Constraints on the nearby exoplanet <i>ϵ</i> Indi Ab from deep near- and mid-infrared imaging limits

Viswanath, Gayathri; Janson, Markus; Dahlqvist, Carl-Henrik; Samland, M.; Girard, J.; Pathak, Prashant; Kasper, Markus; Feng, Fabo; Meyer, Michael; Boehle, Anna; Quanz, Sascha P.; Jones, H. R. A.; Absil, Olivier; Brandner, W.; Maire, Anne-Lise; Siebenmorgen, R.; Sterzik, M.; Pantin, É.

doi:10.1051/0004-6361/202140730

Cited by 7 publications

(3 citation statements)

References 73 publications

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“…Indi further hosts a brown dwarf binary ( Indi Ba, Bb) in a wide orbit with a projected separation of ∼1500 AU (McCaughrean et al 2004). This system hence provides a benchmark for the study of the formation of gas-giant planets and brown dwarfs (e.g., Pathak et al 2021;Viswanath et al 2021;Chen et al 2022;Šubjak et al 2023). Mathur et al 2017;Hatt et al 2023), and radial-velocity campaigns (red diamonds; see e.g., Arentoft et al 2008;Kjeldsen et al 2008, and references therein).…”

Section: Observations and Data Reductionmentioning

confidence: 99%

Expanding the frontiers of cool-dwarf asteroseismology with ESPRESSO

Campante,

Kjeldsen,

et al. 2024

A&A

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Fuelled by space photometry, asteroseismology is vastly benefitting the study of cool main-sequence stars, which exhibit convection-driven solar-like oscillations. Even so, the tiny oscillation amplitudes in K dwarfs continue to pose a challenge to space-based asteroseismology. A viable alternative is offered by the lower stellar noise over the oscillation timescales in Doppler observations. In this letter we present the definite detection of solar-like oscillations in the bright K5 dwarf epsilon Indi based on time-intensive observations collected with the ESPRESSO spectrograph at the VLT, thus making it the coolest seismic dwarf ever observed. We measured the frequencies of a total of 19 modes of degree $ along with $ max Hz $ and $ Hz $. The peak amplitude of radial modes is $2.6 $, or a mere $ sim 14<!PCT!>$ of the solar value. Measured mode amplitudes are $ sim 2$ times lower than predicted from a nominal $L/M$ scaling relation and favour a scaling closer to $(L/M)^ $ below $ sim K $, carrying important implications for our understanding of the coupling efficiency between pulsations and near-surface convection in K dwarfs. This detection conclusively shows that precise asteroseismology of cool dwarfs is possible down to at least the mid-K regime using next-generation spectrographs on large-aperture telescopes, effectively opening up a new domain in observational asteroseismology.

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Section: Observations and Data Reductionmentioning

confidence: 99%

Expanding the frontiers of cool-dwarf asteroseismology with ESPRESSO

Campante,

Kjeldsen,

et al. 2024

A&A

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“…Thereby, the ε Indi system is highly valuable to put constraints on formation and evolution in the substellar regime (Joergens & Reffert 2014;Feng et al 2019). However, there is disagreement over the age of the system, with estimates spanning a range 0.39-5 Gyr (Cannon 1970;Lachaume et al 1999;Rocha-Pinto et al 2002;Barnes 2007;Kasper et al 2009;King et al 2010;Dieterich et al 2018;Feng et al 2019;Pathak 2021;Viswanath et al 2021;Chen et al 2022), leaving the age to be firmly pinned down.…”

Section: Introductionmentioning

confidence: 99%

Low-amplitude Solar-like Oscillations in the K5 V Star ϵ Indi A

Lundkvist,

Kjeldsen,

Bedding

et al. 2024

ApJ

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We have detected solar-like oscillations in the mid-K-dwarf ϵ Indi A, making it the coolest dwarf to have measured oscillations. The star is noteworthy for harboring a pair of brown dwarf companions and a Jupiter-type planet. We observed ϵ Indi A during two radial velocity campaigns, using the high-resolution spectrographs HARPS (2011) and UVES (2021). Weighting the time series, we computed the power spectra and established the detection of solar-like oscillations with a power excess located at 5265 ± 110 μHz—the highest frequency solar-like oscillations so far measured in any star. The measurement of the center of the power excess allows us to compute a stellar mass of 0.782 ± 0.023 M ⊙ based on scaling relations and a known radius from interferometry. We also determine the amplitude of the peak power and note that there is a slight difference between the two observing campaigns, indicating a varying activity level. Overall, this work confirms that low-amplitude solar-like oscillations can be detected in mid-K-type stars in radial velocity measurements obtained with high-precision spectrographs.

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“…The system utilizes a Raytheon AQUARIUS array with modest quantum efficiency (

\sim

40%) and excess low‐frequency noise (e.g., Hoffmann et al 2014). Despite these limitations, the NEAR project produced interesting results (Kasper et al 2019; Pathak et al 2021; Viswanath et al 2021; Wagner et al 2021), but is no longer available. Another system, NOMIC on the LBTI, also utilizes an AQUARIUS array, with the vast majority of its observations obtained with nulling interferometry (e.g., Ertel et al 2018).…”

Section: Introductionmentioning

confidence: 99%

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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Constraints on the nearby exoplanet ϵ Indi Ab from deep near- and mid-infrared imaging limits

Cited by 7 publications

References 73 publications

Expanding the frontiers of cool-dwarf asteroseismology with ESPRESSO

Expanding the frontiers of cool-dwarf asteroseismology with ESPRESSO

Low-amplitude Solar-like Oscillations in the K5 V Star ϵ Indi A

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

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