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TOI-4562b: A Highly Eccentric Temperate Jupiter Analog Orbiting a Young Field Star (2023)
Journal Article
Hellier. (2023). TOI-4562b: A Highly Eccentric Temperate Jupiter Analog Orbiting a Young Field Star. Astronomical Journal, https://doi.org/10.3847/1538-3881/acb5a2

We report the discovery of TOI-4562b (TIC-349576261), a Jovian planet orbiting a young F7V-type star, younger than the Praesepe/Hyades clusters (<700 Myr). This planet stands out because of its unusually long orbital period for transiting planets wit...

Hint of an exocomet transit in the CHEOPS light curve of HD 172555 (2023)
Journal Article
Maxted. (2023). Hint of an exocomet transit in the CHEOPS light curve of HD 172555. Astronomy & Astrophysics, https://doi.org/10.1051/0004-6361/202245104

HD 172555 is a young (~20 Myr) A7V star surrounded by a 10 au wide debris disk suspected to be replenished partly by collisions between large planetesimals. Small evaporating transiting bodies, that is exocomets, have also been detected in this syste... Read More about Hint of an exocomet transit in the CHEOPS light curve of HD 172555.

The Gaia-ESO Survey: Preparing the ground for 4MOST and WEAVE galactic surveys (2023)
Journal Article
Nepal, S., Guiglion, G., de Jong, R., Valentini, M., Chiappini, C., Steinmetz, M., Ambrosch, M., Pancino, E., Jeffries, R., Bensby, T., Romano, D., Smiljanic, R., Dantas, M., Gilmore, G., Randich, S., Bayo, A., Bergemann, M., Franciosini, E., Jiménez-Esteban, F., Jofré, P., …Zaggia, S. (2023). The Gaia-ESO Survey: Preparing the ground for 4MOST and WEAVE galactic surveys. Astronomy & Astrophysics, 671, Article A61. https://doi.org/10.1051/0004-6361/202244765

Context. Originating from several sources (Big Bang, stars, cosmic rays) and being strongly depleted during stellar lifetime, the lithium element is of great interest as its chemical evolution in the Milky Way is not yet well understood. To help cons... Read More about The Gaia-ESO Survey: Preparing the ground for 4MOST and WEAVE galactic surveys.

On ρ-conjugate Hopf–Galois structures (2023)
Journal Article
Truman. (2023). On ρ-conjugate Hopf–Galois structures. Proceedings of the Edinburgh Mathematical Society, 66(1), 288-304. https://doi.org/10.1017/S0013091523000184

The Hopf-Galois structures admitted by a Galois extension of fields $ L/K $ with Galois group $ G $ correspond bijectively with certain subgroups of $ \mathrm{Perm}(G) $. We use a natural partition of the set of such subgroups to obtain a method for... Read More about On ρ-conjugate Hopf–Galois structures.

A precise blue-optical transmission spectrum from the ground: evidence for haze in the atmosphere of WASP-74b (2023)
Journal Article
Spyratos, P., Nikolov, N. K., Constantinou, S., Southworth, J., Madhusudhan, N., Sedaghati, E., Ehrenreich, D., & Mancini, L. (2023). A precise blue-optical transmission spectrum from the ground: evidence for haze in the atmosphere of WASP-74b. Monthly Notices of the Royal Astronomical Society, 521(2), 2163 - 2180. https://doi.org/10.1093/mnras/stad637

We report transmission spectroscopy of the bloated hot Jupiter WASP-74b in the wavelength range from 4000 to 6200 Å. We observe two transit events with the Very Large Telescope (VLT) Focal Reducer and Spectrograph and present a new method to measure... Read More about A precise blue-optical transmission spectrum from the ground: evidence for haze in the atmosphere of WASP-74b.

