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| Paper: |
Very High Precision Astrometry for Exoplanets and Dark Matter with the Habitable Worlds Observatory |
| Monograph: |
11, HWO25 Proceedings Part II: Mission Framework, Technology, and Broader Contributions |
| Page: |
65 |
| Authors: |
Fabien Malbet, Jerome Amiaux, Florence Ardellier-Desages, Renaud Goullioud |
| DOI: |
10.26624/HUHD5756 |
| Abstract: |
Astrometry, one of the oldest branches of astronomy, has been
revolutionized by missions like Hipparcos and especially Gaia, which mapped
billions of stars with extraordinary precision. However, challenges
such as detecting Earth-like exoplanets in nearby habitable zones
and probing the influence of dark matter in galactic environments
require sub-microarcsecond accuracy.
With a 6–8 meter large-aperture telescope operating across at
visible wavelengths, the Habitable Worlds Observatory by NASA can
combine astrometry and direct imaging to detect rocky exoplanets
within 10 parsecs and study their atmospheres. We consider here the
scientific requirements and present a concept for a dedicated
astrometric instrument on HWO. It is capable to produce
diffraction-limited images of large fields, achieving a point-spread
function (PSF) precision of 20 milliarcseconds. Equipped with a
detector calibration system, HWO can perform high precision
astrometry, and, detect and measure the orbit of Earth-mass planets
in the habitable zone of Nearby Solar-type stars. HWO can
dramatically improve current constraints on the self-interaction
cross section of heavy dark matter particles (WIMPs) and on the
masses of ultra-high dark matter particles, through the study
of stellar motions in galactic environments.
The visible channel of the instrument features a large CMOS-based
focal plane with stitched pixel arrays, enabling a large field of
view. The ‘‘Detector Calibration Unit” system uses interferometric
laser fringes to calibrate pixel positions. Using differential
astrometry and pointed observations with a stable telescope design
enables extended integration times, enhancing sensitivity to
sub-microarcsecond precision for detecting exoplanets and studying
dark matter through stellar motion. |
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