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., …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., Sulis, S., Valdes, E., Brandeker, A., Billot, N., …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., …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.

REDISCUSSION OF ECLIPSING BINARIES. PAPER 11: ZZ URSAE MAJORIS, A SOLAR-TYPE SYSTEM SHOWING TOTAL ECLIPSES AND A RADIUS DISCREPANCY (2022)
Journal Article
Taylor, J. (2022). REDISCUSSION OF ECLIPSING BINARIES. PAPER 11: ZZ URSAE MAJORIS, A SOLAR-TYPE SYSTEM SHOWING TOTAL ECLIPSES AND A RADIUS DISCREPANCY. Observatory, 142, 267 - 284. https://doi.org/10.48550/arXiv.2209.10384

Fundamental effective temperature measurements for eclipsing binary stars (2022)
Thesis
Miller, N. J. (2022). Fundamental effective temperature measurements for eclipsing binary stars. (Thesis). Keele University

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.

δ Scuti pulsations in the bright Pleiades eclipsing binary HD 23642 (2022)
Journal Article
Southworth, J., Murphy, S. J., & Pavlovski, K. (2022). δ Scuti pulsations in the bright Pleiades eclipsing binary HD 23642. Monthly Notices of the Royal Astronomical Society: Letters, 520(1), L53-L57. https://doi.org/10.1093/mnrasl/slad004

We announce the discovery of pulsations in HD?23642, the only bright eclipsing system in the Pleiades, based on light curves from the Transiting Exoplanet Survey Satellite (TESS). We measure 46 pulsation frequencies and attribute them to d?Scuti puls... Read More about δ Scuti pulsations in the bright Pleiades eclipsing binary HD 23642.

Phase curve and geometric albedo of WASP-43b measured with CHEOPS, TESS, and HST WFC3/UVIS (2022)
Journal Article
Maxted. (2022). Phase curve and geometric albedo of WASP-43b measured with CHEOPS, TESS, and HST WFC3/UVIS. Astronomy & Astrophysics, https://doi.org/10.1051/0004-6361/202243974

Context. Observations of the phase curves and secondary eclipses of extrasolar planets provide a window onto the composition and thermal structure of the planetary atmospheres. For example, the photometric observations of secondary eclipses lead to t... Read More about Phase curve and geometric albedo of WASP-43b measured with CHEOPS, TESS, and HST WFC3/UVIS.

Discovery of TOI-1260d and the characterization of the multiplanet system (2022)
Journal Article
Lam, K. W. F., Cabrera, J., Hooton, M. J., Alibert, Y., Bonfanti, A., Beck, M., …Winn., J. N. (2023). Discovery of TOI-1260d and the characterization of the multiplanet system. Monthly Notices of the Royal Astronomical Society, 519(1), 1437 - 1451. https://doi.org/10.1093/mnras/stac3639

We report the discovery of a third planet transiting the star TOI-1260, previously known to host two transiting sub-Neptune planets with orbital periods of 3.127 and 7.493 d, respectively. The nature of the third transiting planet with a 16.6-d orbit... Read More about Discovery of TOI-1260d and the characterization of the multiplanet system.

A CHEOPS-enhanced view of the HD 3167 system (2022)
Journal Article
Bourrier, V., Deline, A., Krenn, A., Egger, J., Petit, A., Malavolta, L., …Viotto, V. (2022). A CHEOPS-enhanced view of the HD 3167 system. Astronomy & Astrophysics, https://doi.org/10.1051/0004-6361/202243778

Much remains to be understood about the nature of exoplanets smaller than Neptune, most of which have been discovered in compact multi-planet systems. With its inner ultra-short period planet b aligned with the star and two larger outer planets d-c o... Read More about A CHEOPS-enhanced view of the HD 3167 system.

Characterization of the HD 108236 system with CHEOPS and TESS Confirmation of a fifth transiting planet (2022)
Journal Article
Maxted. (2022). Characterization of the HD 108236 system with CHEOPS and TESS Confirmation of a fifth transiting planet. Astronomy & Astrophysics, https://doi.org/10.1051/0004-6361/202243720

Context. The HD 108236 system was first announced with the detection of four small planets based on TESS data. Shortly after, the transit of an additional planet with a period of 29.54 d was serendipitously detected by CHEOPS. In this way, HD 108236... Read More about Characterization of the HD 108236 system with CHEOPS and TESS Confirmation of a fifth transiting planet.

