Exoplanets, -moons, -comets

PoET: The Paranal Solar ESPRESSO Telescope

By Keith Cowing
Status Report
astro-ph.IM
May 17, 2025
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PoET: The Paranal Solar ESPRESSO Telescope
Left: Image of the Sun with Earth superimposed on the same scale. Upper-right: Radial-velocity time-series of the Sun (green points), obtained with the HARPS-N solar telescope (Dumusque et al., 2021), when compared with the expected signature of an Earth-like planet orbiting a Sun-like star (red curve). Lower-right: simulated spurious signature of an absorption spectrum of an atmosphere-less Earth-like planet centered in the sodium line (blue curve), as caused by unaccounted center-to-limb variations. The observed signal has a magnitude level similar to the expected absorption signature of the atmosphere of an Earth-like planet. These plots illustrate the challenges for the detection and characterisation of Earth-like planets orbiting other suns. Image sources: NASA SDO and ESO/M. Kornmesser

The detection and characterisation of other “Earths”, orbiting other suns, is a bold objective of present-day astrophysics.

However, this quest is severely challenged by astrophysical “noise” from the host stars, whose signatures distort the observed spectra. Motivated by this problem, we are building a dedicated facility, the Paranal solar ESPRESSO Telescope (PoET).

PoET will collect solar light and channel it into the ESPRESSO spectrograph, allowing us to use the Sun as a proxy to unambiguously identify and understand the sources of relevant variability in solar-type stars.

Concept of PoET (left) and scheme of the main telescope (right) with the positioning of the two frontends and the SHABAR seeing measurement device. — astro-ph.SR

Nuno C. Santos, Alexandre Cabral, Inês Leite, Alain Smette, Manuel Abreu, David Alves, Jorge H.C. Martins, Manuel Monteiro, André Silva, Bachar Wehbe, Jimmy Arancibia, Gerardo Ávila, Stephane Brillant, César Cárdenas, Ricardo Clara, Ricardo Gafeira, Daniel Gaytan, Christophe Lovis, Nicolas Miranda, Pedro Moreno, António Oliveira, Angel Otarola, Francesco Pepe, Pascual Rojas, Ricardo Schmutzer, Danuta Sosnowska, Pierre van der Heyden, Khaled Al Moulla, Vardan Adibekyan, Alba Barka, Susana C. C. Barros, Pedro Branco, Eduardo Cristo, Yuri Damasceno, Olivier Demangeon, William Dethier, João P. Faria, João Gomes da Silva, Eduardo Gonçalves, Jennifer P. Lucero, José Rodrigues, Carmen San Nicolas Martinez, Ângela Santos, Sérgio Sousa, Pedro T. P. Viana

Comments: Published in The Messenger (ESO)
Subjects: Solar and Stellar Astrophysics (astro-ph.SR); Earth and Planetary Astrophysics (astro-ph.EP); Instrumentation and Methods for Astrophysics (astro-ph.IM)
Cite as: arXiv:2505.08540 [astro-ph.SR] (or arXiv:2505.08540v1 [astro-ph.SR] for this version)
https://doi.org/10.48550/arXiv.2505.08540
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Journal reference: 2025, The Messenger 194, 21-25
Related DOI:
https://doi.org/10.18727/0722-6691/5381
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Submission history
From: Nuno C. Santos
[v1] Tue, 13 May 2025 13:12:01 UTC (1,722 KB)
https://arxiv.org/abs/2505.08540
Astrobiology,

Keith Cowing

Explorers Club Fellow, ex-NASA Space Station Payload manager/space biologist, Away Teams, Journalist, Lapsed climber, Synaesthete, Na’Vi-Jedi-Freman-Buddhist-mix, ASL, Devon Island and Everest Base Camp veteran, (he/him) 🖖🏻

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