By R. Samadi (LIRA, Observatoire de Paris)
What it does
The HAYDN Noise Estimator (HNE) is a per-star photometric noise model for the proposed HAYDN space mission. For each star it returns the noise-to-signal ratio and the contamination by the light of neighbouring stars. It can be reconfigured for PLATO.
The light of each star spreads over the detector pixels through the point spread function. The star's photometric mask is the set of pixels that collect most of its own light. Light from neighbouring stars that falls in the same mask adds to the light measured and to the noise. The share of the mask's light that is not the target's is what the model returns, star by star, alongside the noise.
The HAYDN Noise Estimator was developed by R. Samadi (LIRA, Observatoire de Paris). No paper describes it and it has no public page.
How I used it
I ran the HNE on Deucalion, a supercomputer, with inputs prepared by the HAYDNsim pipeline, for HAYDN target fields and, in its PLATO configuration, for three PLATO Guest Observer proposals.
The animation
The positions and brightnesses of the stars are Gaia measurements of real members of the globular cluster M13. The masks and the split of each mask's light follow from those positions and brightnesses with the rules of the crowding figure on my HAYDNsim page: one point spread function for every star, and the mask as the pixels collecting most of the target's light.
The pixel size and the point spread function (no instrument's values), the stars' depth along the line of sight, the optics, the colours and the light curves are drawn. Each light curve is a stylised oscillation plus noise sized by the neighbours' share, in arbitrary units. No numbers appear.