University of Hertfordshire

The CARMENES search for exoplanets around M dwarfs. Characterization of the nearby ultra-compact multiplanetary system YZ Ceti

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The CARMENES search for exoplanets around M dwarfs. Characterization of the nearby ultra-compact multiplanetary system YZ Ceti. / Stock, S.; Kemmer, J.; Reffert, S.; Trifonov, T.; Kaminski, A.; Dreizler, S.; Quirrenbach, A.; Caballero, J. A.; Reiners, A.; Jeffers, S. V.; Anglada-Escudé, G.; Ribas, I.; Amado, P. J.; Barrado, D.; Barnes, J. R.; Bauer, F. F.; Berdiñas, Z. M.; Béjar, V. J. S.; Coleman, G. A. L.; Cortés-Contreras, M.; Díez-Alonso, E.; Domínguez-Fernández, A. J.; Espinoza, N.; Haswell, C. A.; Hatzes, A.; Henning, T.; Jenkins, J. S.; Jones, H. R. A.; Kossakowski, D.; Kürster, M.; Lafarga, M.; Lee, M. H.; González, M. J. López; Montes, D.; Morales, J. C.; Morales, N.; Pallé, E.; Pedraz, S.; guez, E. Rodrí; Rodríguez-López, C.; Zechmeister, M.

In: Astronomy & Astrophysics, Vol. 636, A119, 07.02.2020.

Research output: Contribution to journalArticlepeer-review

Harvard

Stock, S, Kemmer, J, Reffert, S, Trifonov, T, Kaminski, A, Dreizler, S, Quirrenbach, A, Caballero, JA, Reiners, A, Jeffers, SV, Anglada-Escudé, G, Ribas, I, Amado, PJ, Barrado, D, Barnes, JR, Bauer, FF, Berdiñas, ZM, Béjar, VJS, Coleman, GAL, Cortés-Contreras, M, Díez-Alonso, E, Domínguez-Fernández, AJ, Espinoza, N, Haswell, CA, Hatzes, A, Henning, T, Jenkins, JS, Jones, HRA, Kossakowski, D, Kürster, M, Lafarga, M, Lee, MH, González, MJL, Montes, D, Morales, JC, Morales, N, Pallé, E, Pedraz, S, guez, ER, Rodríguez-López, C & Zechmeister, M 2020, 'The CARMENES search for exoplanets around M dwarfs. Characterization of the nearby ultra-compact multiplanetary system YZ Ceti', Astronomy & Astrophysics, vol. 636, A119. https://doi.org/10.1051/0004-6361/201936732

APA

Stock, S., Kemmer, J., Reffert, S., Trifonov, T., Kaminski, A., Dreizler, S., Quirrenbach, A., Caballero, J. A., Reiners, A., Jeffers, S. V., Anglada-Escudé, G., Ribas, I., Amado, P. J., Barrado, D., Barnes, J. R., Bauer, F. F., Berdiñas, Z. M., Béjar, V. J. S., Coleman, G. A. L., ... Zechmeister, M. (2020). The CARMENES search for exoplanets around M dwarfs. Characterization of the nearby ultra-compact multiplanetary system YZ Ceti. Astronomy & Astrophysics, 636, [A119]. https://doi.org/10.1051/0004-6361/201936732

Author

Stock, S. ; Kemmer, J. ; Reffert, S. ; Trifonov, T. ; Kaminski, A. ; Dreizler, S. ; Quirrenbach, A. ; Caballero, J. A. ; Reiners, A. ; Jeffers, S. V. ; Anglada-Escudé, G. ; Ribas, I. ; Amado, P. J. ; Barrado, D. ; Barnes, J. R. ; Bauer, F. F. ; Berdiñas, Z. M. ; Béjar, V. J. S. ; Coleman, G. A. L. ; Cortés-Contreras, M. ; Díez-Alonso, E. ; Domínguez-Fernández, A. J. ; Espinoza, N. ; Haswell, C. A. ; Hatzes, A. ; Henning, T. ; Jenkins, J. S. ; Jones, H. R. A. ; Kossakowski, D. ; Kürster, M. ; Lafarga, M. ; Lee, M. H. ; González, M. J. López ; Montes, D. ; Morales, J. C. ; Morales, N. ; Pallé, E. ; Pedraz, S. ; guez, E. Rodrí ; Rodríguez-López, C. ; Zechmeister, M. / The CARMENES search for exoplanets around M dwarfs. Characterization of the nearby ultra-compact multiplanetary system YZ Ceti. In: Astronomy & Astrophysics. 2020 ; Vol. 636.

