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The CHEOPS mission

Benz, W. ; Broeg, C. ; Fortier, A. ; Rando, N. ; Beck, T. ; Beck, M. LU ; Queloz, D. ; Ehrenreich, D. ; Maxted, P. F.L. and Isaak, K. G. , et al. (2021) In Experimental Astronomy 51(1). p.109-151
Abstract

The CHaracterising ExOPlanet Satellite (CHEOPS) was selected on October 19, 2012, as the first small mission (S-mission) in the ESA Science Programme and successfully launched on December 18, 2019, as a secondary passenger on a Soyuz-Fregat rocket from Kourou, French Guiana. CHEOPS is a partnership between ESA and Switzerland with important contributions by ten additional ESA Member States. CHEOPS is the first mission dedicated to search for transits of exoplanets using ultrahigh precision photometry on bright stars already known to host planets. As a follow-up mission, CHEOPS is mainly dedicated to improving, whenever possible, existing radii measurements or provide first accurate measurements for a subset of those planets for which... (More)

The CHaracterising ExOPlanet Satellite (CHEOPS) was selected on October 19, 2012, as the first small mission (S-mission) in the ESA Science Programme and successfully launched on December 18, 2019, as a secondary passenger on a Soyuz-Fregat rocket from Kourou, French Guiana. CHEOPS is a partnership between ESA and Switzerland with important contributions by ten additional ESA Member States. CHEOPS is the first mission dedicated to search for transits of exoplanets using ultrahigh precision photometry on bright stars already known to host planets. As a follow-up mission, CHEOPS is mainly dedicated to improving, whenever possible, existing radii measurements or provide first accurate measurements for a subset of those planets for which the mass has already been estimated from ground-based spectroscopic surveys. The expected photometric precision will also allow CHEOPS to go beyond measuring only transits and to follow phase curves or to search for exo-moons, for example. Finally, by unveiling transiting exoplanets with high potential for in-depth characterisation, CHEOPS will also provide prime targets for future instruments suited to the spectroscopic characterisation of exoplanetary atmospheres. To reach its science objectives, requirements on the photometric precision and stability have been derived for stars with magnitudes ranging from 6 to 12 in the V band. In particular, CHEOPS shall be able to detect Earth-size planets transiting G5 dwarf stars (stellar radius of 0.9R) in the magnitude range 6 ≤ V ≤ 9 by achieving a photometric precision of 20 ppm in 6 hours of integration time. In the case of K-type stars (stellar radius of 0.7R) of magnitude in the range 9 ≤ V ≤ 12, CHEOPS shall be able to detect transiting Neptune-size planets achieving a photometric precision of 85 ppm in 3 hours of integration time. This precision has to be maintained over continuous periods of observation for up to 48 hours. This precision and stability will be achieved by using a single, frame-transfer, back-illuminated CCD detector at the focal plane assembly of a 33.5 cm diameter, on-axis Ritchey-Chrétien telescope. The nearly 275 kg spacecraft is nadir-locked, with a pointing accuracy of about 1 arcsec rms, and will allow for at least 1 Gbit/day downlink. The sun-synchronous dusk-dawn orbit at 700 km altitude enables having the Sun permanently on the backside of the spacecraft thus minimising Earth stray light. A mission duration of 3.5 years in orbit is foreseen to enable the execution of the science programme. During this period, 20% of the observing time is available to the wider community through yearly ESA call for proposals, as well as through discretionary time approved by ESA’s Director of Science. At the time of this writing, CHEOPS commissioning has been completed and CHEOPS has been shown to fulfill all its requirements. The mission has now started the execution of its science programme.

