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Creators/Authors contains: "Agabi, Abdelkrim"

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  1. Abstract We present Cryoscope, a new 50 deg2field-of-view, 1.2 m aperture,Kdarksurvey telescope to be located at Dome C, Antarctica. Cryoscope has an innovative optical–thermal design wherein the entire telescope is cryogenically cooled. Cryoscope also explores new detector technology to cost-effectively tile the full focal plane. Leveraging the dark Antarctic sky and minimizing telescope thermal emission, Cryoscope achieves unprecedented deep, wide, fast, and red observations, matching and exceeding volumetric survey speeds from the Ultraviolet Explorer, Vera Rubin Observatory, Nancy Grace Roman Space Telescope, SPHEREx, and NEO Surveyor. By providing coverage beyond wavelengths of 2μm, we aim to create the most comprehensive dynamic movie of the most obscured reaches of the Universe. Cryoscope will be a dedicated discovery engine for electromagnetic emission from coalescing compact binaries, Earth-like exoplanets orbiting cold stars, and multiple facets of time-domain, stellar, and solar system science. In this paper, we describe the scientific drivers and technical innovations for this new discovery engine operating in theKdarkpassband, why we choose to deploy it in Antarctica, and the status of a fifth-scale prototype designed as a Pathfinder to retire technological risks prior to full-scale implementation. We plan to deploy the Cryoscope Pathfinder to Dome C in 2026 December and the full-scale telescope by 2030. 
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    Free, publicly-accessible full text available June 1, 2026
  2. TheβPictoris system is the closest known stellar system with directly detected gas giant planets, an edge-on circumstellar disc, and evidence of falling sublimating bodies and transiting exocomets. The inner planet,βPictoris c, has also been indirectly detected with radial velocity (RV) measurements. The star is a knownδScuti pulsator, and the long-term stability of these pulsations opens up the possibility of indirectly detecting the gas giant planets through time delays of the pulsations due to a varying light travel time. We search for phase shifts in theδScuti pulsations consistent with the known planetsβPictoris b and c and carry out an analysis of the stellar pulsations ofβPictoris over a multi-year timescale. We used photometric data collected by the BRITE-Constellation, bRing, ASTEP, and TESS to derive a list of the strongest and most significantδScuti pulsations. We carried out an analysis with the open-source python package maelstrom to study the stability of the pulsation modes ofβPictoris in order to determine the long-term trends in the observed pulsations. We did not detect the expected signal forβPictoris b orβPictoris c. The expected time delay is 6 s forβPictoris c and 24 s forβPictoris b. With simulations, we determined that the photometric noise in all the combined data sets cannot reach the sensitivity needed to detect the expected timing drifts. An analysis of the pulsational modes ofβPictoris using maelstrom showed that the modes themselves drift on the timescale of a year, fundamentally limiting our ability to detect exoplanets aroundβPictoris via pulsation timing. 
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