Astrophysics – Kavli Institute Pre-Print Publications

Chemical Abundances in the Metal-Poor Globular Cluster ESO 280-SC06: A Formerly Massive, Tidally Disrupted Globular Cluster

Posted by June 18, 2025Chicago

Kavli Affiliate: Alexander P. Ji | First 5 Authors: Sam A. Usman, Alexander P. Ji, Jandrie Rodriguez, Jeffrey D. Simpson, Sarah L. Martell | Summary: We present the first high-resolution abundance study of ESO 280-SC06, one of the least luminous and most metal-poor gravitationally bound Milky Way globular clusters. Using Magellan/MIKE spectroscopy for ten stars, […]

Continue..

Procedures for Constraining Robotic Fiber Positioning for Highly Multiplexed Spectroscopic Surveys: The Case of FPS for SDSS-V

Posted by June 18, 2025Chicago

Kavli Affiliate: Alexander Ji | First 5 Authors: Ilija Medan, Tom Dwelly, Kevin R. Covey, Eleonora Zari, Michael R. Blanton | Summary: One crucial aspect of planning any large scale astronomical survey is constructing an observing strategy that maximizes reduced data quality. This is especially important for surveys that are rather heterogeneous and broad-ranging in […]

Continue..

Acceleration and Collimation of the Two-Sided Jets in the Nearby Low-luminosity Active Galactic Nucleus NGC 4261 (3C 270)

Posted by dbos June 16, 2025June 18, 2025Peking, This Week: Astrophysics

Kavli Affiliate: Luis C. Ho | First 5 Authors: Xi Yan, Lang Cui, Kazuhiro Hada, Sandor Frey, Ru-sen Lu | Summary: We study the acceleration and collimation of the two-sided jets in the nearby low-luminosity active galactic nucleus NGC 4261 (3C 270) using archival multifrequency, multi-epoch Very Long Baseline Array data. By applying multiple analysis […]

Continue..

Laser ablated sub-wavelength structure anti-reflection coating on an alumina lens

Posted by dbos June 16, 2025June 18, 2025This Week: Astrophysics, Tokyo

Kavli Affiliate: Tomotake Matsumura | First 5 Authors: Shaul Hanany, Scott Cray, Samuel Dietterich, Jan Dusing, Calvin Firth | Summary: We used laser ablation to fabricate sub-wavelength structure anti-reflection coating (SWS-ARC) on a 5 cm diameter alumina lens. With an aspect ratio of 2.5, the SWS-ARC are designed to give a broad-band low reflectance response […]

Continue..

Correcting impedance measurements for background parasitics to characterize circuit components in cryogenic environments

Posted by dbos June 13, 2025June 18, 2025Stanford, This Week: Astrophysics

Kavli Affiliate: Noah A. Kurinsky | First 5 Authors: Riley J. Carpenter, Jadyn Anczarski, Ivar Rydstrom, Aviv Simchony, Zoe J. Smith | Summary: Predictable circuit response is a critical prerequisite for accurate electronic measurements. We describe a powerful, yet straightforward, experimental method and analysis model that utilizes an affordable LCR meter in conjunction with an […]

Continue..

Hubble’s Multi-Year Search for Exospheres in the TRAPPIST-1 System Reveals Frequent Microflares

Posted by dbos June 13, 2025June 18, 2025MIT, This Week: Astrophysics

Kavli Affiliate: Sara Seager | First 5 Authors: David Berardo, Julien de Wit, Michael Gillon, Ward S. Howard, Vincent Bourrier | Summary: Ly-$alpha$ observations provide a powerful probe of stellar activity and atmospheric escape in exoplanetary systems. We present here an analysis of 104 HST/STIS orbits monitoring the TRAPPIST-1 system between 2017 and 2022, covering […]

Continue..

Spot-Crossing Variations Confirm a Misaligned Orbit for a Planet Transiting an M Dwarf

Posted by dbos June 13, 2025June 18, 2025MIT, This Week: Astrophysics

Kavli Affiliate: Avi Shporer | First 5 Authors: Patrick Tamburo, Samuel W. Yee, Juliana García-Mejía, David Charbonneau, Allyson Bieryla | Summary: TOI-3884~b is an unusual 6.4~R$_oplus$ planet orbiting an M4 host, whose transits display large and persistent spot-crossing events. We used the textit{Tierras} Observatory to monitor both the long-term photometric variability of TOI-3884 and changes […]

Continue..

Fusion of multi-source precipitation records via coordinate-based generative model

Posted by dbos June 13, 2025June 18, 2025Peking, This Week: Astrophysics

Kavli Affiliate: Li Xin Li | First 5 Authors: Sencan Sun, Congyi Nai, Baoxiang Pan, Wentao Li, Xin Li | Summary: Precipitation remains one of the most challenging climate variables to observe and predict accurately. Existing datasets face intricate trade-offs: gauge observations are relatively trustworthy but sparse, satellites provide global coverage with retrieval uncertainties, and […]

Continue..

The Diversity of Exoplanetary Environments and the Search for Signs of Life Beyond Earth

Posted by dbos June 13, 2025June 18, 2025MIT, This Week: Astrophysics

Kavli Affiliate: Sara Seager | First 5 Authors: Sara Seager, Janusz J. Petkowski, William Bains, , | Summary: Thousands of exoplanets orbit nearby stars, showcasing a remarkable diversity in mass, size, and orbits. With the James Webb Space Telescope now operational, we are observing exoplanet atmospheres and aiming to reach down to small, habitable-zone exoplanets […]

Continue..

Discovery of an HI 21 cm absorption system at z=2.327 with CHIME

Posted by dbos June 12, 2025June 18, 2025MIT, This Week: Astrophysics

Kavli Affiliate: Kiyoshi W. Masui | First 5 Authors: CHIME Collaboration, Mandana Amiri, Arnab Chakraborty, Simon Foreman, Mark Halpern | Summary: We report the detection of a new HI absorption system associated with the radio source NVSS J164725+375218 at a redshift of z=2.327, identified through a blind survey conducted by the Canadian Hydrogen Intensity Mapping […]

Continue..