The VLT-FLAMES Tarantula Survey Observational evidence for two distinct populations of massive runaway stars in 30 Doradus (2022)
Journal Article
Observational evidence for two distinct populations of massive runaway stars in 30 Doradus. Astronomy & Astrophysics, https://doi.org/10.1051/0004-6361/202244677

Context. The origin of massive runaway stars is an important unsolved problem in astrophysics. Two main scenarios have been proposed, namely: dynamical ejection or release from a binary at the first core collapse. However, their relative contribution... Read More about The VLT-FLAMES Tarantula Survey Observational evidence for two distinct populations of massive runaway stars in 30 Doradus.

Estimating the Convective Turnover Time (2022)
Journal Article
Wright. (2022). Estimating the Convective Turnover Time. Astrophysical Journal, 1-6. https://doi.org/10.3847/1538-4357/ac9cd8

The introduction of the Rossby number (R0), which incorporates the convective turnover time (t), in 1984 was a pioneering idea for understanding the correlation between stellar rotation and activity. The convective turnover time, which cannot be meas... Read More about Estimating the Convective Turnover Time.

The structure and 3D kinematics of vela OB2 (2022)
Journal Article
Armstrong, J. J., Wright, N. J., Jeffries, R. D., Jackson, R. J., & Cantat-Gaudin, T. (2022). The structure and 3D kinematics of vela OB2. Monthly Notices of the Royal Astronomical Society, 517(4), 5704 - 5720. https://doi.org/10.1093/mnras/stac3101

The kinematics of stars in OB associations can provide insights into their formation, dynamical evolution, and eventual fate. The low-mass stellar content of OB associations are sufficiently numerous as to provide a detailed sampling of their kinemat... Read More about The structure and 3D kinematics of vela OB2.

VLT, GROND, AND DANISH TELESCOPE OBSERVATIONS OF TRANSITS IN THE TRAPPIST-I SYSTEM (2022)
Journal Article
Southworth, J., Mancini, L., Dominik, M., Jørgensen, U., Bozza, V., Burgdorf, M., …Snodgrass, C. (2022). VLT, GROND, AND DANISH TELESCOPE OBSERVATIONS OF TRANSITS IN THE TRAPPIST-I SYSTEM. Observatory, 142, 220 - 229

TRAPPIST-1 is an ultra-cool dwarf that hosts seven known transiting planets. We present photometry of the system obtained using three telescopes at ESO La Silla (the Danish 1.54 m telescope and the 2.2 m MPI telescope) and Paranal (Unit Telescope 1 o... Read More about VLT, GROND, AND DANISH TELESCOPE OBSERVATIONS OF TRANSITS IN THE TRAPPIST-I SYSTEM.

The GAPS programme at TNG XL. A puffy and warm Neptune-sized planet and an outer Neptune-mass candidate orbiting the solar-type star TOI-1422 (2022)
Journal Article
Hellier. (2022). The GAPS programme at TNG XL. A puffy and warm Neptune-sized planet and an outer Neptune-mass candidate orbiting the solar-type star TOI-1422. Astronomy & Astrophysics, https://doi.org/10.1051/0004-6361/202244079

Context. Neptunes represent one of the main types of exoplanets and have chemical-physical characteristics halfway between rocky and gas giant planets. Therefore, their characterization is important for understanding and constraining both the formati... Read More about The GAPS programme at TNG XL. A puffy and warm Neptune-sized planet and an outer Neptune-mass candidate orbiting the solar-type star TOI-1422.

Internal mixing processes in massive stars: uncertainties and impact (2022)
Thesis
Kaiser, E. (2022). Internal mixing processes in massive stars: uncertainties and impact. (Thesis). Keele University

Massive stars are key contributors to the evolution of galaxies and many observed phenomena. Therefore, understanding them is crucial to explain the evolution of the Universe and its constituents. The evolution of massive stars is strongly in uenced... Read More about Internal mixing processes in massive stars: uncertainties and impact.