Persson, C. M., Fridlund, M., Barragan, O., Dai, F., Gandolfi, D., Hatzes, A. P., Hirano, T., Grziwa, S., Korth, J., Prieto-Arranz, J., Fossati, L., Van Eylen, V., Justesen, A. B., Livingston, J., Kubyshkina, D., Deeg, H. J., Guenther, E. W., Nowak, G., Cabrera, J., Eigmueller, Ph, Csizmadia, Sz, Smith, A. M. S., Erikson, A., Albrecht, S., Alonso Sobrino, R., Cochran, W. D., Endl, M., Esposito, M., Fukui, A., Heeren, P., Hidalgo, D., Hjorth, M., Kuzuhara, M., Narita, N., Nespral, D., Palle, E., Paetzold, M., Rauer, H., Rodler, F. and Winn, J. N. (2018). Super-Earth of 8 M-circle plus in a 2.2-day orbit around the K5V star K2-216. Astron. Astrophys., 618. LES ULIS CEDEX A: EDP SCIENCES S A. ISSN 1432-0746

Full text not available from this repository.

Abstract

Context. Although thousands of exoplanets have been discovered to date, far fewer have been fully characterised, in particular super-Earths. The KESPRINT consortium identified K2-216 as a planetary candidate host star in the K2 space mission Campaign 8 field with a transiting super-Earth. The planet has recently been validated as well. Aims. Our aim was to confirm the detection and derive the main physical characteristics of K2-216b, including the mass. Methods. We performed a series of follow-up observations: high-resolution imaging with the FastCam camera at the TCS and the Infrared Camera and Spectrograph at Subaru, and high-resolution spectroscopy with HARPS (La Silla), HARPS-N (TNG), and FIES (NOT). The stellar spectra were analyzed with the SpecMatch-Emp and SME codes to derive the fundamental stellar properties. We analyzed the K2 light curve with the pyanet i software. The radial velocity measurements were modelled with both a Gaussian process (GP) regression and the so-called floating chunk offset (FCO) technique to simultaneously model the planetary signal and correlated noise associated with stellar activity. Results. Imaging confirms that K2-216 is a single star. Our analysis discloses that the star is a moderately active K5V star of mass 0.70 +/- 0.03 M-circle dot and radius 0.72 +/- 0.03 R-circle dot. Planet b is found to have a radius of 1.75(-0.10)(+0.17) R-circle plus and a 2.17-day orbit in agreement with previous results. We find consistent results for the planet mass from both models: M-p approximate to 7.4 +/- 2.2 M-circle plus from the GP regression and M-p approximate to 8.0 +/- 1.6 M-circle plus from the FCO technique, which implies that this planet is a super-Earth. The incident stellar flux is 248(-48)(+220) F-circle plus. Conclusions. The planet parameters put planet b in the middle of, or just below, the gap of the radius distribution of small planets. The density is consistent with a rocky composition of primarily iron and magnesium silicate. In agreement with theoretical predictions, we find that the planet is a remnant core, stripped of its atmosphere, and is one of the largest planets found that has lost its atmosphere.

