HYPATIA and STOIC: an active optics system for a large space telescope

Devaney, Nicholas; Reinlein, Claudia; Lange, Nicolas; Goy, Matthias; Goncharov, Alexander V.; Hallibert, Pascal

doi:10.1117/12.2233277

Cited by 7 publications

(2 citation statements)

References 5 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Hence, misalignment of these components and inherent manufacturing caused surface errors must be taken into account as well. Optical aberrations due to those unavoidable effects could be corrected by an active optics correction chain [3]. In this case does not require high dynamic as it is mandatory for the correction of atmospheric turbulence, but an excellent long-term stability in wave front control.…”

Section: Introductionmentioning

confidence: 99%

“…All investigations are performed within the STOIC (Space Telescope Optical Image Corrector) project in response to an ESA invitation to develop an active optics correction chain for future space telescopes. The baseline space telescope (HYPATIA) being considered in this study, is a Ritchey-Chrétien-Cassegrain-telescope with a 4 m monolithic primary mirror [3]. The active mirror has to be designed for high precision and the ability to maintain a stable shape over long periods of time.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Design study for an active metal mirror: sub-system of a correction chain for large UVOIR space telescopes

Goy

Reinlein

Devaney

et al. 2017

International Conference on Space Optics — ICSO 2016

View full text Add to dashboard Cite

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Design study for an active metal mirror: sub-system of a correction chain for large UVOIR space telescopes

Goy

Reinlein

Devaney

et al. 2017

International Conference on Space Optics — ICSO 2016

View full text Add to dashboard Cite

Constraining the radius and atmospheric properties of directly imaged exoplanets through multi-phase observations

Carrión-González

Muñoz²,

Santos³

et al. 2021

A&A

View full text Add to dashboard Cite

Context. The theory of remote sensing shows that observing a planet at multiple phase angles (α) is a powerful strategy to characterize its atmosphere. Here, we study this observing strategy as applied to future disc-integrated direct imaging of exoplanets in reflected starlight. Aims. We analyse how the information contained in reflected-starlight spectra of exoplanets depends on the phase angle and the potential of multi-phase measurements to better constrain the atmospheric properties and the planet radius (Rp). Methods. We simulate spectra (500−900 nm) at α = 37°, 85°, and 123° with a spectral resolution of R ~ 125−225 and signal-to-noise ratio (S∕N) = 10, consistent with the expected capabilities of future direct-imaging space telescopes. Assuming a H2-He atmosphere, we use a seven-parameter model that includes the atmospheric methane abundance (fCH4), the optical properties of a cloud layer and Rp. All these parameters are assumed to be unknown a priori and are explored with a Markov chain Monte Carlo retrieval method. Results. No single-phase observation can robustly identify whether the atmosphere has clouds or not. A single-phase observation at α = 123° and S∕N = 10 can constrain Rp with a maximum error of 35%, regardless of the cloud coverage. We find that combining small (37°) and large (123°) phase angles is a generally effective strategy to break multiple parameter degeneracies. This enables us to determine the presence or absence of a cloud and its main properties, fCH4 and Rp, with higher confidence in all the explored scenarios. Other strategies, such as doubling S∕N to 20 for a single-phase observation or combining small (37°) and moderate (85°) phase angles, fail to achieve this. We show that the improvements in multi-phase retrievals are associated with the shape of the scattering phase function of the cloud aerosols and that the improvement is more modest for isotropically scattering aerosols. We finally discuss that misidentifying the background gas in the retrievals of super-Earth observations leads to systematic underestimation of the absorbing gas abundance. Conclusions. Exoplanets with wide ranges of observable phase angles should be prioritized for atmospheric characterization in reflected starlight.

show abstract

Membrane space telescope: active surface control with radiative adaptive optics

Rabien,

Busoni,

Del Vecchio

et al. 2024

Space Telescopes and Instrumentation 2024: Optical, Infrared, and Millimeter Wave

View full text Add to dashboard Cite

Sensitivity and resolution of space telescopes are directly related to the size of the primary mirror. Enabling such future extremely large space telescopes or even arrays of those will require to drastically reduce the areal weight of the mirror system. Utilizing a thin parabolic polymeric membrane as primary mirror offers the prospect of very low weight and the flexible nature of those membranes allows compactly store them upon launch. Upon deployment the structure is unfolded and the mirror shape restored. Being an extremely thin structure, an active shape correction is required. Utilizing a thermal control of the surface via radiative coupling, localized shape changes are imprinted into the membrane telescope. In this paper we present the modelling and experimental test of the radiative adaptive optics. A detailed modeling of the influence function of the radiative shaping onto the membrane mirror has been carried out. Experimentally we have been radiatively actuated the shape of a prototype mirror in closed loop with a wavefront sensor and proven that we can control the mirrors surface figure to a ~15nm RMS precision.

show abstract

HYPATIA and STOIC: an active optics system for a large space telescope

Cited by 7 publications

References 5 publications

Design study for an active metal mirror: sub-system of a correction chain for large UVOIR space telescopes

Design study for an active metal mirror: sub-system of a correction chain for large UVOIR space telescopes

Constraining the radius and atmospheric properties of directly imaged exoplanets through multi-phase observations

Membrane space telescope: active surface control with radiative adaptive optics

Contact Info

Product

Resources

About