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  • Technical Review
  • Published:

Data challenges and prospects of high-resolution spectroscopy of exoplanets

Nature Reviews Physics volume 7, pages 645–659 (2025)Cite this article

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Abstract

Understanding the atmospheres of exoplanets is crucial for unravelling their formation, evolution and potential habitability. High-resolution cross-correlation spectroscopy (HRCCS) has emerged as a powerful tool for probing exoplanetary atmospheres, enabling the detection of molecular species and the characterization of atmospheric dynamics. However, the reliability of these detections depends critically on the accuracy of laboratory spectroscopic data, particularly precise line positions and the careful statistical treatment of observational data. This Technical Review explores the interplay between laboratory data and high-resolution exoplanet spectroscopy, emphasizing the growing shift from isolated molecular detections to comprehensive whole-atmosphere characterization. We discuss the specific challenges of producing high-quality laboratory data and outline the needs of the exoplanetary community in this context. Key topics include the reliability of HRCCS detections, typical jargon of HRCCS and the ethical considerations in data attribution. By bridging the perspectives of laboratory spectroscopy, quantum chemistry and observational astronomy, we provide recommendations for advancing the field towards a more robust and self-consistent framework for exoplanetary atmospheric studies.

Key points

  • High-resolution cross-correlation spectroscopy (HRCCS) is a powerful tool. It has become a leading method for characterizing exoplanet atmospheres from ground-based observatories.

  • Laboratory data are crucial. The accuracy and completeness of molecular line lists and laboratory data directly affect the reliability of HRCCS detections.

  • Interdisciplinary collaboration is needed. Stronger communication between astrophysicists, spectroscopists and database providers is essential to ensure that laboratory data meet the needs of exoplanet spectroscopy.

  • False positives and non-detections remain a challenge. HRCCS detections can be affected by incomplete or inaccurate spectroscopic data, necessitating robust statistical methods and improved molecular databases.

  • Future telescopes will push the field forward. Next-generation ground-based facilities such as the Extremely Large Telescope, the Giant Magellan Telescope and the Thirty Meter Telescope will expand HRCCS applications, requiring even more precise spectroscopic data to maximize their scientific impact.

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Fig. 1: Spectra of seven molecules detected using high-resolution cross-correlation spectroscopy, based on line lists from ExoMol and HITRAN.
Fig. 2: Examples of high-resolution cross-correlation spectroscopy detections.
Fig. 3: Synthetic spectra of molecules.
Fig. 4: Spectra of sulfur-bearing molecules with high-quality ExoMol line lists for high-resolution cross-correlation spectroscopy studies at T = 1,700 K.

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References

  1. Sing, D. K. et al. A continuum from clear to cloudy hot-Jupiter exoplanets without primordial water depletion. Nature 529, 59–62 (2016).

    ADS  Google Scholar 

  2. Mansfield, M. et al. A unique hot Jupiter spectral sequence with evidence for compositional diversity. Nat. Astron. 5, 1224–1232 (2021).

    ADS  Google Scholar 

  3. Kempton, E. M.-R. et al. A framework for prioritizing the TESS planetary candidates most amenable to atmospheric characterization. Publ. Astron. Soc. Pac. 130, 114401 (2018).

    ADS  Google Scholar 

  4. Lagrange, A.-M. Direct imaging of exoplanets. Philos. Trans. A Math. Phys. Eng. Sci. 372, 20130090 (2014).

    ADS  Google Scholar 

  5. Currie, T. et al. in Protostars and Planets VII. Astronomical Society of the Pacific Conference Series Vol. 534 (eds Inutsuka, S. et al.) (Astronomical Society of the Pacific, 2023).

  6. Barstow, J. K., Aigrain, S., Irwin, P. G. J., Kendrew, S. & Fletcher, L. N. Transit spectroscopy with James Webb Space Telescope: systematics, starspots and stitching. Mon. Not. R. Astron. Soc. 448, 2546–2561 (2015).

    ADS  Google Scholar 

  7. Madhusudhan, N. Exoplanetary atmospheres: key insights, challenges, and prospects. Annu. Rev. Astron. Astrophys. 57, 617–663 (2019).

    ADS  Google Scholar 

  8. Kempton, E. M.-R. & Knutson, H. A. Transiting exoplanet atmospheres in the era of JWST. Rev. Mineral. Geochem. 90, 411–464 (2024).

    Google Scholar 

  9. Mayor, M. & Queloz, D. A Jupiter-mass companion to a solar-type star. Nature 378, 355–359 (1995).

    ADS  Google Scholar 

  10. Queloz, D. Echelle spectroscopy by a CCD at low signal-to-noise ratio. In Proc. 167th Symposium of the International Astronomical Union: New Developments in Array Technology and Applications (eds Philip, A. G. D. et al.) 221–229 (Kluwer, 1995).

  11. Snellen, I. A. G., de Kok, R. J., de Mooij, E. J. W. & Albrecht, S. The orbital motion, absolute mass and high-altitude winds of exoplanet HD209458b. Nature 465, 1049–1051 (2010).

    ADS  Google Scholar 

  12. Brogi, M. et al. The signature of orbital motion from the dayside of the planet τ Boötis b. Nature 486, 502–504 (2012).

    ADS  Google Scholar 

  13. Snellen, I. A. G. et al. Fast spin of the young extrasolar planet β Pictoris b. Nature 509, 63–65 (2014).

    ADS  Google Scholar 

  14. Giacobbe, P. et al. Five carbon- and nitrogen-bearing species in a hot giant planet’s atmosphere. Nature 592, 205–208 (2021).

