New planetary systems from the Calan–Hertfordshire Extrasolar Planet Search

Jenkins, James S.; Jones, H. R. A.; Tuomi, Mikko; Díaz, Matías R.; Cordero, J.; Aguayo, A.; Pantoja, B.; Arriagada, P.; Mahu, Rodrigo; Brahm, R.; Rojo, P.; Soto, M. G.; Ivanyuk, O.; Yoma, Néstor Becerra; Day-Jones, A. C.; Ruíz, M. T.; Pavlenko, Ya. V.; Barnes, John; Murgas, F.; Pinfield, D. J.; Jones, M. I.; López‐Morales, Mercedes; Shectman, Stephen; Butler, R. Paul; Minniti, D.

doi:10.1093/mnras/stw2811

Cited by 73 publications

(24 citation statements)

References 88 publications

(104 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Yet, some features were also in agreement with stud-ies of planets orbiting more massive stars. Gas giant planets have been found in higher abundance orbiting Sunlike stars (Fischer & Valenti 2005;Adibekyan et al 2012;Jenkins et al 2017), and this bias appears to hold down into the M dwarf regime also (Schlaufman & Laughlin 2010;Rojas-Ayala et al 2010;Montes et al 2018).…”

Section: Introductionmentioning

confidence: 99%

GJ 357: a low-mass planetary system uncovered by precision radial velocities and dynamical simulations

Jenkins

Pozuelos

Tuomi

et al. 2019

Monthly Notices of the Royal Astronomical Society

View full text Add to dashboard Cite

We report the detection of a new planetary system orbiting the nearby M2.5V star GJ 357, using precision radial-velocities from three separate echelle spectrographs, HARPS, HiRES, and UVES. Three small planets have been confirmed in the system, with periods of 9.125±0.001, 3.9306±0.0003, and 55.70±0.05 days, and minimum masses of 3.33±0.48, 2.09±0.32, and 6.72±0.94 M ⊕ , respectively. The second planet in our system, GJ 357c, was recently shown to transit by the Transiting Exoplanet Survey Satellite (TESS; Luque et al. 2019), but we could find no transit signatures for the other two planets. Dynamical analysis reveals the system is likely to be close to coplanar, is stable on Myrs timescales, and places strong upper limits on the masses of the two non-transiting planets b and d of 4.25 and 11.20 M ⊕ , respectively. Therefore, we confirm the system contains at least two super-Earths, and either a third super-Earth or mini-Neptune planet. GJ 357b & c are found to be close to a 7:3 mean motion resonance, however no libration of the orbital parameters was found in our simulations. Analysis of the photometric lightcurve of the star from the TESS, when combined with our radial-velocities, reveal GJ 357c has an absolute mass, radius, and density of 2.248 +0.117 −0.120 M ⊕ , 1.167 +0.037 −0.036 R ⊕ , and 7.757 +0.889 −0.789 gcm −3 , respectively. Comparison to super-Earth structure models reveals the planet is likely an iron dominated world. The GJ 357 system adds to the small sample of low-mass planetary systems with well constrained masses, and further observational and dynamical follow-up is warranted to better understand the overall population of small multi-planet systems in the solar neighbourhood.

show abstract

Section: Introductionmentioning

confidence: 99%

GJ 357: a low-mass planetary system uncovered by precision radial velocities and dynamical simulations

Jenkins

Pozuelos

Tuomi

et al. 2019

Monthly Notices of the Royal Astronomical Society

View full text Add to dashboard Cite

show abstract

“…We found the host star is likely metal-rich, with a value for the iron abundance [Fe/H] of +0.11±0.09 dex. It is well established that gas giant planets favour metalrich stars (Gonzalez 1997;Santos et al 2002;Fischer & Valenti 2005;Wang & Fischer 2015), and also short period gas giants, including the HJ population, also appear even more metal-enhanced when compared to their longer period cousins (Jenkins et al 2017;Maldonado et al 2018). This trend appears to continue into the USP planet population also (Winn et al 2017).…”

