-Neptune-sized planets (TOI-1749c and TOI-1749d) transiting an early M dwarf at a distance of 100 pc, which were first identified as planetary candidates using data from the TESS photometric survey. We have followed up this system from the ground by means of multiband transit photometry, adaptive optics imaging, and low-resolution spectroscopy, from which we have validated the planetary nature of the candidates. We find that TOI-1749b, c, and d have orbital periods of 2.39, 4.49, and 9.05 days, and radii of 1.4, 2.1, and 2.5 R {sub ⊕}, respectively. We also place 95% confidence upper limits on the masses of 57, 14, and 15 M {sub ⊕} for TOI-1749b, c, and d, respectively, from transit timing variations. The periods, sizes, and tentative masses of these planets are in line with a scenario in which all three planets initially had a hydrogen envelope on top of a rocky core, and only the envelope of the innermost planet has been stripped away by photoevaporation and/or core-powered mass-loss mechanisms. These planets are similar to other planetary trios found around M dwarfs, such as TOI-175b,c,d and TOI-270b,c,d, in the sense that the outer pair has a period ratio within 1% of 2. Such a characteristic orbital configuration, in which an additional planet is located interior to a near 2:1 period-ratio pair, is relatively rare around FGK dwarfs.

47 OTHER INSTRUMENTATION↗
DOE OSTI2021

TOI-532b: The Habitable-zone Planet Finder confirms a Large Super Neptune in the Neptune Desert orbiting a metal-rich M-dwarf host

We confirm the planetary nature of TOI-532b, using a combination of precise near-infrared radial velocities with the Habitable-zone Planet Finder, Transiting Exoplanet Survey Satellite (TESS) light curves, ground-based photometric follow up, and high-contrast imaging. TOI-532 is a faint (J ~ 11.5) metal-rich M dwarf with T{sub eff} = 3957 ± 69 K and [Fe/H] = 0.38 ± 0.04; it hosts a transiting gaseous planet with a period of ~2.3 days. Joint fitting of the radial velocities with the TESS and ground-based transits reveal a planet with radius of 5.82 ± 0.19 R {sub ⊕}, and a mass of 61.5{sub -9.3}{sup +9.7} M {sub ⊕}. TOI-532b is the largest and most massive super Neptune detected around an M dwarf with both mass and radius measurements, and it bridges the gap between the Neptune-sized planets and the heavier Jovian planets known to orbit M dwarfs. It also follows the previously noted trend between gas giants and host-star metallicity for M-dwarf planets. In addition, it is situated at the edge of the Neptune desert in the Radius–Insolation plane, helping place constraints on the mechanisms responsible for sculpting this region of planetary parameter space.

36 MATERIALS SCIENCE↗
DOE OSTI2022

Kinematic Evidence for an Embedded Planet in the IM Lupi Disk

Abstract We test the hypothesis that an embedded giant planet in the IM Lupi protostellar disk can produce velocity kinks seen in CO line observations as well as the spiral arms seen in scattered light and continuum emission. We inject planets into 3D hydrodynamics simulations of IM Lupi, generating synthetic observations using Monte Carlo radiative transfer. We find that an embedded planet of 2–3 M Jup can reproduce non-Keplerian velocity perturbations, or “kinks”, in the 12 CO J = 2–1 channel maps. Such a planet can also explain the spiral arms seen in 1.25 mm dust continuum emission and 1.6 μ m scattered-light images. We show that the wake of the planet can be traced in the observed peak velocity map, which appears to closely follow the morphology expected from our simulations and from analytic models of planet–disk interaction.

79 ASTRONOMY AND ASTROPHYSICS↗
NASA NTRS2007

Terrestrial Planet Finder Interferometer Science Working Group Report

Over the past two years, the focus of the project for the interferometric version of the Terrestrial Planet Finder(TPF-I) has been on the development of the scientific rational for the mission, the assessment of TPF-I architectures, the laboratory demonstration of key technologies, and the development of a detailed technology roadmap. The Science Working Group (SWG), in conjunction with European colleagues working on the European Space Agency's (ESA's) Darwin project, has reaffirmed the goals of TPF-I as part of a broad vision for the detection and characterization of Earth-like planets orbiting nearby stars and for the search for life on those planets. The SWG also helped to assess the performance of different interferometric configurations for TPF-I/Darwin. Building on earlier SWG reports, this document restates the scientific case for TPF-I, assesses suitable target stars and relevant wavelengths for observation, discusses dramatic new capabilities for general astrophysical observations, and summarizes how Spitzer has improved our knowledge of the incidence of zodiacal emission on the search for planets. This document discusses in some detail on laboratory advances in interferometric nulling and formation flying. Laboratory experiments have now achieved stable narrow- and broad-band nulling the levels of 10-6 and 2.0x10-5, respectively. A testbed has demonstrated formation flying using two realistic spacecraft mockups. With a suitably funded program of technology development, as summarized herein and described in more detail in the Technology Plan for the Terrestrial Planet Finder Interferometer (2005), the National Aeronautics and Space Administration (NASA) and ESA would be able to start within the coming decade a full-scale TPF-I/Darwin mission capable of finding Earths orbiting more than 150 nearby stars, or a scaled back interferometer capable of studying more than 30 stars. Finding evidence for life on just one of those planets would revolutionize our understanding of our place in the cosmos.

