Outputs (135)

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.

Warm Jupiters in TESS Full-frame Images: A Catalog and Observed Eccentricity Distribution for Year 1 (2021)
Journal Article
Hellier. (2021). Warm Jupiters in TESS Full-frame Images: A Catalog and Observed Eccentricity Distribution for Year 1. Astrophysical Journal, https://doi.org/10.3847/1538-4365/abf73c

Warm Jupiters—defined here as planets larger than 6 Earth radii with orbital periods of 8–200 days—are a key missing piece in our understanding of how planetary systems form and evolve. It is currently debated whether Warm Jupiters form in situ, unde... Read More about Warm Jupiters in TESS Full-frame Images: A Catalog and Observed Eccentricity Distribution for Year 1.

A hot mini-Neptune in the radius valley orbiting solar analogue HD 110113 (2021)
Journal Article
Hellier. (2021). A hot mini-Neptune in the radius valley orbiting solar analogue HD 110113. Monthly Notices of the Royal Astronomical Society, 4842 - 4857. https://doi.org/10.1093/mnras/stab182

We report the discovery of HD?110113?b (TESS object of interest-755.01), a transiting mini-Neptune exoplanet on a 2.5-d orbit around the solar-analogue HD?110113 (Teff = 5730 K). Using TESS photometry and High Accuracy Radial velocity Planet Searcher... Read More about A hot mini-Neptune in the radius valley orbiting solar analogue HD 110113.

A nearby transiting rocky exoplanet that is suitable for atmospheric investigation. (2021)
Journal Article
Hellier. (2021). A nearby transiting rocky exoplanet that is suitable for atmospheric investigation. Science, 1038 - 1041. https://doi.org/10.1126/science.abd7645

Spectroscopy of transiting exoplanets can be used to investigate their atmospheric properties and habitability. Combining radial velocity (RV) and transit data provides additional information on exoplanet physical properties. We detect a transiting r... Read More about A nearby transiting rocky exoplanet that is suitable for atmospheric investigation..

TESS Discovery of a Super-Earth and Three Sub-Neptunes Hosted by the Bright, Sun-like Star HD 108236 (2021)
Journal Article
Hellier. (2021). TESS Discovery of a Super-Earth and Three Sub-Neptunes Hosted by the Bright, Sun-like Star HD 108236. Astronomical Journal, https://doi.org/10.3847/1538-3881/abd73e

We report the discovery and validation of four extrasolar planets hosted by the nearby, bright, Sun-like (G3V) star HD 108236 using data from the Transiting Exoplanet Survey Satellite (TESS). We present transit photometry, reconnaissance, and precise... Read More about TESS Discovery of a Super-Earth and Three Sub-Neptunes Hosted by the Bright, Sun-like Star HD 108236.