THE K2-ESPRINT PROJECT III: A CLOSE-IN SUPER-EARTH AROUND A METAL-RICH MID-M DWARF
We validate a R[subscript p]=2.32 ± 0.24R[subscript ⊕] planet on a close-in orbit (P = 2.260455 ± 0.000041 days) around K2-28 (EPIC 206318379), a metal-rich M4-type dwarf in the Campaign 3 field of the K2 mission. Our follow-up observations included multi-band transit observations from the optical t...
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| Format: | Article |
| Language: | en_US |
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IOP Publishing
2017
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| Online Access: | http://hdl.handle.net/1721.1/108449 https://orcid.org/0000-0002-8958-0683 https://orcid.org/0000-0003-1667-5427 |
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| author | Hirano, Teruyuki Fukui, Akihiko Mann, Andrew W. Sanchis-Ojeda, Roberto Gaidos, Eric Narita, Norio Eylen, Vincent Van Lee, Chien-Hsiu Onozato, Hiroki Ryu, Tsuguru Kusakabe, Nobuhiko Ito, Ayaka Kuzuhara, Masayuki Onitsuka, Masahiro Tatsuuma, Misako Nowak, Grzegorz Pallè, Enric Ribas, Ignasi Tamura, Motohide Dai, Fei Yu, Liang |
| author2 | Massachusetts Institute of Technology. Department of Physics |
| author_facet | Massachusetts Institute of Technology. Department of Physics Hirano, Teruyuki Fukui, Akihiko Mann, Andrew W. Sanchis-Ojeda, Roberto Gaidos, Eric Narita, Norio Eylen, Vincent Van Lee, Chien-Hsiu Onozato, Hiroki Ryu, Tsuguru Kusakabe, Nobuhiko Ito, Ayaka Kuzuhara, Masayuki Onitsuka, Masahiro Tatsuuma, Misako Nowak, Grzegorz Pallè, Enric Ribas, Ignasi Tamura, Motohide Dai, Fei Yu, Liang |
| author_sort | Hirano, Teruyuki |
| collection | MIT |
| description | We validate a R[subscript p]=2.32 ± 0.24R[subscript ⊕] planet on a close-in orbit (P = 2.260455 ± 0.000041 days) around K2-28 (EPIC 206318379), a metal-rich M4-type dwarf in the Campaign 3 field of the K2 mission. Our follow-up observations included multi-band transit observations from the optical to the near-infrared, low-resolution spectroscopy, and high-resolution adaptive optics (AO) imaging. We perform a global fit to all of the observed transits using a Gaussian process-based method and show that the transit depths in all of the passbands adopted for the ground-based transit follow-ups (r₂′,z [subscript s,]₂,J,H,K[subscript s]) are within ~2σ of the K2 value. Based on a model of the background stellar population and the absence of nearby sources in our AO imaging, we estimate the probability that a background eclipsing binary could cause a false positive to be <2 × 10⁻⁵. We also show that K2-28 cannot have a physically associated companion of stellar type later than M4, based on the measurement of almost identical transit depths in multiple passbands. There is a low probability for an M4 dwarf companion (≈0.072 [subscript -0.04] [superscript +0.02]), but even if this were the case, the size of K2-28b falls within the planetary regime. K2-28b has the same radius (within 1σ) and experiences irradiation from its host star similar to the well-studied GJ 1214b. Given the relative brightness of K2-28 in the near-infrared (m[subscript Kep]= 14.85 mag and mH = 11.03 mag) and relatively deep transit (0.6%–0.7%), a comparison between the atmospheric properties of these two planets with future observations would be especially interesting. |
| first_indexed | 2024-09-23T11:07:30Z |
| format | Article |
| id | mit-1721.1/108449 |
| institution | Massachusetts Institute of Technology |
| language | en_US |
| last_indexed | 2024-09-23T11:07:30Z |
| publishDate | 2017 |
| publisher | IOP Publishing |
| record_format | dspace |
