K2-155 : A Bright Metal-poor M Dwarf with Three Transiting Super-Earths
(2018) In Astronomical Journal 155(3).- Abstract
We report on the discovery of three transiting super-Earths around K2-155 (EPIC 210897587), a relatively bright early M dwarf (V = 12.81 mag) observed during Campaign 13 of the NASA K2 mission. To characterize the system and validate the planet candidates, we conducted speckle imaging and high-dispersion optical spectroscopy, including radial velocity measurements. Based on the K2 light curve and the spectroscopic characterization of the host star, the planet sizes and orbital periods are 1.55-0.17+0.20R⊕ and 6.34365 ±0.00028 days for the inner planet; 1.95-0.22+0.27R⊕ and 13.85402 ±0.00088 days for the middle planet; and 1.64-0.17+0.18 R⊕... (More)
We report on the discovery of three transiting super-Earths around K2-155 (EPIC 210897587), a relatively bright early M dwarf (V = 12.81 mag) observed during Campaign 13 of the NASA K2 mission. To characterize the system and validate the planet candidates, we conducted speckle imaging and high-dispersion optical spectroscopy, including radial velocity measurements. Based on the K2 light curve and the spectroscopic characterization of the host star, the planet sizes and orbital periods are 1.55-0.17+0.20R⊕ and 6.34365 ±0.00028 days for the inner planet; 1.95-0.22+0.27R⊕ and 13.85402 ±0.00088 days for the middle planet; and 1.64-0.17+0.18 R⊕ and 40.6835 ±0.0031 days for the outer planet. The outer planet (K2-155d) is near the habitable zone, with an insolation 1.67 ±0.38 times that of the Earth. The planet's radius falls within the range between that of smaller rocky planets and larger gas-rich planets. To assess the habitability of this planet, we present a series of three-dimensional global climate simulations, assuming that K2-155d is tidally locked and has an Earth-like composition and atmosphere. We find that the planet can maintain a moderate surface temperature if the insolation proves to be smaller than ∼1.5 times that of the Earth. Doppler mass measurements, transit spectroscopy, and other follow-up observations should be rewarding, as K2-155 is one of the optically brightest M dwarfs known to harbor transiting planets.
(Less)
- author
- publishing date
- 2018-03
- type
- Contribution to journal
- publication status
- published
- keywords
- planets and satellites: detection, stars: individual (K2-155 = EPIC 210897587), techniques: photometric, techniques: radial velocities, techniques: spectroscopic
- in
- Astronomical Journal
- volume
- 155
- issue
- 3
- article number
- 124
- publisher
- IOP Publishing
- external identifiers
-
- scopus:85043605959
- ISSN
- 0004-6256
- DOI
- 10.3847/1538-3881/aaaa6e
- language
- English
- LU publication?
- no
- additional info
- Publisher Copyright: © 2018. The American Astronomical Society. All rights reserved.
- id
- f2087880-081e-4e1e-8f00-c7de5e119e43
- date added to LUP
- 2023-02-02 12:21:06
- date last changed
- 2023-02-21 10:34:21
@article{f2087880-081e-4e1e-8f00-c7de5e119e43,
abstract = {{<p>We report on the discovery of three transiting super-Earths around K2-155 (EPIC 210897587), a relatively bright early M dwarf (V = 12.81 mag) observed during Campaign 13 of the NASA K2 mission. To characterize the system and validate the planet candidates, we conducted speckle imaging and high-dispersion optical spectroscopy, including radial velocity measurements. Based on the K2 light curve and the spectroscopic characterization of the host star, the planet sizes and orbital periods are 1.55<sub>-0.17</sub><sup>+0.20</sup>R<sub>⊕</sub> and 6.34365 ±0.00028 days for the inner planet; 1.95<sub>-0.22</sub><sup>+0.27</sup>R<sub>⊕</sub> and 13.85402 ±0.00088 days for the middle planet; and 1.64<sub>-0.17</sub><sup>+0.18</sup> R<sub>⊕</sub> and 40.6835 ±0.0031 days for the outer planet. The outer planet (K2-155d) is near the habitable zone, with an insolation 1.67 ±0.38 times that of the Earth. The planet's radius falls within the range between that of smaller rocky planets and larger gas-rich planets. To assess the habitability of this planet, we present a series of three-dimensional global climate simulations, assuming that K2-155d is tidally locked and has an Earth-like composition and atmosphere. We find that the planet can maintain a moderate surface temperature if the insolation proves to be smaller than ∼1.5 times that of the Earth. Doppler mass measurements, transit spectroscopy, and other follow-up observations should be rewarding, as K2-155 is one of the optically brightest M dwarfs known to harbor transiting planets.</p>}},
author = {{Hirano, Teruyuki and Dai, Fei and Livingston, John H. and Fujii, Yuka and Cochran, William D. and Endl, Michael and Gandolfi, Davide and Redfield, Seth and Winn, Joshua N. and Guenther, Eike W. and Prieto-Arranz, Jorge and Albrecht, Simon and Barragan, Oscar and Cabrera, Juan and Cauley, P. Wilson and Csizmadia, Szilard and Deeg, Hans and Eigmüller, Philipp and Erikson, Anders and Fridlund, Malcolm and Fukui, Akihiko and Grziwa, Sascha and Hatzes, Artie P. and Korth, Judith and Narita, Norio and Nespral, David and Niraula, Prajwal and Nowak, Grzegorz and Pätzold, Martin and Palle, Enric and Persson, Carina M. and Rauer, Heike and Ribas, Ignasi and Smith, Alexis M.S. and Eylen, Vincent Van}},
issn = {{0004-6256}},
keywords = {{planets and satellites: detection; stars: individual (K2-155 = EPIC 210897587); techniques: photometric; techniques: radial velocities; techniques: spectroscopic}},
language = {{eng}},
number = {{3}},
publisher = {{IOP Publishing}},
series = {{Astronomical Journal}},
title = {{K2-155 : A Bright Metal-poor M Dwarf with Three Transiting Super-Earths}},
url = {{http://dx.doi.org/10.3847/1538-3881/aaaa6e}},
doi = {{10.3847/1538-3881/aaaa6e}},
volume = {{155}},
year = {{2018}},
}