UKRI Funded

Equivalent Width of the Interstellar Na i D 1 and D 2 Absorption Lines for Stars with E ( B − V ) < 0.15 (2025)
Journal Article
Maxted, P. F. L. (2025). Equivalent Width of the Interstellar Na i D 1 and D 2 Absorption Lines for Stars with E ( B − V ) < 0.15. Research Notes of the American Astronomical Society, 9(6), 1-5. https://doi.org/10.3847/2515-5172/ade39b

New measurements of the equivalent width of the interstellar Na i D1 and D2 absorption lines for 62 bright B-type stars with E(B − V) < 0.15 are used to recalibrate the relation between these quantities in this low-reddening regime, and to quantify t... Read More about Equivalent Width of the Interstellar Na i D 1 and D 2 Absorption Lines for Stars with E ( B − V ) < 0.15.

EBLM XV – Revised dynamical masses for the circumbinary planet host Kepler-16 AB, using the SOPHIE spectrograph (2025)
Journal Article
Sebastian, D., Boisse, I., Santerne, A., Triaud, A. H. M. J., Baycroft, T. A., Davis, Y. T., Deleuil, M., Grouffal, S., Hébrard, G., Heidari, N., Martin, D. V., Maxted, P. F. L., Nelson, R. P., Lalitha, S., Scott, M. G., Scutt, O. J., & Standing, M. (in press). EBLM XV – Revised dynamical masses for the circumbinary planet host Kepler-16 AB, using the SOPHIE spectrograph. Monthly Notices of the Royal Astronomical Society, https://doi.org/10.1093/mnras/staf863

Eclipsing binaries are perfect laboratories to measure precise, accurate and model-independent stellar radii and stellar masses, so long as both components are spectroscopically resolved. Resolving both components is difficult in high-contrast binari... Read More about EBLM XV – Revised dynamical masses for the circumbinary planet host Kepler-16 AB, using the SOPHIE spectrograph.

Benchmark stars for mean stellar density and surface gravity estimates of solar-type stars (2025)
Journal Article
Maxted, P. F. L. (2025). Benchmark stars for mean stellar density and surface gravity estimates of solar-type stars. Monthly Notices of the Royal Astronomical Society, 539(4), 3741-3757. https://doi.org/10.1093/mnras/staf735

Adding an independent estimate of the mean stellar density, , as a constraint in the analysis of stars that host transiting exoplanets can significantly improve the precision of the planet radius estimate in cases where the light curve is too noisy t... Read More about Benchmark stars for mean stellar density and surface gravity estimates of solar-type stars.

A joint effort to discover and characterize two resonant mini-Neptunes around TOI-1803 with TESS, HARPS-N, and CHEOPS (2025)
Journal Article
Zingales, T., Malavolta, L., Borsato, L., Turrini, D., Bonfanti, A., Polychroni, D., Mantovan, G., Nardiello, D., Nascimbeni, V., Lanza, A. F., Bekkelien, A., Sozzetti, A., Broeg, C., Naponiello, L., Lendl, M., Bonomo, A. S., Simon, A. E., Desidera, S., Piotto, G., Mancini, L., …Winn, J. N. (2025). A joint effort to discover and characterize two resonant mini-Neptunes around TOI-1803 with TESS, HARPS-N, and CHEOPS. Astronomy & Astrophysics, 695(March 2025), Article A273. https://doi.org/10.1051/0004-6361/202451180

Context. The discovery and characterization of mini-Neptunes hold a potentially crucial impact on planetary formation and evolution theories. Estimating their orbital parameters and atmospheric properties would provide valuable hints to improve forma... Read More about A joint effort to discover and characterize two resonant mini-Neptunes around TOI-1803 with TESS, HARPS-N, and CHEOPS.