    ADS  Google Scholar 

  15. Brogi, M. & Line, M. R. Retrieving temperatures and abundances of exoplanet atmospheres with high-resolution cross-correlation spectroscopy. Astrophys. J. 157, 114 (2019).

    Google Scholar 

  16. Öberg, K. I., Murray-Clay, R. & Bergin, E. A. The effects of snowlines on C/O in planetary atmospheres. Astrophys. J. Lett. 743, 16 (2011).

    ADS  Google Scholar 

  17. Mordasini, C., van Boekel, R., Mollière, P., Henning, T. & Benneke, B. The imprint of exoplanet formation history on observable present-day spectra of hot Jupiters. Astrophys. J. 832, 41 (2016).

    ADS  Google Scholar 

  18. Gibson, N. P. et al. Detection of Fe I in the atmosphere of the ultra-hot Jupiter WASP-121b, and a new likelihood-based approach for Doppler-resolved spectroscopy. Mon. Not. R. Astron. Soc. 493, 2215–2228 (2020).

    ADS  Google Scholar 

  19. Pino, L. et al. Neutral iron emission lines from the dayside of KELT-9b: the GAPS program with HARPS-N at TNG XX. Astrophys. J. Lett. 894, 27 (2020).

    ADS  Google Scholar 

  20. Brogi, M. et al. The Roasting Marshmallows program with IGRINS on Gemini South I: composition and climate of the ultrahot Jupiter WASP-18 b. Astron. J. 165, 91 (2023).

    ADS  Google Scholar 

  21. Louden, T. & Wheatley, P. J. Spatially resolved eastward winds and rotation of HD 189733b. Astrophys. J. Lett. 814, 24 (2015).

    ADS  Google Scholar 

  22. Brogi, M. et al. Rotation and winds of exoplanet HD 189733 b measured with high-dispersion transmission spectroscopy. Astrophys. J. 817, 106 (2016).

    ADS  Google Scholar 

  23. Wakeford, H. R. et al. HAT-P-26b: a Neptune-mass exoplanet with a well-constrained heavy element abundance. Science 356, 628–631 (2017).

    ADS  Google Scholar 

  24. Tsiaras, A., Waldmann, I. P., Tinetti, G., Tennyson, J. & Yurchenko, S. N. Water vapour in the atmosphere of the habitable-zone eight-Earth-mass planet K2 18b. Nat. Astron. 3, 1086–1091 (2019).

    ADS  Google Scholar 

  25. Taylor, J. et al. Awesome SOSS: atmospheric characterization of WASP-96b using the JWST early release observations. Mon. Not. R. Astron. Soc. 524, 817–834 (2023).

    ADS  Google Scholar 

  26. Ahrer, E.-M. et al. Identification of carbon dioxide in an exoplanet atmosphere. Nature 614, 649–652 (2023).

    ADS  Google Scholar 

  27. Dyrek, A. et al. SO2, silicate clouds, but no CH4 detected in a warm Neptune. Nature 625, 51–54 (2024).

    ADS  Google Scholar 

  28. Yurchenko, S. N., Tennyson, J., Bailey, J., Hollis, M. D. J. & Tinetti, G. Spectrum of hot methane in astronomical objects using a comprehensive computed line list. Proc. Natl Acad. Sci. USA 111, 9379–9383 (2014).

    ADS  Google Scholar 

  29. Gaudi, B. S. et al. A giant planet undergoing extreme-ultraviolet irradiation by its hot massive-star host. Nature 546, 514–518 (2017).

    ADS  Google Scholar 

  30. Sanchis-Ojeda, R. et al. Transits and occultations of an Earth-sized planet in an 8.5 hr orbit. Astrophys. J. 774, 54 (2013).

    ADS  Google Scholar 

  31. Tennyson, J. Accurate variational calculations for line lists to model the vibration rotation spectra of hot astrophysical atmospheres. WIREs Comput. Mol. Sci. 2, 698–715 (2012).

    Google Scholar 

  32. Tennyson, J. & Yurchenko, S. N. The ExoMol project: software for computing molecular line lists. Int. J. Quantum Chem. 117, 92–103 (2017).

    Google Scholar 

  33. Hoeijmakers, H. J. et al. A search for TiO in the optical high-resolution transmission spectrum of HD 209458b: hindrance due to inaccuracies in the line database. Astron. Astrophys. 575, 20 (2015).

    Google Scholar 

  34. Regt, S., Kesseli, A. Y., Snellen, I. A. G., Merritt, S. R. & Chubb, K. L. A quantitative assessment of the VO line list: inaccuracies hamper high-resolution VO detections in exoplanet atmospheres. Astron. Astrophys. 661, 109 (2022).

    Google Scholar 

  35. Tennyson, J. et al. The 2024 release of the ExoMol database: molecular line lists for exoplanet and other hot atmospheres. J. Quant. Spectrosc. Radiat. Transf. 326, 109083 (2024).

    Google Scholar 

  36. Furtenbacher, T., Császár, A. G. & Tennyson, J. MARVEL: measured active rotational–vibrational energy levels. J. Mol. Spectrosc. 245, 115–125 (2007).

    ADS  Google Scholar 

  37. Al-Derzi, A. R. et al. An improved rovibrational linelist of formaldehyde, H212C16O. J. Quant. Spectrosc. Radiat. Transf. 266, 107563 (2021).

