J. Monnier

CHARA Array Observations of the Evolved Components in Symbiotic Star Systems

The nature of the mechanisms that drive mass transfer in symbiotic stars remains an area of active research in stellar astronomy. Constraining the role that both stellar winds and Roche-lobe overflow play in this process is crucial to improving our understanding of these binaries and connecting them to important transi...

Aperture masking interferometry with ELT-METIS

We present sparse-aperture masks for the L/M- and N-band imaging channels of METIS on the ESO ELT. The 6-hole mask forms six ∼4m sub-apertures with Keck-like collecting area and non-redundant baselines for broadband (∼20%) filters. The 12-hole mask forms twelve ∼1.6m sub-apertures, conceptually similar to a VLTI-AT arr...

Starlight Acquisition and Reflection toward Interferometry (STARI) mission

We introduce the NASA-funded mission STARI (STarlight Acquisition and Reflection toward Interferometry), a two-spacecraft technology demonstrator for future long-baseline interferometers. STARI will perform, to our knowledge, the first in-space transfer of starlight between free-flying spacecraft, a critical step towar...

The Hot, Continuum-compact State of the Yellow Hypergiant V509 Cassiopeiae: CHARA Diameters, CO-band Angular-extension Constraints, and Companion Limits

Yellow hypergiants are rare, evolved massive stars generally interpreted as post-red-supergiant objects evolving blueward through or near the dynamically unstable yellow evolutionary void. V509 Cassiopeiae is a remarkable example: its spectroscopically inferred effective temperature increased from approximately 5000 K...

Optical interferometric image reconstruction with learned diffusion priors

Development of quantum technologies for optical/infrared interferometry

Quantum technologies may revolutionize optical interferometry through new means to distribute and preserve electric-field amplitude and phase correlations between widely separated telescopes. After reviewing existing techniques, I survey proposed quantum-sensing and quantum-networking applications and highlight recent...

Dust at the extreme: the CHARA Array polarization model and prospects for polarimetric interferometry

Polarimetric interferometry combines milliarcsecond angular resolution with sensitivity to scattered light and can therefore probe both dust formation around evolved stars and dust survival at the inner rims of planet-forming disks. At optical and near-infrared wavelengths, however, the many oblique reflections in an i...

On-sky demonstration of dual-field interferometry at the CHARA Array

Dual-field interferometry uses a bright reference star for real-time fringe tracking, allowing a second beam combiner to record long coherent integrations on a fainter off-axis science target. At the Center for High Angular Resolution Astronomy (CHARA) Array, we implement this mode using the six-telescope MIRC-X and MY...

Interferometric survey of stellar parameters. Towards homogeneous FGK stars parameters and surface-brightness color relation in the context of PLATO space mission

Estimations of stellar angular diameters can be determined based on the surface brightness-colour relation (SBCR) and photometry. In the context of the PLATO space mission, the SBCR is considered to be an independent empirical alternative for estimating the stellar radii of FGK stars. We implemented a homogeneous appro...