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After about 01:30 in the NASA video NASA's Nancy Grace Roman Space Telescope: Broadening Our Cosmic Horizons the narrator says:

To deepen its study of exoplanets the Roman Space Telescope will house a beyond-state-of-the-art chronograph, that will directly image and analyze Neptune-size planets in orbits slightly larger than Earth’s.

The video shows a diagonal mirror with an articulated phase shifting surface followed by some kind of what I am guessing is a pupil filter.

Questions:

  1. What is this particular coronagraph or its design called, and where can I read in detail about how it works? Please feel free to add a short summary in the answer if so inclined.
  2. What is it about the design that would be considered "beyond-state-of-the-art" or at least merely "state-of-the-art"

screen shot from NASA's Nancy Grace Roman Space Telescope: Broadening Our Cosmic Horizons

screen shot from NASA's Nancy Grace Roman Space Telescope: Broadening Our Cosmic Horizons

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    $\begingroup$ I'm sure Q2 is just journalistic nonsense. If it is beyond state-of-the-art, then it can't be built. It probably just means state-of-the-art. $\endgroup$
    – ProfRob
    May 21, 2020 at 9:26
  • $\begingroup$ @RobJeffries I'd assumed so; answers to What is it about the design that would be considered "merely-state-of-the-art"? would be welcomed as well. $\endgroup$
    – uhoh
    May 21, 2020 at 9:33

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{ell digression} State of the art means that something is based on the highest level of technology available at a given time. "Beyond state of the art" would seem to be journalistic puff. It means that it is based on unavailable technology! Now I would assume the intent here is to indicate that the chronograph is based on new technology that was developed specifically for this application. That is to say, it is not just as good as the current best but it is better than anything else currently available, or perhaps based on technology that we expect to develop over the next few years.

  1. What is this particular coronagraph or its design called, and where can I read in detail about how it works? Please feel free to add a short summary in the answer if so inclined.

So the design of this coronagraph is original. You can read more about the design in general terms on the Nasa web site, and with rather more specific detail below:

Jessica Gersh-Range, A.J. Eldorado Riggs, N. Jeremy Kasdin, "Flight designs and pupil error mitigation for the bowtie shaped pupil coronagraph on the Nancy Grace Roman Space Telescope", J. Astron. Telesc. Instrum. Syst. 8(2) 025003 (31 May 2022) https://doi.org/10.1117/1.JATIS.8.2.025003

The abstract describes some of the innovations in the design of the coronagraph:

The coronagraph instrument [...] include[s] deformable mirrors to correct high-order wavefront errors that would otherwise limit the achievable contrast. The CGI has three baselined interchangeable observing configurations, one of which is a bowtie shaped pupil coronagraph for high-contrast spectroscopy. [The bowtie shaped pupil coronagraph has] a 60-deg mask configuration contributed by the NASA Exoplanet Exploration Program. The shaped pupil mask and Lyot stop for each mask configuration result from an iterative process that maximizes the core throughput subject to constraints on other performance metrics, such as the contrast: a linear program optimizes the shaped pupil mask for a given Lyot stop, and the optimization repeats for various Lyot stops until the highest-throughput combination is identifiable.

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