Section: Discussionmentioning

confidence: 89%

NGTS-6b: an ultrashort period hot-Jupiter orbiting an old K dwarf

Vines

Jenkins

Acton

et al. 2019

Monthly Notices of the Royal Astronomical Society

View full text Add to dashboard Cite

We report the discovery of a new ultra-short period hot Jupiter from the Next Generation Transit Survey. NGTS-6b orbits its star with a period of 21.17 h, and has a mass and radius of 1.330 +0.024 −0.028 M J and 1.271 +0.197 −0.188 R J respectively, returning a planetary bulk density of 0.711 +0.214 −0.136 g cm −3 . Conforming to the currently known small population of ultra-short period hot Jupiters, the planet appears to orbit a metal-rich star ([Fe/H]= +0.11 ± 0.09 dex). Photoevaporation models suggest the planet should have lost 5% of its gaseous atmosphere over the course of the 9.6 Gyrs of evolution of the system. NGTS-6b adds to the small, but growing list of ultra-short period gas giant planets, and will help us to understand the dominant formation and evolutionary mechanisms that govern this population.

show abstract

“…Most of the multiple systems detected by RV surveys have 2-3 planets ), but as more data are obtained and found analysis tools refined undoubtedly more will be detected. For example, Jenkins et al (2014) a six planet in GL 587 to complement the other known planets (Delfosse et al 1998;Marcy et al 2001;Rivera et al 2005Correia et al 2010). …”

Section: Low Mass Planets and Compact Systemsmentioning

confidence: 99%

The Architecture of Exoplanets

Hatzes

2016

Space Sci Rev

View full text Add to dashboard Cite

Prior to the discovery of exoplanets our expectations of their architecture were largely driven by the properties of our solar system. We expected giant planets to lie in the outer regions and rocky planets in the inner regions. Planets should probably only occupy orbital distances 0.3-30 AU from the star. Planetary orbits should be circular, prograde and in the same plane. The reality of exoplanets have shattered these expectations. Jupiter-mass, Neptune-mass, Superearths, and even Earth-mass planets can orbit within 0.05 AU of the stars, sometimes with orbital periods of less than one day. Exoplanetary orbits can be eccentric, misaligned, and even in retrograde orbits. Radial velocity surveys gave the first hints that the occurrence rate increases with decreasing mass. This was put on a firm statistical basis with the Kepler mission that clearly demonstrated that there were more Neptuneand Superearth-sized planets than Jupiter-sized planets. These are often in multiple, densely packed systems where the planets all orbit within 0.3 AU of the star, a result also suggested by radial velocity surveys. Exoplanets also exhibit diversity along the main sequence. Massive stars tend to have a higher frequency of planets (≈ 20-25 %) that tend to be more massive (M ≈ 5-10 M Jup ). Giant planets around low mass stars are rare, but these stars show an abundance of small (Neptune and Superearth) planets in multiple systems. Planet formation is also not restricted to single stars as the Kepler mission has discovered several circumbinary planets. Although we have learned much about the architecture of planets over the past 20 years, we know little about the census of small planets at relatively large (a > 1 AU) orbital distances. We have yet to find a planetary system that is analogous to our own solar system. The question of how unique are the properties of our own solar system remains unanswered. Advancements in the detection methods of small planets over a wide range of orbital distances is needed before we gain a complete understanding of the architecture of exoplanetary systems.

show abstract

New planetary systems from the Calan–Hertfordshire Extrasolar Planet Search

Cited by 73 publications

References 88 publications

GJ 357: a low-mass planetary system uncovered by precision radial velocities and dynamical simulations

GJ 357: a low-mass planetary system uncovered by precision radial velocities and dynamical simulations

NGTS-6b: an ultrashort period hot-Jupiter orbiting an old K dwarf

The Architecture of Exoplanets

Contact Info

Product

Resources

About