interferometers↗
NASA NTRS2007

Astrometric Planet Searches with SIM PlanetQuest

SIM will search for planets with masses as small as the Earth's orbiting in the habitable zones' around more than 100 of the stars and could discover many dozen if Earth-like planets are common. With a planned 'Deep Survey' of 100-450 stars (depending on desired mass sensitivity) SIM will search for terrestrial planets around all of the candidate target stars for future direct detection missions such as Terrestrial Planet Finder and Darwin, SIM's 'Broad Survey' of 2010 stars will characterize single and multiple-planet systems around a wide variety of stellar types, including many now inaccessible with the radial velocity technique. In particular, SIM will search for planets around young stars providing insights into how planetary systems are born and evolve with time.

formation solar system↗
NASA NTRS2011

Modeling Kepler Transit Light Curves as False Positives: Rejection of Blend Scenarios for Kepler-9, and Validation of Kepler-9 d, a Super-Earth-Size Planet in a Multiple System

Light curves from the Kepler Mission contain valuable information on the nature of the phenomena producing the transit-like signals. To assist in exploring the possibility that they are due to an astrophysical false positive we describe a procedure (BLENDER) to model the photometry in terms of a blend rather than a planet orbiting a star. A blend may consist of a background or foreground eclipsing binary (or star-planet pair) whose eclipses are attenuated by the light of the candidate and possibly other stars within the photometric aperture. We apply BLENDER to the case of Kepler-9 (KIC 3323887), a target harboring two previously confirmed Saturn-size planets (Kepler-9 b and Kepler-9 c) showing transit timing variations, and an additional shallower signal with a 1.59 day period suggesting the presence of a super-Earth-size planet. Using BLENDER together with constraints from other follow-up observations we are able to rule out all blends for the two deeper signals and provide independent validation of their planetary nature. For the shallower signal, we rule out a large fraction of the false positives that might mimic the transits. The false alarm rate for remaining blends depends in part (and inversely) on the unknown frequency of small-size planets. Based on several realistic estimates of this frequency, we conclude with very high confidence that this small signal is due to a super-Earth-size planet (Kepler-9 d) in a multiple system, rather than a false positive. The radius is determined to be 1.64(exp)(sub-14),R, and current spectroscopic observations are as yet insufficient to establish its mass.

PLANETARY SYSTEMS↗
NASA NTRS2013

Direct Imaging Search for Extrasolar Planets in the Pleiades

We carried out an imaging survey for extrasolar planets around stars in the Pleiades (125 Myr, 135 pc) in the H and K(sub S) bands using HiCIAO combined with adaptive optics, AO188, on the Subaru telescope. We found 13 companion candidates fainter than 14.5 mag in the H band around 9 stars. Five of these 13 were confirmed to be background stars by measurement of their proper motion. One was not found in the second epoch observation, and thus was not a background or companion object. One had multi-epoch images, but the precision of its proper motion was not sufficient to conclude whether it was a background object. Four other candidates are waiting for second-epoch observations to determine their proper motion. Finally, the remaining two were confirmed to be 60 M(sub J) brown dwarf companions orbiting around HD 23514 (G0) and HII 1348 (K5), respectively, as had been reported in previous studies. In our observations, the average detection limit for a point source was 20.3 mag in the H band beyond 1.′′ 5 from the central star. On the basis of this detection limit, we calculated the detection efficiency to be 90% for a planet with 6 to 12 Jovian masses and a semi-major axis of 50–1000 AU. For this reason we extrapolated the distribution of the planet mass and the semi-major axis derived from radial velocity observations, and adopted the planet evolution model Baraffe et al. (2003, A&A, 402, 701). Since there was no detection of a planet, we estimated the frequency of such planets to be less than 17.9% (2 sigma) around one star of the Pleiades cluster.

extrasolar planets↗
NASA NTRS2014

Herschel/PACS Photometry of Transiting-Planet Host Stars with Candidate Warm Debris Disks

Dust in debris disks is produced by colliding or evaporating planetesimals, which are remnants of the planet formation process. Warm dust disks, known by their emission at less than or equal to 24 micrometer, are rare (4% of FGK main sequence stars) and especially interesting because they trace material in the region likely to host terrestrial planets, where the dust has a very short dynamical lifetime. Statistical analyses of the source counts of excesses as found with the mid-IR Wide Field Infrared Survey Explorer (WISE) suggest that warm-dust candidates found for the Kepler transiting-planet host-star candidates can be explained by extragalactic or galactic background emission aligned by chance with the target stars. These statistical analyses do not exclude the possibility that a given WISE excess could be due to a transient dust population associated with the target. Here we report Herschel/PACS 100 and 160 micron follow-up observations of a sample of Kepler and non-Kepler transiting-planet candidates' host stars, with candidate WISE warm debris disks, aimed at detecting a possible cold debris disk in any one of them. No clear detections were found in any one of the objects at either wavelength. Our upper limits confirm that most objects in the sample do not have a massive debris disk like that in beta Pic. We also show that the planet-hosting star WASP-33 does not have a debris disk comparable to the one around eta Crv. Although the data cannot be used to rule out rare warm disks around the Kepler planet-hosting candidates, the lack of detections and the characteristics of neighboring emission found at far-IR wavelengths support an earlier result suggesting that most of the WISE-selected IR excesses around Kepler candidate host stars are likely due to either chance alignment with background IR-bright galaxies and/or to interstellar emission.