    Google Scholar 

  38. Bowesman, C. A., Qu, Q., McKemmish, L. K., Yurchenko, S. N. & Tennyson, J. ExoMol line lists — LV: hyperfine-resolved molecular line list for vanadium monoxide (51V16O). Mon. Not. R. Astron. Soc. 529, 1321–1332 (2024).

    ADS  Google Scholar 

  39. Tennyson, J. et al. The 2020 release of the ExoMol database: molecular line lists for exoplanet and other hot atmospheres. J. Quant. Spectrosc. Radiat. Transf. 255, 107228 (2020).

    Google Scholar 

  40. Zhang, J., Hill, C., Tennyson, J. & Yurchenko, S. N. ExoMolHR: a relational database of empirical high-resolution molecular spectra. Astrophys. J. Suppl. Ser. 276, 67 (2025).

    ADS  Google Scholar 

  41. Parker, L. T. et al. Into the red: an M-band study of the chemistry and rotation of β Pictoris b at high spectral resolution. Mon. Not. R. Astron. Soc. 531, 2356–2378 (2024).

    ADS  Google Scholar 

  42. Madhusudhan, N. et al. Carbon-bearing molecules in a possible Hycean atmosphere. Astrophys. J. Lett. 956, 13 (2023).

    ADS  MathSciNet  Google Scholar 

  43. Wogan, N. F. et al. JWST observations of K2-18b can be explained by a gas-rich mini-Neptune with no habitable surface. Astrophys. J. Lett. 963, 7 (2024).

    ADS  Google Scholar 

  44. Holmberg, M. & Madhusudhan, N. Possible Hycean conditions in the sub-Neptune TOI-270 d. Astron. Astrophys. 683, 2 (2024).

    ADS  Google Scholar 

  45. Carleo, I. et al. The GAPS programme at TNG XXXIX. Multiple molecular species in the atmosphere of the warm giant planet WASP-80 b unveiled at high resolution with GIANO-B*. Astron. J. 164, 101 (2022).

    ADS  Google Scholar 

  46. Biassoni, F., Borsa, F., Haardt, F. & Rainer, M. High-resolution transmission spectroscopy of the hot-Saturn HD 149026b. Astron. Astrophys. 691, 283 (2024).

    ADS  Google Scholar 

  47. Brogi, M., Line, M., Bean, J., Désert, J.-M. & Schwarz, H. A framework to combine low- and high-resolution spectroscopy for the atmospheres of transiting exoplanets. Astrophys. J. Lett. 839, 2 (2017).

    ADS  Google Scholar 

  48. Miles, B. E. et al. The JWST Early Release Science Program for Direct Observations of Exoplanetary Systems II: a 1 to 20 μm spectrum of the planetary-mass companion VHS 1256-1257 b. Astrophys. J. Lett. 946, 6 (2023).

    ADS  Google Scholar 

  49. Madhusudhan, N. C/O ratio as a dimension for characterizing exoplanetary atmospheres. Astrophys. J. 758, 36 (2012).

    ADS  Google Scholar 

  50. Zhang, Y. et al. The 13CO-rich atmosphere of a young accreting super-Jupiter. Nature 595, 370–372 (2021).

    ADS  Google Scholar 

  51. Li, G. et al. Rovibrational line lists for nine isotopologues of the CO molecule in the X1Σ+ ground electronic state. Astrophys. J. Suppl. Ser. 216, 15 (2015).

    ADS  Google Scholar 

  52. Birkby, J. L. et al. Detection of water absorption in the day side atmosphere of HD 189733 b using ground-based high-resolution spectroscopy at 3.2 μm. Mon. Not. R. Astron. Soc. 436, 35–39 (2013).

    Google Scholar 

  53. Wakeford, H. R. et al. HST hot Jupiter transmission spectral survey: detection of water in HAT-P-1b from WFC3 near-IR spatial scan observations. Mon. Not. R. Astron. Soc. 435, 3481–3493 (2013).

    ADS  Google Scholar 

  54. Rothman, L. S. et al. The HITRAN 2008 molecular spectroscopic database. J. Quant. Spectrosc. Radiat. Transf. 110, 533–572 (2009).

    ADS  Google Scholar 

  55. Rothman, L. S. et al. HITEMP, the high-temperature molecular spectroscopic database. J. Quant. Spectrosc. Radiat. Transf. 111, 2139–2150 (2010).

    ADS  Google Scholar 

  56. Polyansky, O. L. et al. ExoMol molecular line lists XXX: a complete high-accuracy line list for water. Mon. Not. R. Astron. Soc. 480, 2597–2608 (2018).

    ADS  Google Scholar 

  57. Barber, R. J., Tennyson, J., Harris, G. J. & Tolchenov, R. N. A high accuracy computed water line list. Mon. Not. R. Astron. Soc. 368, 1087–1094 (2006).

    ADS  Google Scholar 

  58. Melin, S. T., Sanders, S. T. & Nasir, E. F. Comparison of ExoMol simulated spectra for H2O to high-temperature low-pressure gas cell measurements at 1723K in the 7321–7598 cm−1 range. J. Quant. Spectrosc. Radiat. Transf. 253, 107079 (2020).

    Google Scholar 

  59. Gandhi, S. et al. Molecular cross-sections for high-resolution spectroscopy of super-Earths, warm Neptunes, and hot Jupiters. Mon. Not. R. Astron. Soc. 495, 224–237 (2020).

    ADS  Google Scholar 

  60. Partridge, H. & Schwenke, D. W. The determination of an accurate isotope dependent potential energy surface for water from extensive ab initio calculations and experimental data. J. Chem. Phys. 106, 4618–4639 (1997).

