Imaging low-mass planets within the habitable zone of α Centauri

Wagner, Kevin; Boehle, Anna; Pathak, Prashant; Kasper, Markus; Arsenault, Robin; Jakob, Gerd; Käufl, U.; Leveratto, Serban; Maire, Anne-Lise; Pantin, E.; Siebenmorgen, R.; Zins, G.; Absil, Olivier; Ageorges, N.; Apai, Dániel; Carlotti, Alexis; Choquet, Élodie; Delacroix, Christian; Dohlen, Kjetil; Duhoux, Philippe; Forsberg, Pontus; Fuenteseca, Eloy; Gutruf, S.; Guyon, Olivier; Huby, Elsa; Kampf, Dirk; Karlsson, Mikael; Kervella, P.; Kirchbauer, Jean-Paul; Klupar, Pete; Kolb, Johann; Mawet, Dimitri; N’Diaye, Mamadou; Xivry, Gilles Orban de; Quanz, Sascha P.; Reutlinger, Arnd; Ruane, Garreth; Riquelme, M.; Soenke, C.; Sterzik, M. F.; Vigan, A.; Zeeuw, Tim de

doi:10.1038/s41467-021-21176-6

Cited by 48 publications

(63 citation statements)

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“…In each case we assume 2σ limits as described in the text. The red line and star denote the SMA and range of masses corresponding to the candidate planet detected by the VLT NEAR project (Kasper et al 2019;Wagner et al 2021). and could lead to the identification of a 25 M ⊕ planet with a 2 au orbital semimajor axis (Figure 9).…”

Section: Prospects For Planet Detection Based On Differential Astrometrymentioning

confidence: 99%

“…The mid-infrared direct imaging project NEAR (Kasper et al 2019;Wagner et al 2021) has tentatively identified a candidate planet associated with α Cen A. While instrument artifacts cannot yet be ruled out, they find an object at 1.1 au from α Cen A with a range of possible radii between 3.3 and 7 M ⊕ .…”

Section: Prospects For Planet Detection Based On Differential Astrometrymentioning

confidence: 99%

“…Alpha Cen A's luminosity of 1.5 L e (Thévenin et al 2002) puts the center of its habitable zone (HZ) at a physical separation of 1.2 au, which corresponds to an angular separation of 0 9. Alpha Cen A is thus an attractive target for direct imaging searches for planets using ground-or space-based observatories (Kasper et al 2019;Beichman et al 2020;Wagner et al 2021). Current precision radial velocity (PRV) observations (Zhao et al 2018) constrain the mass of any planet to be ( )…”

Section: Introductionmentioning

confidence: 99%

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Precision Millimeter Astrometry of the α Centauri AB System

Akeson

Beichman

Kervella³

et al. 2021

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Alpha Centauri A is the closest solar-type star to the Sun and offers the best opportunity to find and ultimately to characterize an Earth-sized planet located in its habitable zone. Here, we describe initial results from an Atacama Large Millimeter/submillimeter Array (ALMA) program to search for planets in the α Cen AB system using differential astrometry at millimeter wavelengths. Our initial results include new absolute astrometric measurements of the proper motion, orbital motion and parallax of the α Cen system. These lead to an improved knowledge of the physical properties of both α Cen A and B. Our estimates of ALMA's relative astrometric precision suggest that we will ultimately be sensitive to planets of a few tens of Earth mass in orbits from 1 to 3 au, where stable orbits are thought to exist.

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Section: Prospects For Planet Detection Based On Differential Astrometrymentioning

confidence: 99%

Section: Prospects For Planet Detection Based On Differential Astrometrymentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Precision Millimeter Astrometry of the α Centauri AB System

Akeson

Beichman

Kervella³

et al. 2021

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“…The ostensible detection of an Earth-mass exoplanet orbiting α-Cen B (Dumusque et al 2012) was later found to be an artifact of the observational technique (Rajpaul et al 2016). However, owing to its immediate proximity to our Solar System, α-CenA/B continues to generate interest in the search for Earth-like planets (Zhao et al 2018;Kasper et al 2019;Beichman et al 2020;Wagner et al 2021;Akeson et al 2021). Radial-velocity measurements put the following detection limits on the masses of planets in the habitable zones of A and B, respectively: M A sin i < 53M ⊕ and M B sin i < 8.4M ⊕ (Zhao et al 2018).…”