Wide Field Infrared Survey Explorer (WISE)↗
NASA NTRS2016

On the Composition of Young, Directly Imaged Giant Planets

The past decade has seen significant progress on the direct detection and characterization of young, self-luminous giant planets at wide orbital separations from their host stars. Some of these planets show evidence for disequilibrium processes like transport-induced quenching in their atmospheres; photochemistry may also be important, despite the typically large orbital distances. Disequilibrium chemical processes such as these can alter the expected composition, spectral behavior, thermal structure, and cooling history of the planets, and can potentially confuse determinations of bulk elemental ratios, which provide important insights into planet-formation mechanisms. Using a thermo/photochemical kinetics and transport model, we investigate the extent to which disequilibrium chemical processes affect the composition and spectra of directly imaged giant exoplanets. Results for specific "young Jupiters" such as HR 8799 b and c and 51 Eri b are presented, as are general trends as a function of planetary effective temperature, surface gravity, incident ultraviolet flux, and strength of deep atmospheric convection. We find that quenching is very important on young Jupiters, leading to CO/CH4 and N2/NH3 ratios much greater than; and H2O mixing ratios a factor of a few less than chemical equilibrium predictions. Photochemistry can also be important on such planets, with CO2 and HCN being key photochemical products. Carbon dioxide becomes a particularly major constituent when stratospheric temperatures are low and recycling of water following H2O photolysis becomes stifled. Young Jupiters with effective temperatures less than 700 degrees Kelvin are in a particularly interesting photochemical regime that differs from both transiting hot Jupiters and our own solar-system giant planets.

photochemistry↗
NASA NTRS2019

Climates of Warm Earth-like Planets. III. Fractional Habitability from a Water Cycle Perspective

The habitable fraction of a planet's surface is important for the detectability of surface biosignatures. The extent and distribution of habitable areas are influenced by external parameters that control the planet's climate, atmospheric circulation, and hydrological cycle. We explore these issues using the ROCKE-3D general circulation model, focusing on terrestrial water fluxes and thus the potential for the existence of complex life on land. Habitability is examined as a function of insolation and planet rotation for an Earth-like world with zero obliquity and eccentricity orbiting the Sun. We assess fractional habitability using an aridity index that measures the net supply of water to the land. Earth-like planets become "superhabitable" (a larger habitable surface area than Earth) as insolation and day-length increase because their climates become more equable, reminiscent of past warm periods on Earth when complex life was abundant and widespread. The most slowly rotating, most highly irradiated planets, though, occupy a hydrological regime unlike any on Earth, with extremely warm, humid conditions at high latitudes but little rain and subsurface water storage. Clouds increasingly obscure the surface as insolation increases, but visibility improves for modest increases in rotation period. Thus, moderately slowly rotating rocky planets with insolation near or somewhat greater than modern Earth's appear to be promising targets for surface characterization by a future direct imaging mission.

Exoplanet atmospheric variability↗
NASA NTRS2022

Four Sub-Jovian-Mass Planets Detected by High-Cadence Microlensing Surveys

Aims. With the aim of finding short-term planetary signals, we investigated the data collected from current high-cadence microlensing surveys. Methods. From this investigation, we found four planetary systems with low planet-to-host mass ratios, including OGLE-2017-BLG- 1691L, KMT-2021-BLG-0320L, KMT-2021-BLG-1303L, and KMT-2021-BLG-1554L. Despite the short durations, ranging from a few hours to a couple of days, the planetary signals were clearly detected by the combined data of the lensing surveys. We found that three of the planetary systems have mass ratios on the order of 10−4 and the other has a mass ratio that is slightly greater than 10−3. Results. The estimated masses indicate that all discovered planets have sub-Jovian masses. The planet masses of KMT-2021-BLG- 0320Lb, KMT-2021-BLG-1303Lb, and KMT-2021-BLG-1554Lb correspond to ∼0.10, ∼0.38, and ∼0.12 times the mass of the Jupiter, and the mass of OGLE-2017-BLG-1691Lb corresponds to that of the Uranus. The estimated mass of the planet host KMT-2021-BLG- 1554L, M host ∼ 0.08 M ⊙ , corresponds to the boundary between a star and a brown dwarf. Besides this system, the host stars of the other planetary systems are low-mass stars with masses in the range of ∼[0.3–0.6] M ⊙ . The discoveries of the planets fully demonstrate the capability of the current high-cadence microlensing surveys in detecting low-mass planets.

planets and satellites: detection↗