    ADS  Google Scholar 

  61. Flowers, E., Brogi, M., Rauscher, E., Kempton, E. M.-R. & Chiavassa, A. The high-resolution transmission spectrum of HD 189733b interpreted with atmospheric Doppler shifts from three-dimensional general circulation models. Astron. J. 157, 209 (2019).

    ADS  Google Scholar 

  62. Fortney, J. J., Lodders, K., Marley, M. S. & Freedman, R. S. A unified theory for the atmospheres of the hot and very hot Jupiters: two classes of irradiated atmospheres. Astrophys. J. 678, 1419–1435 (2008).

    ADS  Google Scholar 

  63. Parmentier, Vivien et al. From thermal dissociation to condensation in the atmospheres of ultra hot Jupiters: WASP-121b in context. Astron. Astrophys. 617, 110 (2018).

    Google Scholar 

  64. Burrows, A. & Sharp, C. M. Chemical equilibrium abundances in brown dwarf and extrasolar giant planet atmospheres. Astrophys. J. 512, 843–863 (1999).

    ADS  Google Scholar 

  65. Sedaghati, E. et al. Detection of titanium oxide in the atmosphere of a hot Jupiter. Nature 549, 238–241 (2017).

    ADS  Google Scholar 

  66. Nugroho, S. K. et al. High-resolution spectroscopic detection of TiO and a stratosphere in the day-side of WASP-33b. Astrophys. J. 154, 221 (2017).

    Google Scholar 

  67. Schwenke, D. W. Opacity of TiO from a coupled electronic state calculation parametrized by ab initio and experimental data. Faraday Discuss. 109, 321–334 (1998).

    ADS  Google Scholar 

  68. McKemmish, L. K. et al. ExoMol molecular line lists — XXXIII. The spectrum of titanium oxide. Mon. Not. R. Astron. Soc. 488, 2836–2854 (2019).

    ADS  Google Scholar 

  69. Serindag, D. B. et al. Is TiO emission present in the ultra-hot Jupiter WASP-33b? A reassessment using the improved ExoMol TOTO line list. Astron. Astrophys. 645, 90 (2021).

    Google Scholar 

  70. Prinoth, B. et al. Titanium oxide and chemical inhomogeneity in the atmosphere of the exoplanet WASP-189 b. Nat. Astron. 6, 449–457 (2022).

    ADS  Google Scholar 

  71. Witsch, D. et al. The rotationally resolved infrared spectrum of TiO and its isotopologues. J. Mol. Spectrosc. 377, 111439 (2021).

    Google Scholar 

  72. Cameron, W. D. & Bernath, P. Visible opacity of M dwarfs and hot Jupiters: the TiO B3Π–X3Δ band system. Astrophys. J. 926, 39 (2022).

    ADS  Google Scholar 

  73. Bernath, P. & Cameron, D. Line lists for TiO minor isotopologues for the A3Φ–X3Δ electronic transition. J. Quant. Spectrosc. Radiat. Transf. 310, 108745 (2023).

    Google Scholar 

  74. McKemmish, L. K. et al. A hybrid approach to generating diatomic line lists for high resolution studies of exoplanets and other hot astronomical objects: updates to ExoMol MgO, VO and TiO line lists. RAS Tech. Instrum. 3, 565–583 (2024).

    ADS  Google Scholar 

  75. Pelletier, S. et al. Vanadium oxide and a sharp onset of cold-trapping on a giant exoplanet. Nature 619, 491–494 (2023).

    ADS  Google Scholar 

  76. McKemmish, L. K., Yurchenko, S. N. & Tennyson, J. ExoMol line lists — XVIII. The high-temperature spectrum of VO. Mon. Not. R. Astron. Soc. 463, 771–793 (2016).

    ADS  Google Scholar 

  77. Bowesman, C. A., Akbari, H., Hopkins, S., Yurchenko, S. N. & Tennyson, J. Fine and hyperfine resolved empirical energy levels for VO. J. Quant. Spectrosc. Radiat. Transf. 289, 108295 (2022).

    Google Scholar 

  78. Qu, Q., Yurchenko, S. N. & Tennyson, J. A method for the variational calculation of hyperfine-resolved rovibronic spectra of diatomic molecules. J. Chem. Theory Comput. 18, 1808–1820 (2022).

    Google Scholar 

  79. Qu, Q., Yurchenko, S. N. & Tennyson, J. A variational model for the hyperfine resolved spectrum of VO in its ground electronic state. J. Chem. Phys. 157, 124305 (2022).

    ADS  Google Scholar 

  80. Qu, Q., Yurchenko, S. N. & Tennyson, J. An empirical spectroscopic model for eleven electronic states of VO. J. Mol. Spectrosc. 391, 111733 (2023).

    Google Scholar 

  81. Bowesman, C. A., Yurchenko, S. N. & Tennyson, J. A hyperfine-resolved spectroscopic model for vanadium monoxide (51V16O). Mol. Phys. 122, 2255299 (2024).

    ADS  Google Scholar 

  82. Simonnin, A. et al. Time resolved absorption of six chemical species with MAROON-X points to strong drag in the ultra hot Jupiter TOI-1518 b. Preprint at https://arxiv.org/abs/2412.01472 (2024).

  83. Maguire, C. et al. High resolution atmospheric retrievals of WASP-76b transmission spectroscopy with ESPRESSO: monitoring limb asymmetries across multiple transits. Astron. Astrophys. 687, 49 (2024).