The EBLM project – XIV. TESS light curves for eclipsing binaries with very low mass companions (2025)
Journal Article
Fitzpatrick, J., Maxted, P. F. L., Freckelton, A. V., Triaud, A. H. M. J., Martin, D. V., & Duck, A. (in press). The EBLM project – XIV. TESS light curves for eclipsing binaries with very low mass companions. Monthly Notices of the Royal Astronomical Society, 537(4), 3943–3953. https://doi.org/10.1093/mnras/staf268

Accurate limb-darkening models are needed for accurate characterisation of eclipsing binary stars and transiting exoplanets from the analysis of their light curves. The limb-darkening observed in solar-type stars from the analysis of light curves for... Read More about The EBLM project – XIV. TESS light curves for eclipsing binaries with very low mass companions.

NGTS-EB-7, an eccentric, long-period, low-mass eclipsing binary (2024)
Journal Article
Rodel, T., Watson, C. A., Ulmer-Moll, S., Gill, S., Maxted, P. F. L., Casewell, S. L., Brahm, R., Wilson, T. G., Costes, J. C., Eschen, Y. N. E., Doyle, L., Freckelton, A. V., Alves, D. R., Apergis, I., Bayliss, D., Bouchy, F., Burleigh, M. R., Dumusque, X., Eberhardt, J., Fernández, J. F., …Wheatley, P. J. (in press). NGTS-EB-7, an eccentric, long-period, low-mass eclipsing binary. Monthly Notices of the Royal Astronomical Society, 1-22. https://doi.org/10.1093/mnras/stae2799

Despite being the most common types of stars in the Galaxy, the physical properties of late M dwarfs are often poorly constrained. A trend of radius inflation compared to evolutionary models has been observed for earlier type M dwarfs in eclipsing bi... Read More about NGTS-EB-7, an eccentric, long-period, low-mass eclipsing binary.

Architecture of TOI-561 planetary system (2024)
Journal Article
Piotto, G., Zingales, T., Borsato, L., Egger, J. A., Correia, A. C. M., Simon, A. E., Florén, H. .-G., Sousa, S. G., Maxted, P. F. L., Nardiello, D., Malavolta, L., Wilson, T. G., Alibert, Y., Adibekyan, V., Bonfanti, A., Luque, R., Santos, N. C., Hooton, M. J., Fossati, L., Smith, A. M. S., …Wolf, S. (in press). Architecture of TOI-561 planetary system. Monthly Notices of the Royal Astronomical Society, 535(3), 2763-2774. https://doi.org/10.1093/mnras/stae2440

We present new observations from CHEOPS (CHaracterising ExOPlanet Satellite) and TESS (Transiting Exoplanet Survey Satellite) to clarify the architecture of the planetary system hosted by the old Galactic thick disc star TOI-561. Our global analysis,... Read More about Architecture of TOI-561 planetary system.

Revised temperatures for two benchmark M-dwarfs – outliers no more (2024)
Journal Article
Martin, D. V., Armitage, T., Duck, A., Swayne, M. I., Martínez, R. R., Sethi, R., Stassun, K. G., Gaudi, B. S., Gill, S., Sebastian, D., & Maxted, P. F. L. (2024). Revised temperatures for two benchmark M-dwarfs – outliers no more. Monthly Notices of the Royal Astronomical Society, 1-10. https://doi.org/10.1093/mnras/stae2266

Well-characterised M-dwarfs are rare, particularly with respect to effective temperature. In this letter we re-analyse two benchmark M-dwarfs in eclipsing binaries from Kepler/K2: KIC 1571511AB and HD 24465AB. Both have temperatures reported to be ho... Read More about Revised temperatures for two benchmark M-dwarfs – outliers no more.

BEBOP VI. enabling the detection of circumbinary planets orbiting double-lined binaries with the DOLBY method of radial-velocity extraction (2024)
Journal Article
Sairam, L., Baycroft, T. A., Boisse, I., Heidari, N., Santerne, A., Triaud, A. H. M. J., Coleman, G. A. L., Davis, Y. T., Deleuil, M., Hébrard, G., Martin, D. V., Maxted, P. F. L., Nelson, R. P., Sebastian, D., Scutt, O. J., & Standing, M. R. (in press). BEBOP VI. enabling the detection of circumbinary planets orbiting double-lined binaries with the DOLBY method of radial-velocity extraction. Monthly Notices of the Royal Astronomical Society, 534(4), 3999-4017. https://doi.org/10.1093/mnras/stae2317

Circumbinary planets, orbiting both stars in a binary system, offer the opportunity to study planet formation and orbital migration in an environment different from that around single stars. However, despite the fact that $> 90~{{\%}}$ of binary s... Read More about BEBOP VI. enabling the detection of circumbinary planets orbiting double-lined binaries with the DOLBY method of radial-velocity extraction.