Item Type: Journal Article
Creators:
CreatorsEmailORCIDORCID Put Code
Persson, C. M.UNSPECIFIEDUNSPECIFIEDUNSPECIFIED
Fridlund, M.UNSPECIFIEDUNSPECIFIEDUNSPECIFIED
Barragan, O.UNSPECIFIEDUNSPECIFIEDUNSPECIFIED
Dai, F.UNSPECIFIEDUNSPECIFIEDUNSPECIFIED
Gandolfi, D.UNSPECIFIEDUNSPECIFIEDUNSPECIFIED
Hatzes, A. P.UNSPECIFIEDUNSPECIFIEDUNSPECIFIED
Hirano, T.UNSPECIFIEDUNSPECIFIEDUNSPECIFIED
Grziwa, S.UNSPECIFIEDUNSPECIFIEDUNSPECIFIED
Korth, J.UNSPECIFIEDUNSPECIFIEDUNSPECIFIED
Prieto-Arranz, J.UNSPECIFIEDUNSPECIFIEDUNSPECIFIED
Fossati, L.UNSPECIFIEDUNSPECIFIEDUNSPECIFIED
Van Eylen, V.UNSPECIFIEDUNSPECIFIEDUNSPECIFIED
Justesen, A. B.UNSPECIFIEDUNSPECIFIEDUNSPECIFIED
Livingston, J.UNSPECIFIEDUNSPECIFIEDUNSPECIFIED
Kubyshkina, D.UNSPECIFIEDUNSPECIFIEDUNSPECIFIED
Deeg, H. J.UNSPECIFIEDUNSPECIFIEDUNSPECIFIED
Guenther, E. W.UNSPECIFIEDUNSPECIFIEDUNSPECIFIED
Nowak, G.UNSPECIFIEDUNSPECIFIEDUNSPECIFIED
Cabrera, J.UNSPECIFIEDUNSPECIFIEDUNSPECIFIED
Eigmueller, PhUNSPECIFIEDUNSPECIFIEDUNSPECIFIED
Csizmadia, SzUNSPECIFIEDUNSPECIFIEDUNSPECIFIED
Smith, A. M. S.UNSPECIFIEDUNSPECIFIEDUNSPECIFIED
Erikson, A.UNSPECIFIEDUNSPECIFIEDUNSPECIFIED
Albrecht, S.UNSPECIFIEDUNSPECIFIEDUNSPECIFIED
Alonso Sobrino, R.UNSPECIFIEDUNSPECIFIEDUNSPECIFIED
Cochran, W. D.UNSPECIFIEDUNSPECIFIEDUNSPECIFIED
Endl, M.UNSPECIFIEDUNSPECIFIEDUNSPECIFIED
Esposito, M.UNSPECIFIEDUNSPECIFIEDUNSPECIFIED
Fukui, A.UNSPECIFIEDUNSPECIFIEDUNSPECIFIED
Heeren, P.UNSPECIFIEDUNSPECIFIEDUNSPECIFIED
Hidalgo, D.UNSPECIFIEDUNSPECIFIEDUNSPECIFIED
Hjorth, M.UNSPECIFIEDUNSPECIFIEDUNSPECIFIED
Kuzuhara, M.UNSPECIFIEDUNSPECIFIEDUNSPECIFIED
Narita, N.UNSPECIFIEDUNSPECIFIEDUNSPECIFIED
Nespral, D.UNSPECIFIEDUNSPECIFIEDUNSPECIFIED
Palle, E.UNSPECIFIEDUNSPECIFIEDUNSPECIFIED
Paetzold, M.UNSPECIFIEDUNSPECIFIEDUNSPECIFIED
Rauer, H.UNSPECIFIEDUNSPECIFIEDUNSPECIFIED
Rodler, F.UNSPECIFIEDUNSPECIFIEDUNSPECIFIED
Winn, J. N.UNSPECIFIEDUNSPECIFIEDUNSPECIFIED
URN: urn:nbn:de:hbz:38-169442
DOI: 10.1051/0004-6361/201832867
Journal or Publication Title: Astron. Astrophys.
Volume: 618
Date: 2018
Publisher: EDP SCIENCES S A
Place of Publication: LES ULIS CEDEX A
ISSN: 1432-0746
Language: English
Faculty: Unspecified
Divisions: Unspecified
Subjects: no entry
Uncontrolled Keywords:
KeywordsLanguage
TRANSITING EXTRASOLAR PLANETS; COOL DWARF STARS; LOW-MASS STARS; BALMER LINES; STELLAR; SPECTROGRAPH; COMPANIONS; PARAMETERS; SEARCHMultiple languages
Astronomy & AstrophysicsMultiple languages
Refereed: Yes
URI: http://kups.ub.uni-koeln.de/id/eprint/16944

Downloads

Downloads per month over past year

Altmetric

Export

Actions (login required)

View Item View Item