    Google Scholar 

  84. Nugroho, S. K. et al. First detection of hydroxyl radical emission from an exoplanet atmosphere: high-dispersion characterization of WASP-33b using Subaru/IRD. Astrophys. J. Lett. 910, 9 (2021).

    ADS  Google Scholar 

  85. Brooke, J. S. A. et al. Line strengths of rovibrational and rotational transitions in the X2Π ground state of OH. J. Quant. Spectrosc. Radiat. Transf. 138, 142–157 (2016).

    ADS  Google Scholar 

  86. Wright, S. O. M. et al. A spectroscopic thermometer: individual vibrational band spectroscopy with the example of OH in the atmosphere of WASP-33b. Astron. J. 166, 41 (2023).

    ADS  Google Scholar 

  87. Mitev, G. B., Yurchenko, S. N. & Tennyson, J. Predissociation dynamics of the hydroxyl radical (OH) based on a five-state spectroscopic model. J. Chem. Phys. 160, 144110 (2024).

    ADS  Google Scholar 

  88. Cont, D. et al. Exploring the ultra-hot Jupiter WASP-178b — constraints on atmospheric chemistry and dynamics from a joint retrieval of VLT/CRIRES+ and space photometric data. Astron. Astrophys. 688, 206 (2024).

    Google Scholar 

  89. Mitev, G. B. et al. ExoMol photodissociation cross-sections – II. Continuum absorption and pre-dissociation spectra for the hydroxyl radical. Mon. Not. R. Astron. Soc. 539, 3732–3740 (2025).

    ADS  Google Scholar 

  90. Bell, T. J. et al. Methane throughout the atmosphere of the warm exoplanet WASP-80b. Nature 623, 709–712 (2023).

    ADS  Google Scholar 

  91. Benneke, B. et al. JWST reveals CH4, CO2, and H2O in a metal-rich miscible atmosphere on a two-Earth-radius exoplanet. Preprint at https://doi.org/10.48550/arXiv.2403.03325 (2024).

  92. Wiedemann, G., Deming, D. & Bjoraker, G. A sensitive search for methane in the infrared spectrum of τ Bootis. Astrophys. J. 546, 1068–1074 (2001).

    ADS  Google Scholar 

  93. Gordon, I. E. et al. The HITRAN 2016 molecular spectroscopic database. J. Quant. Spectrosc. Radiat. Transf. 203, 3–69 (2017).

    ADS  Google Scholar 

  94. Hargreaves, R. J. et al. An accurate, extensive, and practical line list of methane for the HITEMP database. Astrophys. J. Suppl. Ser. 247, 55 (2020).

    ADS  Google Scholar 

  95. Guilluy, G. et al. The GAPS Programme at TNG. XXXVIII. Five molecules in the atmosphere of the warm giant planet WASP-69b detected at high spectral resolution. Astron. Astrophys. 665, 104 (2022).

    Google Scholar 

  96. Rey, M., Nikitin, A. V. & Tyuterev, V. G. Theoretical hot methane line lists up to T = 2000 K for astrophysical applications. Astrophys. J. 789, 2 (2014).

    ADS  Google Scholar 

  97. Rey, M., Nikitin, A. V. & Tyuterev, V. G. Accurate theoretical methane line lists in the infrared up to 3000 K and quasi-continuum absorption/emission modeling for astrophysical applications. Astrophys. J. 847, 105 (2017).

    ADS  Google Scholar 

  98. Yurchenko, S. N. & Tennyson, J. ExoMol line lists IV: the rotation–vibration spectrum of methane up to 1500 K. Mon. Not. R. Astron. Soc. 440, 1649–1661 (2014).

    ADS  Google Scholar 

  99. Yurchenko, S. N., Owens, A., Kefala, K. & Tennyson, J. ExoMol line lists — LVII. High accuracy ro-vibrational line list for methane (CH4). Mon. Not. R. Astron. Soc. 528, 3719–3729 (2024).

    ADS  Google Scholar 

  100. Kefala, K., Boudon, V., Yurchenko, S. N. & Tennyson, J. Empirical rovibrational energy levels for methane. J. Quant. Spectrosc. Radiat. Transf. 316, 108897 (2024).

    Google Scholar 

  101. Madhusudhan, N. & Seager, S. A temperature and abundance retrieval method for exoplanet atmospheres. Astrophys. J. 707, 24–39 (2009).

    ADS  Google Scholar 

  102. Pelletier, S. et al. Where is the water? Jupiter-like C/H ratio but strong H2O depletion found on τ Boötis b using SPIRou. Astron. J. 162, 73 (2021).

    ADS  Google Scholar 

  103. Line, M. R. et al. A solar C/O and sub-solar metallicity in a hot Jupiter atmosphere. Nature 598, 580 (2021).

    ADS  Google Scholar 

  104. Gandhi, S. et al. Retrieval survey of metals in six ultrahot Jupiters: trends in chemistry, rain-out, ionization, and atmospheric dynamics. Astron. J. 165, 242 (2023).

    ADS  Google Scholar 

  105. Kirk, J. et al. BOWIE-ALIGN: JWST reveals hints of planetesimal accretion and complex sulphur chemistry in the atmosphere of the misaligned hot Jupiter WASP-15b. Mon. Not. R. Astron. Soc. 537, 3027–3052 (2025).

    ADS  Google Scholar 

  106. Owens, A., Yurchenko, S. N. & Tennyson, J. ExoMol line lists — LVIII. High-temperature molecular line list of carbonyl sulphide (OCS). Mon. Not. R. Astron. Soc. 530, 4004–4015 (2024).

