We report the independent discovery and characterization of two K2 planets: K2-180b, a mini-Neptune-sized planet in an 8.9-d orbit transiting a V = 12.6 mag, metal-poor ([Fe/H] = -0.65 ± 0.10) K2V star in K2 campaign 5; K2-140b, a transiting hot Jupiter in a 6.6-d orbit around a V = 12.6 mag G6V ([Fe/H] = + 0.10 ± 0.10) star in K2 campaign 10. Our results are based on K2 time-series photometry combined with high-spatial resolution imaging and high-precision radial velocity measurements. We present the first mass measurement of K2-180b. K2-180b has a mass of Mp = 11.3 ± 1.9 M_Earth and a radius of Rp = 2.2 ± 0.1 R_Earth, yielding a mean density of ρp = 5.6 ± 1.9 g cm-3, suggesting a rocky composition. Given its radius, K2-180b is above the region of the so-called `planetary radius gap'. K2-180b is in addition not only one of the densest mini-Neptune-sized planets, but also one of the few mini-Neptune-sized planets known to transit a metal-poor star. We also constrain the planetary and orbital parameters of K2-140b and show that, given the currently available Doppler measurements, the eccentricity is consistent with zero, contrary to the results of a previous study.

K2-140b and K2-180b - Characterization of a hot Jupiter and a mini-Neptune from the K2 mission

Gandolfi D.;Barragan O.;
2019-01-01

Abstract

We report the independent discovery and characterization of two K2 planets: K2-180b, a mini-Neptune-sized planet in an 8.9-d orbit transiting a V = 12.6 mag, metal-poor ([Fe/H] = -0.65 ± 0.10) K2V star in K2 campaign 5; K2-140b, a transiting hot Jupiter in a 6.6-d orbit around a V = 12.6 mag G6V ([Fe/H] = + 0.10 ± 0.10) star in K2 campaign 10. Our results are based on K2 time-series photometry combined with high-spatial resolution imaging and high-precision radial velocity measurements. We present the first mass measurement of K2-180b. K2-180b has a mass of Mp = 11.3 ± 1.9 M_Earth and a radius of Rp = 2.2 ± 0.1 R_Earth, yielding a mean density of ρp = 5.6 ± 1.9 g cm-3, suggesting a rocky composition. Given its radius, K2-180b is above the region of the so-called `planetary radius gap'. K2-180b is in addition not only one of the densest mini-Neptune-sized planets, but also one of the few mini-Neptune-sized planets known to transit a metal-poor star. We also constrain the planetary and orbital parameters of K2-140b and show that, given the currently available Doppler measurements, the eccentricity is consistent with zero, contrary to the results of a previous study.
2019
482
2
1807
1823
https://ui.adsabs.harvard.edu/link_gateway/2019MNRAS.482.1807K/PUB_HTML
Planets and satellites: fundamental parameters; Stars: fundamental parameters; Stars: individual: K2-140; Stars: individual: K2-180; Techniques: photometric; Techniques: radial velocities
Korth J.; Csizmadia S.; Gandolfi D.; Fridlund M.; Patzold M.; Hirano T.; Livingston J.; Persson C.M.; Deeg H.J.; Justesen A.B.; Barragan O.; Grziwa S.; Endl M.; Tronsgaard R.; Dai F.; Cochran W.D.; Albrecht S.; Alonso R.; Cabrera J.; Cauley P.W.; Cusano F.; Eigmuller P.; Erikson A.; Esposito M.; Guenther E.W.; Hatzes A.P.; Hidalgo D.; Kuzuhara M.; Montanes P.; Napolitano N.R.; Narita N.; Niraula P.; Nespral D.; Nowak G.; Palle E.; Petrillo C.E.; Redfield S.; Prieto-Arranz J.; Rauer H.; Smith A.; Tortora C.; Van Eylen V.; Winn J.N.
File in questo prodotto:
File Dimensione Formato  
Korth_2019.pdf

Accesso aperto

Tipo di file: POSTPRINT (VERSIONE FINALE DELL’AUTORE)
Dimensione 3.59 MB
Formato Adobe PDF
3.59 MB Adobe PDF Visualizza/Apri

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/2318/1711542
Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 16
  • ???jsp.display-item.citation.isi??? 16
social impact