When Streams Curve Away: a Test of Dark Matter from Extragalactic Stellar Stream Populations

Kavli Affiliate: Lina Necib | Summary:The nature of dark matter sets the shape of galactic halos: collisionless cold dark matter (CDM) predicts triaxial halos, while scattering in self-interacting dark matter (SIDM) rounds them toward sphericity. We show that a large catalog of projected stellar stream tracks can statistically constrain halo shapes, and therefore the particle […]


Continue.. When Streams Curve Away: a Test of Dark Matter from Extragalactic Stellar Stream Populations

Migration and Evolution of giant ExoPlanets (MEEP). III. Twenty-Nine Giant Planets from the TESS Mission

Kavli Affiliate: Avi Shporer | Summary:We present the discovery and characterization of 29 hot and warm Jupiter systems transiting bright ($G < 12.8$) FGK stars using TESS data and ground-based photometry and spectroscopy. Through the use of high angular resolution imaging, we discovered three bound stellar companions, named TOI-3988 B, TOI-6171 B, and TOI-7266 B. […]


Continue.. Migration and Evolution of giant ExoPlanets (MEEP). III. Twenty-Nine Giant Planets from the TESS Mission

VLBI Astrometric Procedure and Performance with CHIME/FRB Outriggers

Kavli Affiliate: Kiyoshi Masui | Summary:Precise localizations of fast radio bursts (FRBs) to specific environments within their host galaxies with very-long-baseline interferometry (VLBI) have provided valuable insights into the nature of their progenitors. To date, such localizations have relied primarily on traditional VLBI facilities, whose observational capabilities limit them to targeted follow-up on a small […]


Continue.. VLBI Astrometric Procedure and Performance with CHIME/FRB Outriggers

Computing gravitational radiation from highly eccentric bound binaries in the small-mass-ratio limit

Kavli Affiliate: Scott A. Hughes | Summary:Precise strong-gravity models describing the evolution of bound compact binary systems provide important information about the gravitational radiation such binaries generate and how they evolve due to the radiation’s backreaction. The limit of very high eccentricity, $e to 1$, is challenging to model: frequency-domain techniques require many harmonics to […]


Continue.. Computing gravitational radiation from highly eccentric bound binaries in the small-mass-ratio limit

Low-loss amorphous dielectric metasurface mirror for precision optical cavities

Kavli Affiliate: Peter Fritschel | Summary:We report the design and experimental realization of a low-loss dielectric metasurface mirror operating at 1064 nm, the primary wavelength of interferometric gravitational-wave detectors. The mirror consists of a single layer of titanium dioxide nanopillars on a glass substrate, achieving high reflectivity via guided-mode resonance. The fabricated mirror has a […]


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Toddlers in Resonance I: low masses and eccentricities of the 17 Myr giant planets HIP 67522 bc from transit timing variations

Kavli Affiliate: Andrew Vanderburg | Summary:Infant ($<$100,Myr) transiting planet systems provide glimpses into the processes that shape the observed mature planet population. Masses for these planets are powerful data points for testing theories of planet formation and evolution. Because young systems tend to be in mean-motion resonances (MMR) and show higher rates of transit timing […]


Continue.. Toddlers in Resonance I: low masses and eccentricities of the 17 Myr giant planets HIP 67522 bc from transit timing variations

Discovery of the Infrared Counterpart of the Rapid Burster with JWST

Kavli Affiliate: Deepto Chakrabarty | Summary:The Rapid Burster (MXB 1730$-$335) is the only known neutron star to produce both Type I and Type II X-ray bursts, making it a key system for understanding accretion physics onto neutron stars. It resides in Liller 1, a dense, metal-rich stellar system whose crowded core and $sim$11 magnitudes of […]


Continue.. Discovery of the Infrared Counterpart of the Rapid Burster with JWST

Galaxy and Halo Assembly Bias in Alternative Dark Matter Models

Kavli Affiliate: Mark Vogelsberger | Summary:The clustering of dark matter halos depends not only on halo mass but also on secondary halo properties, a phenomenon known as halo assembly bias. Coupled with variations in halo occupation, this dependence impacts galaxy clustering, an effect termed galaxy assembly bias. While previous studies have found only weak cosmological […]


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Investigating potential causes for high inferred intrinsic temperatures of warm transiting Neptune and Sub-Neptune planets

Kavli Affiliate: Sara Seager | Summary:Atmospheric characterization of a warm 10-30 Myr old sub-Neptune progenitor (V1298 Tau b) and a $sim$3.4 Gyr old warm super-Neptune (WASP-107b) using JWST have revealed extremely low methane abundance. Atmospheric forward models find higher than expected inferred intrinsic temperatures (450~K and 500~K) — inconsistent with theoretical planet formation and core-envelope […]


Continue.. Investigating potential causes for high inferred intrinsic temperatures of warm transiting Neptune and Sub-Neptune planets

The First Hubble Detection of a Secondary Eclipse from a Rocky Exoplanet: the 5.4-hour planet TOI-2431 b

Kavli Affiliate: Andrew Vanderburg | Summary:We present an HST/WFC3 G141 phase-curve observation of the ultra-short-period rocky planet TOI-2431 b and detect its secondary eclipse in the near infrared. Combined with the TESS optical eclipse, these measurements constrain the planet’s dayside brightness temperature, reflected light contribution, albedo, and heat redistribution. We detect the eclipse in the […]


Continue.. The First Hubble Detection of a Secondary Eclipse from a Rocky Exoplanet: the 5.4-hour planet TOI-2431 b