TOI–757 b: an eccentric transiting mini–Neptune on a 17.5–d orbit (2024)
Journal Article
Alqasim, A., Grieves, N., Rosário, N. M., Gandolfi, D., Livingston, J. H., Sousa, S., Collins, K. A., Teske, J. K., Fridlund, M., Egger, J. A., Cabrera, J., Hellier, C., Lanza, A. F., Van Eylen, V., Bouchy, F., Oelkers, R. J., Srdoc, G., Shectman, S., Günther, M., Goffo, E., …Yee, S. W. (2024). TOI–757 b: an eccentric transiting mini–Neptune on a 17.5–d orbit. Monthly Notices of the Royal Astronomical Society, 533(1), 1-26. https://doi.org/10.1093/mnras/stae1767

We report the spectroscopic confirmation and fundamental properties of TOI$-$757 b, a mini$-$Neptune on a 17.5$-$d orbit transiting a bright star ($V\, =\, 9.7$ mag) discovered by the TESS mission. We acquired high$-$precision radial velocity measure... Read More about TOI–757 b: an eccentric transiting mini–Neptune on a 17.5–d orbit.

CHEOPS in-flight performance: A comprehensive look at the first 3.5 yr of operations (2024)
Journal Article
Fortier, A., Simon, A. E., Broeg, C., Olofsson, G., Deline, A., Wilson, T. G., Maxted, P. F. L., Brandeker, A., Collier Cameron, A., Beck, M., Bekkelien, A., Billot, N., Bonfanti, A., Bruno, G., Cabrera, J., Delrez, L., Demory, B.-O., Futyan, D., Florén, H.-G., Günther, M. N., …Wolter, D. (2024). CHEOPS in-flight performance: A comprehensive look at the first 3.5 yr of operations. Astronomy & Astrophysics, 687, Article A302. https://doi.org/10.1051/0004-6361/202348576

Context. Since the discovery of the first exoplanet almost three decades ago, the number of known exoplanets has increased dramatically. By beginning of the 2000s it was clear that dedicated facilities to advance our studies in this field were needed... Read More about CHEOPS in-flight performance: A comprehensive look at the first 3.5 yr of operations.

HIP 41378 observed by CHEOPS: Where is planet d? (2024)
Journal Article
Sulis, S., Borsato, L., Grouffal, S., Osborn, H. P., Santerne, A., Brandeker, A., Günther, M. N., Heitzmann, A., Lendl, M., Fridlund, M., Gandolfi, D., Alibert, Y., Alonso, R., Bárczy, T., Barrado Navascues, D., Barros, S. C. C., Baumjohann, W., Beck, T., Benz, W., Bergomi, M., …Zingales, T. (2024). HIP 41378 observed by CHEOPS: Where is planet d?. Astronomy & Astrophysics, 686, Article L18. https://doi.org/10.1051/0004-6361/202449689

HIP 41378 d is a long-period planet that has only been observed to transit twice, three years apart, with K2. According to stability considerations and a partial detection of the Rossiter–McLaughlin effect, Pd = 278.36 d has been determined to be the... Read More about HIP 41378 observed by CHEOPS: Where is planet d?.