| spelling | mit-1721.1/1084492022-09-27T17:19:39Z THE K2-ESPRINT PROJECT III: A CLOSE-IN SUPER-EARTH AROUND A METAL-RICH MID-M DWARF Hirano, Teruyuki Fukui, Akihiko Mann, Andrew W. Sanchis-Ojeda, Roberto Gaidos, Eric Narita, Norio Eylen, Vincent Van Lee, Chien-Hsiu Onozato, Hiroki Ryu, Tsuguru Kusakabe, Nobuhiko Ito, Ayaka Kuzuhara, Masayuki Onitsuka, Masahiro Tatsuuma, Misako Nowak, Grzegorz Pallè, Enric Ribas, Ignasi Tamura, Motohide Dai, Fei Yu, Liang Massachusetts Institute of Technology. Department of Physics MIT Kavli Institute for Astrophysics and Space Research Dai, Fei Yu, Liang We validate a R[subscript p]=2.32 ± 0.24R[subscript ⊕] planet on a close-in orbit (P = 2.260455 ± 0.000041 days) around K2-28 (EPIC 206318379), a metal-rich M4-type dwarf in the Campaign 3 field of the K2 mission. Our follow-up observations included multi-band transit observations from the optical to the near-infrared, low-resolution spectroscopy, and high-resolution adaptive optics (AO) imaging. We perform a global fit to all of the observed transits using a Gaussian process-based method and show that the transit depths in all of the passbands adopted for the ground-based transit follow-ups (r₂′,z [subscript s,]₂,J,H,K[subscript s]) are within ~2σ of the K2 value. Based on a model of the background stellar population and the absence of nearby sources in our AO imaging, we estimate the probability that a background eclipsing binary could cause a false positive to be <2 × 10⁻⁵. We also show that K2-28 cannot have a physically associated companion of stellar type later than M4, based on the measurement of almost identical transit depths in multiple passbands. There is a low probability for an M4 dwarf companion (≈0.072 [subscript -0.04] [superscript +0.02]), but even if this were the case, the size of K2-28b falls within the planetary regime. K2-28b has the same radius (within 1σ) and experiences irradiation from its host star similar to the well-studied GJ 1214b. Given the relative brightness of K2-28 in the near-infrared (m[subscript Kep]= 14.85 mag and mH = 11.03 mag) and relatively deep transit (0.6%–0.7%), a comparison between the atmospheric properties of these two planets with future observations would be especially interesting. 2017-04-27T15:01:35Z 2017-04-27T15:01:35Z 2016-03 2015-11 Article http://purl.org/eprint/type/JournalArticle 1538-4357 0004-637X http://hdl.handle.net/1721.1/108449 Hirano, Teruyuki; Fukui, Akihiko; Mann, Andrew W.; Sanchis-Ojeda, Roberto; Gaidos, Eric; Narita, Norio; Dai, Fei, et al. “THE K2 -ESPRINT PROJECT III: A CLOSE-IN SUPER-EARTH AROUND A METAL-RICH MID-M DWARF.” The Astrophysical Journal 820, no. 1 (March 17, 2016): 41. © 2016. The American Astronomical Society https://orcid.org/0000-0002-8958-0683 https://orcid.org/0000-0003-1667-5427 en_US http://dx.doi.org/10.3847/0004-637x/820/1/41 Astrophysical Journal Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use. application/pdf IOP Publishing IOP Publishing |
| spellingShingle | Hirano, Teruyuki Fukui, Akihiko Mann, Andrew W. Sanchis-Ojeda, Roberto Gaidos, Eric Narita, Norio Eylen, Vincent Van Lee, Chien-Hsiu Onozato, Hiroki Ryu, Tsuguru Kusakabe, Nobuhiko Ito, Ayaka Kuzuhara, Masayuki Onitsuka, Masahiro Tatsuuma, Misako Nowak, Grzegorz Pallè, Enric Ribas, Ignasi Tamura, Motohide Dai, Fei Yu, Liang THE K2-ESPRINT PROJECT III: A CLOSE-IN SUPER-EARTH AROUND A METAL-RICH MID-M DWARF |
| title | THE K2-ESPRINT PROJECT III: A CLOSE-IN SUPER-EARTH AROUND A METAL-RICH MID-M DWARF |
| title_full | THE K2-ESPRINT PROJECT III: A CLOSE-IN SUPER-EARTH AROUND A METAL-RICH MID-M DWARF |
| title_fullStr | THE K2-ESPRINT PROJECT III: A CLOSE-IN SUPER-EARTH AROUND A METAL-RICH MID-M DWARF |
| title_full_unstemmed | THE K2-ESPRINT PROJECT III: A CLOSE-IN SUPER-EARTH AROUND A METAL-RICH MID-M DWARF |
| title_short | THE K2-ESPRINT PROJECT III: A CLOSE-IN SUPER-EARTH AROUND A METAL-RICH MID-M DWARF |
| title_sort | k2 esprint project iii a close in super earth around a metal rich mid m dwarf |
| url | http://hdl.handle.net/1721.1/108449 https://orcid.org/0000-0002-8958-0683 https://orcid.org/0000-0003-1667-5427 |
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