Section: Introductionmentioning

confidence: 99%

“…Radial-velocity measurements put the following detection limits on the masses of planets in the habitable zones of A and B, respectively: M A sin i < 53M ⊕ and M B sin i < 8.4M ⊕ (Zhao et al 2018). Recent attempts to directly image low-mass planets in α-CenA/B with the NEAR experiment at the Very Large Telescope (VLT) observatory have ruled out Jupiter-sized planets (Wagner et al 2021). A candidate signal that may be consistent with an exoplanet of R ∼ 3.3 − 7R ⊕ around α-Cen A awaits confirmation (Wagner et al 2021).…”

Section: Introductionmentioning

confidence: 99%

A model Earth-sized planet in the habitable zone of $α$ Centauri A/B

Wang,

Lineweaver,

Quanz

et al. 2021

Preprint

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The bulk chemical composition and interior structure of rocky exoplanets are of fundamental importance to understanding their long-term evolution and potential habitability. Observations of the chemical compositions of the solar system rocky bodies and of other planetary systems have increasingly shown a concordant picture that the chemical composition of rocky planets reflects that of their host stars for refractory elements, whereas this expression breaks down for volatiles. This behavior is explained by devolatilization during planetary formation and early evolution. Here, we apply a devolatilization model calibrated with the solar system bodies to the chemical composition of our nearest Sun-like stars -α Centauri A and B -to estimate the bulk composition of any habitable-zone rocky planet in this binary system ("α-Cen-Earth"). Through further modeling of likely planetary interiors and early atmospheres, we find that compared to Earth, such a planet is expected to have (i) a reduced (primitive) mantle that is similarly dominated by silicates albeit enriched in carbon-bearing species (graphite/diamond); (ii) a slightly larger iron core, with a core mass fraction of 38.4 +4.7 −5.1 wt% (cf. Earth's 32.5 ± 0.3 wt%); (iii) an equivalent water-storage capacity; and (iv) a CO 2 -CH 4 -H 2 O-dominated early atmosphere that resembles that of Archean Earth. Further taking into account its ∼ 25% lower intrinsic radiogenic heating from long-lived radionuclides, an ancient α-Cen-Earth (∼ 1.5-2.5 Gyr older than Earth) is expected

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Evaluating the GeoSnap 13‐μ$$ \mu $$m cutoff HgCdTe detector for mid‐IR ground‐based astronomy

et al. 2023

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New mid‐infrared HgCdTe (MCT) detector arrays developed in collaboration with Teledyne Imaging Sensors (TIS) have paved the way for improved 10‐m sensors for space‐ and ground‐based observatories. Building on the successful development of longwave HAWAII‐2RGs for space missions such as NEO Surveyor, we characterize the first 13‐m GeoSnap detector manufactured to overcome the challenges of high‐background rates inherent in ground‐based mid‐IR astronomy. This test device merges the longwave HgCdTe photosensitive material with Teledyne's GeoSnap‐18 (18‐m pixel) focal plane module, which is equipped with a capacitive transimpedance amplifier (CTIA) readout circuit paired with an onboard 14‐bit analog‐to‐digital converter (ADC). The final assembly yields a mid‐IR detector with high QE, fast readout (>85 Hz), large well depth (>1.2 million electrons), and linear readout. Longwave GeoSnap arrays would ideally be deployed on existing ground‐based telescopes as well as the next generation of extremely large telescopes. While employing advanced adaptive optics (AO) along with state‐of‐the‐art diffraction suppression techniques, instruments utilizing these detectors could attain background‐ and diffraction‐limited imaging at inner working angles <10 /D, providing improved contrast‐limited performance compared with JWST MIRI while operating at comparable wavelengths. We describe the performance characteristics of the 13‐m GeoSnap array operating between 38 45 K, including quantum efficiency, well depth, linearity, gain, dark current, and frequency‐dependent () noise profile.

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Imaging low-mass planets within the habitable zone of α Centauri

Cited by 48 publications

References 49 publications

Precision Millimeter Astrometry of the α Centauri AB System

Precision Millimeter Astrometry of the α Centauri AB System

A model Earth-sized planet in the habitable zone of $α$ Centauri A/B

Evaluating the GeoSnap 13‐μ$$ \mu $$m cutoff HgCdTe detector for mid‐IR ground‐based astronomy

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