Detailed cool star flare morphology with CHEOPS and TESS (2024)
Journal Article
Bruno, G., Pagano, I., Scandariato, G., Florén, H.-G., Brandeker, A., Olofsson, G., Maxted, P. F. L., Fortier, A., Sousa, S. G., Sulis, S., Van Grootel, V., Garai, Z., Boldog, A., Kriskovics, L., Szabó, G. M., Gandolfi, D., Alibert, Y., Alonso, R., Bárczy, T., Barrado Navascues, D., …Wilson, T. G. (2024). Detailed cool star flare morphology with CHEOPS and TESS. Astronomy & Astrophysics, 686, Article A239. https://doi.org/10.1051/0004-6361/202348951

Context. White-light stellar flares are proxies for some of the most energetic types of flares, but their triggering mechanism is still poorly understood. As they are associated with strong X and ultraviolet emission, their study is particularly rele... Read More about Detailed cool star flare morphology with CHEOPS and TESS.

BEBOP V. Homogeneous stellar analysis of potential circumbinary planet hosts (2024)
Journal Article
Freckelton, A. V., Sebastian, D., Mortier, A., Triaud, A. H. M. J., Maxted, P. F. L., Acuña, L., Armstrong, D. J., Battley, M. P., Baycroft, T. A., Boisse, I., Bourrier, V., Carmona, A., Coleman, G. A. L., Cameron, A. C., Cortés-Zuleta, P., Delfosse, X., Dransfield, G., Duck, A., Forveille, T., French, J. R., …Willett, E. (2024). BEBOP V. Homogeneous stellar analysis of potential circumbinary planet hosts. Monthly Notices of the Royal Astronomical Society, 531(4), 4085-4098. https://doi.org/10.1093/mnras/stae1405

Planets orbiting binary systems are relatively unexplored compared to those around single stars. Detections of circumbinary planets and planetary systems offer a first detailed view into our understanding of circumbinary planet formation and dynamica... Read More about BEBOP V. Homogeneous stellar analysis of potential circumbinary planet hosts.

Seven new triply eclipsing triple star systems (2024)
Journal Article
Rappaport, S. A., Borkovits, T., Mitnyan, T., Gagliano, R., Eisner, N., Jacobs, T., Tokovinin, A., Powell, B., Kostov, V., Omohundro, M., Kristiansen, M. H., Jayaraman, R., Terentev, I., Schwengeler, H. M., LaCourse, D., Garai, Z., Pribulla, T., Maxted, P. F. L., Bíró, I. B., Csányi, I., …Vanderburg, A. (2024). Seven new triply eclipsing triple star systems. Astronomy & Astrophysics, 686(A27), https://doi.org/10.1051/0004-6361/202449273

Aims. We have identified nearly a hundred close triply eclipsing hierarchical triple star systems from data taken with the space telescope TESS. These systems are noteworthy in that we can potentially determine their dynamical and astrophysical param... Read More about Seven new triply eclipsing triple star systems.

An extended low-density atmosphere around the Jupiter-sized planet WASP-193 b (2024)
Journal Article
Barkaoui, K., Pozuelos, F. J., Hellier, C., Smalley, B., Nielsen, L. D., Niraula, P., Gillon, M., de Wit, J., Müller, S., Dorn, C., Helled, R., Jehin, E., Demory, B.-O., Van Grootel, V., Soubkiou, A., Ghachoui, M., Anderson, D. R., Benkhaldoun, Z., Bouchy, F., Burdanov, A., …West, R. G. (2024). An extended low-density atmosphere around the Jupiter-sized planet WASP-193 b. Nature Astronomy, https://doi.org/10.1038/s41550-024-02259-y

Gas giants transiting bright nearby stars provide crucial insights into planetary system formation and evolution mechanisms. Most of these planets show certain average characteristics, serving as benchmarks for our understanding of planetary systems.... Read More about An extended low-density atmosphere around the Jupiter-sized planet WASP-193 b.