The EBLM project X. benchmark masses, radii and temperatures for two fully convective M-dwarfs using K2 (2023)
Journal Article
Duck, A., Martin, D. V., Gill, S., Armitage, T., Rodríguez Martínez, R., Maxted, P. F. L., Sebastian, D., Sethi, R., Swayne, M. I., Cameron, A. C., Dransfield, G., Gaudi, B. S., Gillon, M., Hellier, C., Kunovac, V., Lovis, C., McCormac, J., Pepe, F. A., Pollacco, D., Sairam, L., …Udry, S. (2023). The EBLM project X. benchmark masses, radii and temperatures for two fully convective M-dwarfs using K2. Monthly Notices of the Royal Astronomical Society, 521(4), 6305-6317. https://doi.org/10.1093/mnras/stad452

M-dwarfs are the most abundant stars in the galaxy and popular targets for exoplanet searches. However, their intrinsic faintness and complex spectra inhibit precise characterisation. We only know of dozens of M-dwarfs with fundamental parameters of... Read More about The EBLM project X. benchmark masses, radii and temperatures for two fully convective M-dwarfs using K2.

Revising the properties of low mass eclipsing binary stars using TESS light curves (2023)
Journal Article
Jennings, Z., Southworth, J., Maxted, P. F. L., & Mancini, L. (2023). Revising the properties of low mass eclipsing binary stars using TESS light curves. Monthly Notices of the Royal Astronomical Society, 521(3), 3405-3420. https://doi.org/10.1093/mnras/stad519

Precise measurements of stellar parameters are required in order to develop our theoretical understanding of stellar structure. These measurements enable errors and uncertainties to be quantified in theoretical models and constrain the physical inter... Read More about Revising the properties of low mass eclipsing binary stars using TESS light curves.

H I filaments as potential compass needles? Comparing the magnetic field structure of the Small Magellanic Cloud to the orientation of GASKAP-H I filaments (2023)
Journal Article
Van Loon, J. T., Ma, Y. K., McClure-Griffiths, N. M., Clark, S. E., Gibson, S. J., Soler, J. D., Putman, M. E., Dickey, J. M., Lee, M. .-Y., Jameson, K. E., Uscanga, L., Dempsey, J., Dénes, H., Lynn, C., & Pingel, N. M. (2023). H I filaments as potential compass needles? Comparing the magnetic field structure of the Small Magellanic Cloud to the orientation of GASKAP-H I filaments. Monthly Notices of the Royal Astronomical Society, 521(1), 60 - 83. https://doi.org/10.1093/mnras/stad462

High-spatial-resolution H i observations have led to the realization that the nearby (within few hundreds of parsecs) Galactic atomic filamentary structures are aligned with the ambient magnetic field. Enabled by the high-quality data from the Austra... Read More about H I filaments as potential compass needles? Comparing the magnetic field structure of the Small Magellanic Cloud to the orientation of GASKAP-H I filaments.

TOI-836: A super-Earth and mini-Neptune transiting a nearby K-dwarf (2023)
Journal Article
Hawthorn, F., Bayliss, D., Wilson, T. G., Bonfanti, A., Adibekyan, V., Alibert, Y., Sousa, S. G., Collins, K. A., Bryant, E. M., Osborn, A., Armstrong, D. J., Abe, L., Acton, J. S., Addison, B. C., Agabi, K., Alonso, R., Alves, D. R., Anglada-Escudé, G., Bárczy, T., Barclay, T., …Zhang, H. (2023). TOI-836: A super-Earth and mini-Neptune transiting a nearby K-dwarf. Monthly Notices of the Royal Astronomical Society, 520(3), 3649 - 3668. https://doi.org/10.1093/mnras/stad306

We present the discovery of two exoplanets transiting TOI-836 (TIC 440887364) using data from TESS Sector 11 and Sector 38. TOI-836 is a bright (T = 8.5?mag), high proper motion (~200?mas?yr-1), low metallicity ([Fe/H]˜-0.28) K-dwarf with a mass of 0... Read More about TOI-836: A super-Earth and mini-Neptune transiting a nearby K-dwarf.