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organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
CHEOPS, Exoplanets, High-precision transit photometry, Small mission
in
Experimental Astronomy
volume
51
issue
1
pages
109 - 151
publisher
Springer
external identifiers
  • scopus:85095602152
ISSN
0922-6435
DOI
10.1007/s10686-020-09679-4
language
English
LU publication?
yes
id
048ba0d3-5463-4307-a41f-8fb6cd68bb82
date added to LUP
2021-01-11 16:15:49
date last changed
2021-04-27 01:36:18
@article{048ba0d3-5463-4307-a41f-8fb6cd68bb82,
  abstract     = {<p>The CHaracterising ExOPlanet Satellite (CHEOPS) was selected on October 19, 2012, as the first small mission (S-mission) in the ESA Science Programme and successfully launched on December 18, 2019, as a secondary passenger on a Soyuz-Fregat rocket from Kourou, French Guiana. CHEOPS is a partnership between ESA and Switzerland with important contributions by ten additional ESA Member States. CHEOPS is the first mission dedicated to search for transits of exoplanets using ultrahigh precision photometry on bright stars already known to host planets. As a follow-up mission, CHEOPS is mainly dedicated to improving, whenever possible, existing radii measurements or provide first accurate measurements for a subset of those planets for which the mass has already been estimated from ground-based spectroscopic surveys. The expected photometric precision will also allow CHEOPS to go beyond measuring only transits and to follow phase curves or to search for exo-moons, for example. Finally, by unveiling transiting exoplanets with high potential for in-depth characterisation, CHEOPS will also provide prime targets for future instruments suited to the spectroscopic characterisation of exoplanetary atmospheres. To reach its science objectives, requirements on the photometric precision and stability have been derived for stars with magnitudes ranging from 6 to 12 in the V band. In particular, CHEOPS shall be able to detect Earth-size planets transiting G5 dwarf stars (stellar radius of 0.9R<sub>⊙</sub>) in the magnitude range 6 ≤ V ≤ 9 by achieving a photometric precision of 20 ppm in 6 hours of integration time. In the case of K-type stars (stellar radius of 0.7R<sub>⊙</sub>) of magnitude in the range 9 ≤ V ≤ 12, CHEOPS shall be able to detect transiting Neptune-size planets achieving a photometric precision of 85 ppm in 3 hours of integration time. This precision has to be maintained over continuous periods of observation for up to 48 hours. This precision and stability will be achieved by using a single, frame-transfer, back-illuminated CCD detector at the focal plane assembly of a 33.5 cm diameter, on-axis Ritchey-Chrétien telescope. The nearly 275 kg spacecraft is nadir-locked, with a pointing accuracy of about 1 arcsec rms, and will allow for at least 1 Gbit/day downlink. The sun-synchronous dusk-dawn orbit at 700 km altitude enables having the Sun permanently on the backside of the spacecraft thus minimising Earth stray light. A mission duration of 3.5 years in orbit is foreseen to enable the execution of the science programme. During this period, 20% of the observing time is available to the wider community through yearly ESA call for proposals, as well as through discretionary time approved by ESA’s Director of Science. At the time of this writing, CHEOPS commissioning has been completed and CHEOPS has been shown to fulfill all its requirements. The mission has now started the execution of its science programme.</p>},
  author       = {Benz, W. and Broeg, C. and Fortier, A. and Rando, N. and Beck, T. and Beck, M. and Queloz, D. and Ehrenreich, D. and Maxted, P. F.L. and Isaak, K. G. and Billot, N. and Alibert, Y. and Alonso, R. and António, C. and Asquier, J. and Bandy, T. and Bárczy, T. and Barrado, D. and Barros, S. C.C. and Baumjohann, W. and Bekkelien, A. and Bergomi, M. and Biondi, F. and Bonfils, X. and Borsato, L. and Brandeker, A. and Busch, M. D. and Cabrera, J. and Cessa, V. and Charnoz, S. and Chazelas, B. and Collier Cameron, A. and Corral Van Damme, C. and Cortes, D. and Davies, M. B. and Deleuil, M. and Deline, A. and Delrez, L. and Demangeon, O. and Demory, B. O. and Erikson, A. and Farinato, J. and Fossati, L. and Fridlund, M. and Futyan, D. and Gandolfi, D. and Garcia Munoz, A. and Gillon, M. and Guterman, P. and Gutierrez, A. and Hasiba, J. and Heng, K. and Hernandez, E. and Hoyer, S. and Kiss, L. L. and Kovacs, Z. and Kuntzer, T. and Laskar, J. and Lecavelier des Etangs, A. and Lendl, M. and López, A. and Lora, I. and Lovis, C. and Lüftinger, T. and Magrin, D. and Malvasio, L. and Marafatto, L. and Michaelis, H. and de Miguel, D. and Modrego, D. and Munari, M. and Nascimbeni, V. and Olofsson, G. and Ottacher, H. and Ottensamer, R. and Pagano, I. and Palacios, R. and Pallé, E. and Peter, G. and Piazza, D. and Piotto, G. and Pizarro, A. and Pollaco, D. and Ragazzoni, R. and Ratti, F. and Rauer, H. and Ribas, I. and Rieder, M. and Rohlfs, R. and Safa, F. and Salatti, M. and Santos, N. C. and Scandariato, G. and Ségransan, D. and Simon, A. E. and Smith, A. M.S. and Sordet, M. and Sousa, S. G. and Steller, M. and Szabó, G. M. and Szoke, J. and Thomas, N. and Tschentscher, M. and Udry, S. and Van Grootel, V. and Viotto, V. and Walter, I. and Walton, N. A. and Wildi, F. and Wolter, D.},
  issn         = {0922-6435},
  language     = {eng},
  number       = {1},
  pages        = {109--151},
  publisher    = {Springer},
  series       = {Experimental Astronomy},
  title        = {The CHEOPS mission},
  url          = {http://dx.doi.org/10.1007/s10686-020-09679-4},
  doi          = {10.1007/s10686-020-09679-4},
  volume       = {51},
  year         = {2021},
}