The tidal deformation and atmosphere of WASP-12 b from its phase curve (2024)
Journal Article
Akinsanmi, B., Barros, S. C. C., Lendl, M., Carone, L., Cubillos, P. E., Bekkelien, A., Fortier, A., Florén, H.-G., Collier Cameron, A., Boué, G., Bruno, G., Demory, B.-O., Brandeker, A., Sousa, S. G., Wilson, T. G., Deline, A., Bonfanti, A., Scandariato, G., Hooton, M. J., Correia, A. C. M., …Walton, N. A. (2024). The tidal deformation and atmosphere of WASP-12 b from its phase curve. Astronomy & Astrophysics, 685, Article A63. https://doi.org/10.1051/0004-6361/202348502

Context. Ultra-hot Jupiters present a unique opportunity to understand the physics and chemistry of planets, their atmospheres, and interiors at extreme conditions. WASP-12 b stands out as an archetype of this class of exoplanets, with a close-in orb... Read More about The tidal deformation and atmosphere of WASP-12 b from its phase curve.

Discovery of two warm mini-Neptunes with contrasting densities orbiting the young K3V star TOI-815 (2024)
Journal Article
Psaridi, A., Osborn, H., Bouchy, F., Lendl, M., Parc, L., Billot, N., Broeg, C., Sousa, S. G., Adibekyan, V., Attia, O., Bonfanti, A., Chakraborty, H., Collins, K. A., Davoult, J., Delgado-Mena, E., Grieves, N., Guillot, T., Heitzmann, A., Helled, R., Hellier, C., …West, R. G. (2024). Discovery of two warm mini-Neptunes with contrasting densities orbiting the young K3V star TOI-815. Astronomy & Astrophysics, 685, Article A5. https://doi.org/10.1051/0004-6361/202348678

We present the discovery and characterization of two warm mini-Neptunes transiting the K-V star TOI-815 in a K-M binary system. Analysis of its spectra and rotation period reveal the star to be young, with an age of 200(-200)(+400) Myr. TOI-815b has... Read More about Discovery of two warm mini-Neptunes with contrasting densities orbiting the young K3V star TOI-815.

The EBLM Project XII. An eccentric, long-period eclipsing binary with a companion near the hydrogen-burning limit (2024)
Journal Article
Davis, Y. T., Triaud, A. H. M. J., Freckelton, A. V., Mortier, A., Brahm, R., Sebastian, D., Baycroft, T., Dransfield, G., Duck, A., Henning, T., Hobson, M. J., Jordán, A., Kunovac, V., Martin, D. V., Maxted, P. F. L., Sairam, L., Standing, M. R., Swayne, M. I., Trifonov, T., & Udry, S. (2024). The EBLM Project XII. An eccentric, long-period eclipsing binary with a companion near the hydrogen-burning limit. Monthly Notices of the Royal Astronomical Society, 530(3), https://doi.org/10.1093/mnras/stae842

In the hunt for Earth-like exoplanets it is crucial to have reliable host star parameters, as they have a direct impact on the accuracy and precision of the inferred parameters for any discovered exoplanet. For stars with masses between 0.35 and 0.5... Read More about The EBLM Project XII. An eccentric, long-period eclipsing binary with a companion near the hydrogen-burning limit.

The EBLM project – XIII. The absolute dynamical masses of the circumbinary planet host TOI-1338/BEBOP-1, and applications to the study of exoplanet atmospheres. (2024)
Journal Article
Sebastian, D., Triaud, A. H. M. J., Brogi, M., Baycroft, T. A., Standing, M. R., Maxted, P. F. L., Martin, D. V., Sairam, L., & Nielsen, M. B. (2024). The EBLM project – XIII. The absolute dynamical masses of the circumbinary planet host TOI-1338/BEBOP-1, and applications to the study of exoplanet atmospheres. Monthly Notices of the Royal Astronomical Society, 530(3), 2572–2589. https://doi.org/10.1093/mnras/stae459

High-contrast eclipsing binaries with low mass M-dwarf secondaries are precise benchmark stars to build empirical mass-radius relationships for fully convective low-mass ($\rm M_{\star } &lt; 0.35\, M_{\odot }$) dwarf stars. The contributed light... Read More about The EBLM project – XIII. The absolute dynamical masses of the circumbinary planet host TOI-1338/BEBOP-1, and applications to the study of exoplanet atmospheres..