    ADS  Google Scholar 

  107. Underwood, D. S. et al. ExoMol line lists XIV: a line list for hot SO2. Mon. Not. R. Astron. Soc. 459, 3890–3899 (2016).

    ADS  Google Scholar 

  108. Azzam, A. A. A., Yurchenko, S. N., Tennyson, J. & Naumenko, O. V. ExoMol line lists — XVI. The rotation–vibration spectrum of hot H2S. Mon. Not. R. Astron. Soc. 460, 4063–4074 (2016).

    ADS  Google Scholar 

  109. Gorman, M. N., Yurchenko, S. N. & Tennyson, J. ExoMol molecular line lists — XXXVI. X2Π–X2Π and A2Σ+–X2Π transitions of SH. Mon. Not. R. Astron. Soc. 490, 1652–1665 (2019).

    ADS  Google Scholar 

  110. Brady, R. P., Yurchenko, S. N., Tennyson, J. & Kim, G.-S. ExoMol line lists — LVI. The SO line list, MARVEL analysis of experimental transition data and refinement of the spectroscopic model. Mon. Not. R. Astron. Soc. 527, 6675–6690 (2024).

    ADS  Google Scholar 

  111. Zilinskas, M. et al. Observability of evaporating lava worlds. Astron. Astrophys. 661, 126 (2022).

    Google Scholar 

  112. Sakellaris, C. N., Miliordos, E. & Mavridis, A. First principles study of the ground and excited states of FeO, FeO+, and FeO−. J. Chem. Phys. 134, 234308 (2011).

    ADS  Google Scholar 

  113. Cheung, A. S.-C., Lyyra, A. M., Merer, A. J. & Taylor, A. W. Laser spectroscopy of FeO: rotational analysis of some subbands of the orange system. J. Mol. Spectrosc. 102, 224–257 (1983).

    ADS  Google Scholar 

  114. Allen, M. D., Ziurys, L. M. & Brown, J. M. The millimeter-wave spectrum of FeO in its X5Δi state (v = 0): a study of all five spin components. Chem. Phys. Lett. 257, 130–136 (1996).

    ADS  Google Scholar 

  115. Owens, A., Conway, E. K., Tennyson, J. & Yurchenko, S. N. ExoMol linelists — XXXVIII. High-temperature molecular line list of silicon dioxide (SiO2). Mon. Not. R. Astron. Soc. 495, 1927–1933 (2020).

    ADS  Google Scholar 

  116. Cheverall, C. J., Madhusudhan, N. & Holmberg, M. Robustness measures for molecular detections using high-resolution transmission spectroscopy of exoplanets. Mon. Not. R. Astron. Soc. 522, 661–677 (2023).

    ADS  Google Scholar 

  117. Grimm, S. L. et al. HELIOS-K 2.0 and an open-source opacity database for exoplanetary atmospheres. Astrophys. J. Suppl. Ser. 253, 30 (2021).

    ADS  Google Scholar 

  118. Chubb, K. L. et al. The ExoMolOP database: cross-sections and K-tables for molecules of interest in high-temperature exoplanet atmospheres. Astron. Astrophys. 646, 21 (2021).

    Google Scholar 

  119. Wallace, L., Livingston, W., Hinkle, K. & Bernath, P. Infrared spectral atlases of the Sun from NOAO. Astrophys. J. Suppl. Ser. 106, 165–169 (1996).

    ADS  Google Scholar 

  120. Berné, O. et al. Formation of the methyl cation by photochemistry in a protoplanetary disk. Nature 621, 56–59 (2023).

    ADS  Google Scholar 

  121. Ariyarathna, I. R., Leiding, J. A., Neukirch, A. J. & Zammit, M. C. Ground and excited electronic structure analysis of FeH with correlated wave function theory and density functional approximations. J. Phys. Chem. A 128, 9412–9425 (2024).

    Google Scholar 

  122. Schwarz, H. et al. The slow spin of the young substellar companion GQ Lupi b and its orbital configuration. Astron. Astrophys. 593, 74 (2016).

    Google Scholar 

  123. Sánchez-López, A. et al. Water vapor detection in the transmission spectra of HD 209458 b with the CARMENES NIR channel. Astron. Astrophys. 630, 53 (2019).

    Google Scholar 

  124. Guilluy, G. et al. Exoplanet atmospheres with GIANO — II. Detection of molecular absorption in the dayside spectrum of HD 102195b. Astron. Astrophys. 625, 107 (2019).

    Google Scholar 

  125. Hawker, G. A., Madhusudhan, N., Cabot, S. H. C. & Gandhi, S. Evidence for multiple molecular species in the hot Jupiter HD 209458b. Astrophys. J. Lett. 863, 11 (2018).

    ADS  Google Scholar 

  126. Barber, R. J. et al. ExoMol line lists — III. An improved hot rotation–vibration line list for HCN and HNC. Mon. Not. R. Astron. Soc. 437, 1828–1835 (2014).

    ADS  Google Scholar 

  127. Cabot, S. H. C., Madhusudhan, N., Hawker, G. A. & Gandhi, S. On the robustness of analysis techniques for molecular detections using high-resolution exoplanet spectroscopy. Mon. Not. R. Astron. Soc. 482, 4422–4436 (2019).

    ADS  Google Scholar 

  128. Coles, P. A., Yurchenko, S. N. & Tennyson, J. ExoMol molecular line lists XXXV. A rotation–vibration line list for hot ammonia. Mon. Not. R. Astron. Soc. 490, 4638–4647 (2019).

