# naive simulated TPF coronagraph image

A student at Princeton is doing his senior thesis on simulated coronagraph data sets, to use as a testing ground for hypothesis testing of somewhat realistic (low SNR) planet signals.

Fomalhaut is the target star for the case study. For its distance of 7.61 pc, 1 AU and 5 AU projected separations correspond to 131.4 mas and 657.0 mas, respectively. For 8-meter telescope observing at 550 nm, $\lambda/D$ = 14.2 mas, so maximum angular separations are 9.27 $\lambda/D$ and 46.33 $\lambda/D$. Periastron for the inclined, circular 5 AU orbit is $\cos(66^{\circ})\times 46.3 \lambda/D = 18.85 \lambda/D$.
I handed off a Matlab Fourier propagation model of a concentric ring (spiderweb) coronagraph to my student. This design has a working angle range $6 - 60 \lambda/D$ to frame the system nicely. Also note that 1 AU projected separation at 1.34 pc distance of alpha Cen corresponds to $1/1.339 / 0.0142 = 52.6 \lambda/D$.

This design surpasses $10^{-10}$ contrast for the ideal wavefront, so of course it’s fun to throw in the canonical Earth-like dot, shown below to the right of the star (whose PSF “saturates” the flux scale).