Connecting photometric and spectroscopic granulation signals with CHEOPS and ESPRESSO (2023)
Journal Article
Maxted. (2023). Connecting photometric and spectroscopic granulation signals with CHEOPS and ESPRESSO. Astronomy & Astrophysics, https://doi.org/10.1051/0004-6361/202244223

Context. Stellar granulation generates fluctuations in photometric and spectroscopic data whose properties depend on the stellar type, composition, and evolutionary state. Characterizing granulation is key for understanding stellar atmospheres and de... Read More about Connecting photometric and spectroscopic granulation signals with CHEOPS and ESPRESSO.

TOI-1075 b: A Dense, Massive, Ultra-short-period Hot Super-Earth Straddling the Radius Gap (2023)
Journal Article
Hellier. (2023). TOI-1075 b: A Dense, Massive, Ultra-short-period Hot Super-Earth Straddling the Radius Gap. Astronomical Journal, https://doi.org/10.3847/1538-3881/ac9c5b

Populating the exoplanet mass–radius diagram in order to identify the underlying relationship that governs planet composition is driving an interdisciplinary effort within the exoplanet community. The discovery of hot super-Earths—a high-temperature,... Read More about TOI-1075 b: A Dense, Massive, Ultra-short-period Hot Super-Earth Straddling the Radius Gap.

Transit timing variation analysis of the low-mass brown dwarf KELT-1 b (2023)
Journal Article
Baştürk, Ö., Taylor, J., Yalçınkaya, S., Mancini, L., Esmer, E., Tekin, M., Tezcan, F., Evans, D., Tezcan, C., Bruni, I., & Yeşilyaprak, C. (2023). Transit timing variation analysis of the low-mass brown dwarf KELT-1 b. Monthly Notices of the Royal Astronomical Society, 521(1), 1200-1209. https://doi.org/10.1093/mnras/stad248

We investigate whether there is a variation in the orbital period of the short-period brown dwarf-mass KELT-1 b, which is one of the best candidates to observe orbital decay. We obtain 19 high-precision transit light curves of the target using six di... Read More about Transit timing variation analysis of the low-mass brown dwarf KELT-1 b.

TOI-969: a late-K dwarf with a hot mini-Neptune in the desert and an eccentric cold Jupiter (2023)
Journal Article
Hellier. (2023). TOI-969: a late-K dwarf with a hot mini-Neptune in the desert and an eccentric cold Jupiter. Astronomy & Astrophysics, https://doi.org/10.1051/0004-6361/202243879

Context. The current architecture of a given multi-planetary system is a key fingerprint of its past formation and dynamical evolution history. Long-term follow-up observations are key to complete their picture. Aims. In this paper, we focus on the c... Read More about TOI-969: a late-K dwarf with a hot mini-Neptune in the desert and an eccentric cold Jupiter.

Examining the orbital decay targets KELT-9 b, KELT-16 b, and WASP-4 b, and the transit-timing variations of HD 97658 b (2023)
Journal Article
Maxted, P., & Hellier, C. (2023). Examining the orbital decay targets KELT-9 b, KELT-16 b, and WASP-4 b, and the transit-timing variations of HD 97658 b. Astronomy & Astrophysics, 669, Article A124. https://doi.org/10.1051/0004-6361/202244529

Context. Tidal orbital decay is suspected to occur for hot Jupiters in particular, with the only observationally confirmed case of this being WASP-12b. By examining this effect, information on the properties of the host star can be obtained using the... Read More about Examining the orbital decay targets KELT-9 b, KELT-16 b, and WASP-4 b, and the transit-timing variations of HD 97658 b.