    ADS  Google Scholar 

  129. Chubb, K. L., Tennyson, J. & Yurchenko, S. N. ExoMol molecular linelists — XXXVII. Spectra of acetylene. Mon. Not. R. Astron. Soc. 493, 1531–1545 (2020).

    ADS  Google Scholar 

  130. Flagg, L. et al. ExoGemS detection of a metal hydride in an exoplanet atmosphere at high spectral resolution. Astrophys. J. Lett. 953, 19 (2023).

    ADS  Google Scholar 

  131. Burrows, A., Ram, R. S., Bernath, P., Sharp, C. M. & Milsom, J. A. New CrH opacities for the study of L and brown dwarf atmospheres. Astrophys. J. 577, 986–992 (2002).

    ADS  Google Scholar 

  132. Bernath, P. F. MoLLIST: molecular line lists, intensities and spectra. J. Quant. Spectrosc. Radiat. Transf. 240, 106687 (2020).

    Google Scholar 

  133. Landman, R. et al. Detection of OH in the ultra-hot Jupiter WASP-76b. Astron. Astrophys. 656, 119 (2021).

    Google Scholar 

  134. Smith, P. C. B. et al. A combined ground-based and JWST atmospheric retrieval analysis: both IGRINS and NIRSpec agree that the atmosphere of WASP-77A b is metal-poor. Astron. J. 167, 110 (2024).

    ADS  Google Scholar 

  135. Gordon, I. E. et al. The HITRAN2020 molecular spectroscopic database. J. Quant. Spectrosc. Radiat. Transf. 277, 107949 (2022).

    Google Scholar 

  136. Hargreaves, R. J. et al. Spectroscopic line parameters of NO, NO2, and N2O for the HITEMP database. J. Quant. Spectrosc. Radiat. Transf. 232, 35–53 (2019).

    ADS  Google Scholar 

  137. Jacquinet-Husson, N. et al. The 2015 edition of the GEISA spectroscopic database. J. Mol. Spectrosc. 327, 31–72 (2016).

    ADS  Google Scholar 

  138. Kurucz, R. L. Including all the lines. Can. J. Phys. 89, 417–428 (2011).

    ADS  Google Scholar 

  139. Ryabchikova, T. et al. A major upgrade of the VALD database. Phys. Scr. 90, 054005 (2015).

    ADS  Google Scholar 

  140. Rey, M., Nikitin, A. V., Babikov, Y. L. & Tyuterev, V. G. TheoReTS — an information system for theoretical spectra based on variational predictions from molecular potential energy and dipole moment surfaces. J. Mol. Spectrosc. 327, 138–158 (2016).

    ADS  Google Scholar 

  141. Huang, X., Freedman, R. S., Tashkun, S., Schwenke, D. W. & Lee, T. J. AI-3000K infrared line list for hot CO2. J. Mol. Spectrosc. 392, 111748 (2023).

    Google Scholar 

  142. Richard, C., Boudon, V. & Rotger, M. Calculated spectroscopic databases for the VAMDC portal: new molecules and improvements. J. Quant. Spectrosc. Radiat. Transf. 251, 107096 (2020).

    Google Scholar 

  143. Endres, C. P., Schlemmer, S., Schilke, P., Stutzki, J. & Müller, H. S. P. The Cologne Database for Molecular Spectroscopy, CDMS, in the Virtual Atomic and Molecular Data Centre, VAMDC. J. Mol. Spectrosc. 327, 95–104 (2016).

    ADS  Google Scholar 

  144. Pickett, H. M. et al. Submillimeter, millimeter, and microwave spectral line catalog. J. Quant. Spectrosc. Radiat. Transf. 60, 883–890 (1998).

    ADS  Google Scholar 

  145. Venot, O. et al. A chemical model for the atmosphere of hot Jupiters. Astron. Astrophys. 546, 43 (2012).

    Google Scholar 

  146. Moses, J. I. Chemical kinetics on extrasolar planets. Philos. Trans. A Math. Phys. Eng. Sci. 372, 20130073 (2014).

    ADS  Google Scholar 

  147. Shabram, M., Fortney, J. J., Greene, T. P. & Freedman, R. S. Transmission spectra of transiting planet atmospheres: model validation and simulations of the hot Neptune GJ 436b for the James Webb Space Telescope. Astrophys. J. 727, 65 (2011).

    ADS  Google Scholar 

  148. Yurchenko, S. N. et al. ExoMol linelists — XXIV: a new hot line list for silicon monohydride, SiH. Mon. Not. R. Astron. Soc. 473, 5324–5333 (2018).

    ADS  Google Scholar 

  149. Irwin, P. G. J. et al. Analysis of gaseous ammonia (NH3) absorption in the visible spectrum of Jupiter — update. Icarus 321, 572–582 (2019).

    ADS  Google Scholar 

  150. Barton, E. J., Yurchenko, S. N., Tennyson, J., Béguier, S. & Campargue, A. A near infrared line list for NH3: analysis of a Kitt Peak spectrum after 35 years. J. Mol. Spectrosc. 325, 7–12 (2016).

    ADS  Google Scholar 

  151. Basilicata, M. et al. The GAPS programme at TNG. Astron. Astrophys. 686, A127 (2024).

    Google Scholar 

  152. Xue, Q. et al. JWST transmission spectroscopy of HD 209458b: a supersolar metallicity, a very low C/O, and no evidence of CH4, HCN, or C2H2. Astrophys. J. Lett. 963, 5 (2024).