Bibtex

@article{f50ebbbd96ee4243be149bf92b1a408d,
title = "The CARMENES search for exoplanets around M dwarfs. Characterization of the nearby ultra-compact multiplanetary system YZ Ceti",
abstract = "Context. The nearby ultra-compact multiplanetary system YZ Ceti consists of at least three planets, and a fourth tentative signal. The orbital period of each planet is the subject of discussion in the literature due to strong aliasing in the radial velocity data. The stellar activity of this M dwarf also hampers significantly the derivation of the planetary parameters. Aims. With an additional 229 radial velocity measurements obtained since the discovery publication, we reanalyze the YZ Ceti system and resolve the alias issues. Methods. We use model comparison in the framework of Bayesian statistics and periodogram simulations based on a method by Dawson and Fabrycky to resolve the aliases. We discuss additional signals in the RV data, and derive the planetary parameters by simultaneously modeling the stellar activity with a Gaussian process regression model. To constrain the planetary parameters further we apply a stability analysis on our ensemble of Keplerian fits. Results. We find no evidence for a fourth possible companion. We resolve the aliases: the three planets orbit the star with periods of 2.02 d, 3.06 d, and 4.66 d. We also investigate an effect of the stellar rotational signal on the derivation of the planetary parameters, in particular the eccentricity of the innermost planet. Using photometry we determine the stellar rotational period to be close to 68 d and we also detect this signal in the residuals of a three-planet fit to the RV data and the spectral activity indicators. From our stability analysis we derive a lower limit on the inclination of the system with the assumption of coplanar orbits which is imin = 0.9 deg. From the absence of a transit event with TESS, we derive an upper limit of the inclination of imax = 87.43 deg. Conclusions. YZ Ceti is a prime example of a system where strong aliasing hindered the determination of the orbital periods of exoplanets. Additionally, stellar activity influences the derivation of planetary parameters and modeling them correctly is important for the reliable estimation of the orbital parameters in this specific compact system. Stability considerations then allow additional constraints to be placed on the planetary parameters.",
keywords = "Planetary systems, Planets and satellites: dynamical evolution and stability, Planets and satellites: terrestrial planets, Stars: individual: YZ Ceti, Stars: late-type, Techniques: radial velocities",
author = "S. Stock and J. Kemmer and S. Reffert and T. Trifonov and A. Kaminski and S. Dreizler and A. Quirrenbach and Caballero, {J. A.} and A. Reiners and Jeffers, {S. V.} and G. Anglada-Escud{\'e} and I. Ribas and Amado, {P. J.} and D. Barrado and Barnes, {J. R.} and Bauer, {F. F.} and Berdi{\~n}as, {Z. M.} and B{\'e}jar, {V. J. S.} and Coleman, {G. A. L.} and M. Cort{\'e}s-Contreras and E. D{\'i}ez-Alonso and Dom{\'i}nguez-Fern{\'a}ndez, {A. J.} and N. Espinoza and Haswell, {C. A.} and A. Hatzes and T. Henning and Jenkins, {J. S.} and Jones, {H. R. A.} and D. Kossakowski and M. K{\"u}rster and M. Lafarga and Lee, {M. H.} and Gonz{\'a}lez, {M. J. L{\'o}pez} and D. Montes and Morales, {J. C.} and N. Morales and E. Pall{\'e} and S. Pedraz and guez, {E. Rodr{\'i}} and C. Rodr{\'i}guez-L{\'o}pez and M. Zechmeister",
year = "2020",
month = feb,
day = "7",
doi = "10.1051/0004-6361/201936732",
language = "English",
volume = "636",
journal = "Astronomy & Astrophysics",
issn = "0004-6361",
publisher = "EDP Sciences",

}

RIS

TY - JOUR

T1 - The CARMENES search for exoplanets around M dwarfs. Characterization of the nearby ultra-compact multiplanetary system YZ Ceti

AU - Stock, S.

AU - Kemmer, J.

AU - Reffert, S.

AU - Trifonov, T.

AU - Kaminski, A.

AU - Dreizler, S.

AU - Quirrenbach, A.

AU - Caballero, J. A.

AU - Reiners, A.

AU - Jeffers, S. V.

AU - Ribas, I.

AU - Barnes, J. R.

AU - Bauer, F. F.

AU - Berdiñas, Z. M.

AU - Béjar, V. J. S.

AU - Coleman, G. A. L.

AU - Cortés-Contreras, M.

AU - Díez-Alonso, E.

AU - Domínguez-Fernández, A. J.

AU - Espinoza, N.

AU - Haswell, C. A.

AU - Hatzes, A.

AU - Henning, T.

AU - Jenkins, J. S.

AU - Jones, H. R. A.