55 Cancri e's occultation captured with CHEOPS (2023)
Journal Article
Matthews, P., Demory, B.-O., Sulis, S., Valdes, E., Brandeker, A., Billot, N., Fortier, A., Hoyer, S., Sousa, S., Heng, K., Lendl, M., Krenn, A., Morris, B., Patel, J., Alibert, Y., Alonso, R., Delrez, L., Anglada, G., Broeg, C., Buder, M., …Walton, N. (2023). 55 Cancri e's occultation captured with CHEOPS. Astronomy & Astrophysics, https://doi.org/10.1051/0004-6361/202244894

Past occultation and phase-curve observations of the ultra-short period super-Earth 55 Cnc e obtained at visible and infrared wavelengths have been challenging to reconcile with a planetary reflection and emission model. In this study, we analyse a s... Read More about 55 Cancri e's occultation captured with CHEOPS.

Early Release Science of the exoplanet WASP-39b with JWST NIRSpec PRISM (2023)
Journal Article
Rustamkulov, Z., Sing, D. K., Mukherjee, S., May, E. M., Kirk, J., Schlawin, E., Line, M. R., Piaulet, C., Carter, A. L., Batalha, N. E., Goyal, J. M., López-Morales, M., Lothringer, J. D., MacDonald, R. J., Moran, S. E., Stevenson, K. B., Wakeford, H. R., Espinoza, N., Bean, J. L., Batalha, N. M., …Zieba, S. (2023). Early Release Science of the exoplanet WASP-39b with JWST NIRSpec PRISM. Nature, 614, 659–663. https://doi.org/10.1038/s41586-022-05677-y

Transmission spectroscopy1,2,3 of exoplanets has revealed signatures of water vapor, aerosols, and alkali metals in a few dozen exoplanet atmospheres4,5. However, these previous inferences with the Hubble and Spitzer Space Telescopes were hindered by... Read More about Early Release Science of the exoplanet WASP-39b with JWST NIRSpec PRISM.

The Isaac Newton Telescope Monitoring Survey of Local Group Dwarf Galaxies. V. The Star Formation History of Sagittarius Dwarf Irregular Galaxy Derived from Long-period Variable Stars (2023)
Journal Article
Van Loon, J. (2023). The Isaac Newton Telescope Monitoring Survey of Local Group Dwarf Galaxies. V. The Star Formation History of Sagittarius Dwarf Irregular Galaxy Derived from Long-period Variable Stars. Astrophysical Journal, https://doi.org/10.3847/1538-4357/aca471

We conducted an optical monitoring survey of the Sagittarius dwarf irregular galaxy (SagDIG) during the period of 2016 June–2017 October, using the 2.5 m Isaac Newton Telescopeat La Palama. Our goal was to identify long-period variable stars (LPVs),... Read More about The Isaac Newton Telescope Monitoring Survey of Local Group Dwarf Galaxies. V. The Star Formation History of Sagittarius Dwarf Irregular Galaxy Derived from Long-period Variable Stars.

TOI 560: Two Transiting Planets Orbiting a K Dwarf Validated with iSHELL, PFS, and HIRES RVs (2023)
Journal Article
Hellier. (2023). TOI 560: Two Transiting Planets Orbiting a K Dwarf Validated with iSHELL, PFS, and HIRES RVs. Astronomical Journal, https://doi.org/10.3847/1538-3881/ac9834

We validate the presence of a two-planet system orbiting the 0.15–1.4 Gyr K4 dwarf TOI 560 (HD 73583). The system consists of an inner moderately eccentric transiting mini-Neptune (TOI 560 b, $P={6.3980661}_{-0.0000097}^{+0.0000095}$ days, $e={0.294}... Read More about TOI 560: Two Transiting Planets Orbiting a K Dwarf Validated with iSHELL, PFS, and HIRES RVs.

Fundamental effective temperature measurements for eclipsing binary stars (2022)
Thesis
Miller, N. J. Fundamental effective temperature measurements for eclipsing binary stars. (Thesis). Keele University. https://keele-repository.worktribe.com/output/425030

Modern high-precision spectroscopy and photometry has made it possible to directly measure masses and radii for stars in detached eclipsing binaries (DEBs) to 0.5% or better. These stars, due to their wide orbits, are suitable for testing models of s... Read More about Fundamental effective temperature measurements for eclipsing binary stars.