    ADS  Google Scholar 

  153. Yurchenko, S. N., Mellor, T. M., Freedman, R. S. & Tennyson, J. ExoMol line lists XXXIX. Ro-vibrational molecular line list for CO2. Mon. Not. R. Astron. Soc. 496, 5282–5291 (2020).

    ADS  Google Scholar 

  154. Schaefer, L. & Fegley, B. Chemistry of silicate atmospheres of evaporating super-Earths. Astrophys. J. 703, 113–117 (2009).

    ADS  Google Scholar 

  155. Kite, E. S., Fegley, B., Schaefer, L. & Gaidos, E. Atmosphere–interior exchange on hot, rocky exoplanets. Astrophys. J. 828, 80 (2016).

    ADS  Google Scholar 

  156. Kesseli, A. Y., Snellen, I. A. G., Alonso-Floriano, F. J., Mollière, P. & Serindag, D. B. A search for FeH in hot-Jupiter atmospheres with high-dispersion spectroscopy. Astron. J. 160, 228 (2020).

    ADS  Google Scholar 

  157. Pavlenko, Y. V. Theoretical modelling of optical and IR spectra of brown dwarfs and ultracool dwarfs. Astron. Nachr. 326, 934–939 (2005).

    ADS  Google Scholar 

  158. Reiners, A., Homeier, D., Hauschildt, P. H. & Allard, F. A high resolution spectral atlas of brown dwarfs. Astron. Astrophys. 473, 245–255 (2007).

    ADS  Google Scholar 

  159. Crozet, P. et al. Correlations between laboratory line lists for FeH, CrH, and NiH and M-star spectra collected with ESPaDOnS and SPIRou. Astron. Astrophys. 679, 116 (2023).

    Google Scholar 

  160. Lyulin, O., Vasilchenko, S., Mondelain, D. & Campargue, A. The CRDS spectrum of acetylene near 1.73 μm. J. Quant. Spectrosc. Radiat. Transf. 234, 147–158 (2019).

    ADS  Google Scholar 

  161. Jacquemart, D., Soulard, P. & Lyulin, O. M. Recommended acetylene 12C2H2 line list in 13.6 μm spectral region: new measurements and global modeling. J. Quant. Spectrosc. Radiat. Transf. 256, 107200 (2020).

    Google Scholar 

  162. Lyulin, O. M., Vasilchenko, S. S. & Perevalov, V. I. High sensitivity absorption spectroscopy of acetylene near 770 nm. J. Quant. Spectrosc. Radiat. Transf. 294, 108402 (2023).

    Google Scholar 

  163. Currie, T. et al. Direct imaging and spectroscopy of extrasolar planets. Preprint at https://arxiv.org/abs/2205.05696 (2023).

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Acknowledgements

The idea for this Technical Review arose from the Royal Society Discussion Meeting on Exoplanet Spectroscopy at High Resolution held near Northampton, UK, in 2023. We thank the other attendees at this meeting for conversations and the Royal Society for funding under the Theo Murphy meeting programme. The work of J.T. and S.Y. and the ExoMol project received support from the European Research Council under the European Union’s Horizon 2020 research and innovation programme through Advance Grant numbers 267219 and 883830. S.Y. also acknowledges Science and Technology Facilities Council (STFC) Project No. ST/Y001508/1 and the use of the DiRAC HPC services at Cambridge and Leicester funded by BEIS, UKRI and STFC capital funding and STFC operations grants.

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Authors and Affiliations

  1. Department of Physics and Astronomy, University College London, London, UK

    Sergei N. Yurchenko & Jonathan Tennyson

  2. Dipartimento di Fisica, Università degli Studi di Torino, Turin, Italy

    Matteo Brogi

  3. Osservatorio Astrofisico di Torino, INAF, Pino Torinese, Italy

    Matteo Brogi

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  1. Sergei N. Yurchenko
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Correspondence to Sergei N. Yurchenko.

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Glossary

Bayesian retrievals

A statistical approach used to infer atmospheric properties of exoplanets by comparing observed spectra to models, incorporating prior knowledge and uncertainties.

Cross-correlation function

(CCF). A mathematical tool used in HRCCS to measure the similarity between an observed spectrum and a model template, enhancing weak signals buried in noise.

Direct imaging

A method of detecting exoplanets by capturing their light separately from the host star, typically using adaptive optics and coronagraphy to suppress stellar glare.

High-resolution cross-correlation spectroscopy

(HRCCS). A spectroscopic technique that enhances the detection of molecular species in exoplanet atmospheres by cross correlating observed spectra with model templates at high spectral resolution.

Measured active rotational–vibrational energy levels

(MARVEL). A data-driven approach that refines spectroscopic line lists by combining experimental measurements with theoretical calculations to provide highly accurate molecular energy levels.

Resolving power

A measure of a spectrograph’s ability to distinguish between closely spaced spectral features, defined as R = λ/Δλ, where λ is the wavelength and Δλ is the smallest detectable difference.

Secondary eclipse

The moment when an exoplanet moves behind its host star, allowing astronomers to isolate and analyse the planet’s thermal emission and reflected light.

Transit

The passage of an exoplanet in front of its host star, causing a temporary dip in the star’s brightness, which allows for atmospheric characterization through transmission spectroscopy.

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Yurchenko, S.N., Tennyson, J. & Brogi, M. Data challenges and prospects of high-resolution spectroscopy of exoplanets. Nat Rev Phys 7, 645–659 (2025). https://doi.org/10.1038/s42254-025-00839-z

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