AU - Kossakowski, D.

AU - Kürster, M.

AU - Lafarga, M.

AU - Lee, M. H.

AU - González, M. J. López

AU - Montes, D.

AU - Morales, J. C.

AU - Morales, N.

AU - Pallé, E.

AU - Pedraz, S.

AU - guez, E. Rodrí

AU - Rodríguez-López, C.

AU - Zechmeister, M.

PY - 2020/2/7

Y1 - 2020/2/7

N2 - Context. The nearby ultra-compact multiplanetary system YZ Ceti consists of at least three planets, and a fourth tentative signal. The orbital period of each planet is the subject of discussion in the literature due to strong aliasing in the radial velocity data. The stellar activity of this M dwarf also hampers significantly the derivation of the planetary parameters. Aims. With an additional 229 radial velocity measurements obtained since the discovery publication, we reanalyze the YZ Ceti system and resolve the alias issues. Methods. We use model comparison in the framework of Bayesian statistics and periodogram simulations based on a method by Dawson and Fabrycky to resolve the aliases. We discuss additional signals in the RV data, and derive the planetary parameters by simultaneously modeling the stellar activity with a Gaussian process regression model. To constrain the planetary parameters further we apply a stability analysis on our ensemble of Keplerian fits. Results. We find no evidence for a fourth possible companion. We resolve the aliases: the three planets orbit the star with periods of 2.02 d, 3.06 d, and 4.66 d. We also investigate an effect of the stellar rotational signal on the derivation of the planetary parameters, in particular the eccentricity of the innermost planet. Using photometry we determine the stellar rotational period to be close to 68 d and we also detect this signal in the residuals of a three-planet fit to the RV data and the spectral activity indicators. From our stability analysis we derive a lower limit on the inclination of the system with the assumption of coplanar orbits which is imin = 0.9 deg. From the absence of a transit event with TESS, we derive an upper limit of the inclination of imax = 87.43 deg. Conclusions. YZ Ceti is a prime example of a system where strong aliasing hindered the determination of the orbital periods of exoplanets. Additionally, stellar activity influences the derivation of planetary parameters and modeling them correctly is important for the reliable estimation of the orbital parameters in this specific compact system. Stability considerations then allow additional constraints to be placed on the planetary parameters.

AB - Context. The nearby ultra-compact multiplanetary system YZ Ceti consists of at least three planets, and a fourth tentative signal. The orbital period of each planet is the subject of discussion in the literature due to strong aliasing in the radial velocity data. The stellar activity of this M dwarf also hampers significantly the derivation of the planetary parameters. Aims. With an additional 229 radial velocity measurements obtained since the discovery publication, we reanalyze the YZ Ceti system and resolve the alias issues. Methods. We use model comparison in the framework of Bayesian statistics and periodogram simulations based on a method by Dawson and Fabrycky to resolve the aliases. We discuss additional signals in the RV data, and derive the planetary parameters by simultaneously modeling the stellar activity with a Gaussian process regression model. To constrain the planetary parameters further we apply a stability analysis on our ensemble of Keplerian fits. Results. We find no evidence for a fourth possible companion. We resolve the aliases: the three planets orbit the star with periods of 2.02 d, 3.06 d, and 4.66 d. We also investigate an effect of the stellar rotational signal on the derivation of the planetary parameters, in particular the eccentricity of the innermost planet. Using photometry we determine the stellar rotational period to be close to 68 d and we also detect this signal in the residuals of a three-planet fit to the RV data and the spectral activity indicators. From our stability analysis we derive a lower limit on the inclination of the system with the assumption of coplanar orbits which is imin = 0.9 deg. From the absence of a transit event with TESS, we derive an upper limit of the inclination of imax = 87.43 deg. Conclusions. YZ Ceti is a prime example of a system where strong aliasing hindered the determination of the orbital periods of exoplanets. Additionally, stellar activity influences the derivation of planetary parameters and modeling them correctly is important for the reliable estimation of the orbital parameters in this specific compact system. Stability considerations then allow additional constraints to be placed on the planetary parameters.

KW - Planetary systems

KW - Planets and satellites: dynamical evolution and stability

KW - Planets and satellites: terrestrial planets

KW - Stars: individual: YZ Ceti

KW - Stars: late-type

UR - http://www.scopus.com/inward/record.url?scp=85088150119&partnerID=8YFLogxK

U2 - 10.1051/0004-6361/201936732

DO - 10.1051/0004-6361/201936732

M3 - Article

VL - 636

JO - Astronomy & Astrophysics

JF - Astronomy & Astrophysics

SN - 0004-6361

M1 - A119

ER -