Outputs (136)

GJ 3090 b: one of the most favourable mini-Neptune for atmospheric characterisation (2022)
Journal Article
Hellier. (2022). GJ 3090 b: one of the most favourable mini-Neptune for atmospheric characterisation. Astronomy & Astrophysics, https://doi.org/10.1051/0004-6361/202243975

We report the detection of GJ 3090 b (TOI-177.01), a mini-Neptune on a 2.9-day orbit transiting a bright (K = 7.3 mag) M2 dwarf located at 22 pc. The planet was identified by the Transiting Exoplanet Survey Satellite and was confirmed with the High A... Read More about GJ 3090 b: one of the most favourable mini-Neptune for atmospheric characterisation.

The HD 260655 system: Two rocky worlds transiting a bright M dwarf at 10 pc (2022)
Journal Article
Hellier. (2022). The HD 260655 system: Two rocky worlds transiting a bright M dwarf at 10 pc. Astronomy & Astrophysics, 1 - 23. https://doi.org/10.1051/0004-6361/202243834

We report the discovery of a multiplanetary system transiting the M0 V dwarf HD 260655 (GJ 239, TOI-4599). The system consists of at least two transiting planets, namely HD 260655 b, with a period of 2.77 d, a radius of Rb = 1.240 ± 0.023 R?, a mass... Read More about The HD 260655 system: Two rocky worlds transiting a bright M dwarf at 10 pc.

TOI-712: A System of Adolescent Mini-Neptunes Extending to the Habitable Zone (2022)
Journal Article
Hellier. (2022). TOI-712: A System of Adolescent Mini-Neptunes Extending to the Habitable Zone. Astronomical Journal, https://doi.org/10.3847/1538-3881/ac7954

As an all-sky survey, NASA's Transiting Exoplanet Survey Satellite (TESS) mission is able to detect the brightest and rarest types of transiting planetary systems, including young planets that enable study of the evolutionary processes that occur wit... Read More about TOI-712: A System of Adolescent Mini-Neptunes Extending to the Habitable Zone.

The young HD 73583 (TOI-560) planetary system: two 10-M-circle plus mini-Neptunes transiting a 500-Myr-old, bright, and active K dwarf (2022)
Journal Article
Hellier. (2022). The young HD 73583 (TOI-560) planetary system: two 10-M-circle plus mini-Neptunes transiting a 500-Myr-old, bright, and active K dwarf. Monthly Notices of the Royal Astronomical Society, 1606 - 1627. https://doi.org/10.1093/mnras/stac638

We present the discovery and characterization of two transiting planets observed by TESS in the light curves of the young and bright (V = 9.67) star HD73583 (TOI-560). We perform an intensive spectroscopic and photometric space- and ground-based foll... Read More about The young HD 73583 (TOI-560) planetary system: two 10-M-circle plus mini-Neptunes transiting a 500-Myr-old, bright, and active K dwarf.

BEBOP II: sensitivity to sub-Saturn circumbinary planets using radial-velocities (2022)
Journal Article
Maxted, & Hellier. (2022). BEBOP II: sensitivity to sub-Saturn circumbinary planets using radial-velocities. Monthly Notices of the Royal Astronomical Society, 3571 - 3583. https://doi.org/10.1093/mnras/stac113

BEBOP is a radial-velocity survey that monitors a sample of single-lined eclipsing binaries, in search of circumbinary planets by using high-resolution spectrographs. Here, we describe and test the methods we use to identify planetary signals within... Read More about BEBOP II: sensitivity to sub-Saturn circumbinary planets using radial-velocities.

TOI-1201 b: A mini-Neptune transiting a bright and moderately young M dwarf (2021)
Journal Article
Hellier. (2021). TOI-1201 b: A mini-Neptune transiting a bright and moderately young M dwarf. Astronomy & Astrophysics, https://doi.org/10.1051/0004-6361/202141587

We present the discovery of a transiting mini-Neptune around TOI-1201, a relatively bright and moderately young early M dwarf (J ˜ 9.5 mag, ~600–800 Myr) in an equal-mass ~8 arcsecond-wide binary system, using data from the Transiting Exoplanet Surve... Read More about TOI-1201 b: A mini-Neptune transiting a bright and moderately young M dwarf.

GJ 367b: A dense, ultrashort-period sub-Earth planet transiting a nearby red dwarf star. (2021)
Journal Article
Hellier. (2021). GJ 367b: A dense, ultrashort-period sub-Earth planet transiting a nearby red dwarf star. Science, 1271 - 1275. https://doi.org/10.1126/science.aay3253

Ultrashort-period (USP) exoplanets have orbital periods shorter than 1 day. Precise masses and radii of USP exoplanets could provide constraints on their unknown formation and evolution processes. We report the detection and characterization of the U... Read More about GJ 367b: A dense, ultrashort-period sub-Earth planet transiting a nearby red dwarf star..

TIC 172900988: A Transiting Circumbinary Planet Detected in One Sector of TESS Data (2021)
Journal Article
Hellier, & Maxted. (2021). TIC 172900988: A Transiting Circumbinary Planet Detected in One Sector of TESS Data. Astronomical Journal, https://doi.org/10.3847/1538-3881/ac223a

We report the first discovery of a transiting circumbinary planet detected from a single sector of Transiting Exoplanet Survey Satellite (TESS) data. During Sector 21, the planet TIC 172900988b transited the primary star and then five days later it t... Read More about TIC 172900988: A Transiting Circumbinary Planet Detected in One Sector of TESS Data.

The EBLM project - VIII. First results for M-dwarf mass, radius, and effective temperature measurements using CHEOPS light curves (2021)
Journal Article
Hellier, & Maxted. (2021). The EBLM project - VIII. First results for M-dwarf mass, radius, and effective temperature measurements using CHEOPS light curves. Monthly Notices of the Royal Astronomical Society, 306 - 322. https://doi.org/10.1093/mnras/stab1687

The accuracy of theoretical mass, radius, and effective temperature values for M-dwarf stars is an active topic of debate. Differences between observed and theoretical values have raised the possibility that current theoretical stellar structure and... Read More about The EBLM project - VIII. First results for M-dwarf mass, radius, and effective temperature measurements using CHEOPS light curves.

TOI-431/HIP 26013: a super-Earth and a sub-Neptune transiting a bright, early K dwarf, with a third RV planet (2021)
Journal Article
Osborn, A., Armstrong, D. J., Cale, B., Brahm, R., Wittenmyer, R. A., Dai, F., …Zohrabi, F. (2021). TOI-431/HIP 26013: a super-Earth and a sub-Neptune transiting a bright, early K dwarf, with a third RV planet. Monthly Notices of the Royal Astronomical Society, 507(2), 2782 - 2803. https://doi.org/10.1093/mnras/stab2313

We present the bright (Vmag = 9.12), multiplanet system TOI-431, characterized with photometry and radial velocities (RVs). We estimate the stellar rotation period to be 30.5 ± 0.7 d using archival photometry and RVs. Transiting Exoplanet Survey Sate... Read More about TOI-431/HIP 26013: a super-Earth and a sub-Neptune transiting a bright, early K dwarf, with a third RV planet.