8 papers
Analog Electronic Computation of Stellar Structure: Polytropic Benchmarks, Circuit Scaling, and Error-Controlled Verification
Zuhoor Elahi, Wafa Gull, Christopher Sirola
We present an electronic analog-computing framework for static stellar-structure equations and verify it using polytropic Lane-Emden benchmarks with known or high-accuracy referenc…
Evolutionary Period-Change Modeling of Delta Cephei with MESA Tracks
Zuhoor Elahi, Christopher Sirola, Wafa Gull
Cepheid period changes provide a direct evolutionary diagnostic because the pulsation period responds to changes in stellar radius as a star crosses the instability strip. We prese…
Fourier Morphology Diagnostics of Delta Cephei MESA-RSP Light Curves
Zuhoor Elahi, Christopher Sirola, Wafa Gull
Fourier morphology provides a compact test of whether a nonlinear Cepheid model reproduces the observed harmonic content and asymmetric light-curve shape, not only the pulsation pe…
Synthetic Observed-Band Light Curves of Delta Cephei from MESA-RSP Models
Zuhoor Elahi, Christopher Sirola, Wafa Gull
Observed-band light curves provide a stronger test of Cepheid pulsation models than period matching alone, because the measured photometric amplitude depends on the phase-dependent…
Nonlinear MESA-RSP Modeling of Delta Cephei: Period Matching, Amplitude Control, and Model-Acceptance Diagnostics
Zuhoor Elahi, Christopher Sirola, Wafa Gull
Delta Cephei is the prototype classical Cepheid and a useful target for testing whether a one-dimensional nonlinear radial-pulsation workflow can satisfy more than a period constra…
Native-Opacity Sensitivity of a Fixed Delta Cephei MESA-RSP Pulsation Model
Zuhoor Elahi, Christopher Sirola, Wafa Gull
Radiative opacity is one of the central microphysical inputs controlling the thermal response of Cepheid envelopes and the driving or damping of radial pulsations. We present a con…
Semi-Empirical Pulsation Reconstruction of Delta Cephei with Photometry, Radial Velocities, and Temperature Constraints
Zuhoor Elahi, Wafa Gull
We present a semi-empirical reconstruction of the pulsation behavior of the classical Cepheid delta Cephei using observed Johnson-V photometry, HARPS-N radial velocities, and publi…
A Reproducible AAVSO Johnson-V Fourier Template for the Prototype Cepheid Delta Cephei
Zuhoor Elahi, Wafa Gull
We present an empirical Fourier reconstruction of the observed Johnson-V light curve of the prototype Classical Cepheid Delta Cephei. The goal is not to infer a full physical stell…