Lifetime Against Sublimation and an Initial Mass Estimate for the Exoplanet α Centauri Bb

Martin Beech; Lowell Peltier

doi:doi:10.11648/j.ajaa.20150304.11

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Lifetime Against Sublimation and an Initial Mass Estimate for the Exoplanet α Centauri Bb

Martin Beech, Lowell Peltier

Published in American Journal of Astronomy and Astrophysics (Volume 3, Issue 4)

Received: 22 August 2015 Accepted: 6 September 2015 Published: 18 September 2015

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Abstract

A two-component, core-mantle, model is developed to estimate the lifetime against destruction via sublimation of close-orbit, terrestrial-mass exoplanets. We specifically focus on the nearest terrestrial exoplanet, α Centauri Bb, since the parent star α Cen B has a reasonably well determined age of 6 ± 1 Gyr. This latter knowledge specifically enables an estimate to be made of the amount of mantle material lost by α Cen Bb since the system formed. Our planet model allows for an iron-core and olivine mantle structure, and it also follows the luminosity evolution of α Cen B. Our results suggest that α Cen Bb had an initial mass of order 2 M_Earth, and that of order 0.2 M_Earth of mantle material has been lost through sublimation since the planet formed. We additionally consider the fate of any putative planets, moving on circular orbits, interior to α Cen Bb (which has an orbital radius of 0.04 au), and it is found that any Earth mass, or lesser objects, orbiting closer than 0.024 au to α Cen B have lifetimes against destruction by sublimation smaller than 5 billion years.

Published in	American Journal of Astronomy and Astrophysics (Volume 3, Issue 4)
DOI	10.11648/j.ajaa.20150304.11
Page(s)	70-76
Creative Commons	This is an Open Access article, distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution and reproduction in any medium or format, provided the original work is properly cited.
Copyright	Copyright © The Author(s), 2015. Published by Science Publishing Group

Keywords

Exoplanets, α Centauri AB Star System, α Centauri Bb, Sublimation Lifetime

References

[1]	Beech, M. Alpha Centauri: unveiling the secrets of our nearest stellar neighbor. Springer, New York, 2015.
[2]	Wiegert, P., and Holman, M. J. 1997. The stability of planets in the alpha Centauri system. Astron. J. 113, 1445.
[3]	Dumusque, X., et al. 2012. An Earth mass planet orbiting alpha Centauri B. Nature, 491, 207.
[4]	Brice-Olivier, D., et al. 2015. Hubble Space Telescope search for the transit of the Earth-mass exoplanet Alpha Centauri Bb. http://arxiv.org/abs/1503.07528v1.
[5]	Volk, K., and Gladman, B. 2015. Consolidating and crushing exoplanets: did it happen here? http//arxiv.org/abs/1502.065581v1.
[6]	Plavchan, P., Chen, Xi, and Pohl, G. 2015. What is the mass of  Cen Bb? Ap. J. 805, id.174.
[7]	Bazot, M., Bourguignon, S., and Christensen-Dalsgaard, J. 2008. Estimation of stellar parameters using Monte Carlo Markov-chains. Mem. Soc. Astron. Italiana. 79, 660.
[8]	Mamajek, E. E., and Hillenbrand, L. A. 2008. Improved age estimates for solar-type dwarfs using activity-rotation diagnostics. Ap. J. 687, 1264.
[9]	Jura, M. 2008. Pollution of single white dwarfs by accretion of many small asteroids. Ap. J. 135, 1785.
[10]	Zubovas, K., Nayakshin S., and Markoff, S. 2011. Sgr A* flares: tidal disruption of asteroids and planets? http://arxiv.org/abs/1110.6872v1.
[11]	Perez-Becker, D., and Chiang, E. 2013. Catastrophic evaporation of rocky planets. http://arxiv.org/abs/1302.2147v3.
[12]	Van Lieshout, R., Min, M., and Dominik, C. 2014. Dusty tails of evaporating exoplanets 1. Constraints on the dust composition. Astron. Astrophys. 572, id.A76.
[13]	Marcy, G. W., et al. 2014. Occurrence and core-envelope structure of 1-4xEarth-size planets around Sun-like stars. PNAS. 111, 12655.
[14]	Townsend, R. 2015. http://www.astro.wisc.edu/~ townsend/static.php?ref=ez-web.
[15]	Beech, M. 2011. The far distant future of Alpha Centauri. JBIS. 64, 387.
[16]	Endl, M., Kurster, M., Els, S., Hatzes, A. P., and Cochran, W. D. 2001. The planet search program at the ESO Coude Echelle spectrometer II. The alpha Centauri system: Limits for planetary companions. Astron. Astrophys. 374, 675.
[17]	Guedes, J. M. et al. 2008. Formation and detectability of terrestrial planets around  Centauri B. Ap. J. 679, 1582.
[18]	Thebauld, P., Marzari, F., and Scholl, H. 2009. Planet formation in the habitability zone of alpha Centauri B. MNRAS. 393, L21.
[19]	Quintana, E. V., Lissauer, J. J., Chambers, J. E., and Duncan, M. J. 2002. Terrestrial planet formation in the  Centauri system. Ap. J. 576, 982.
[20]	Ford, E. D. 2014. Architectures of planetary systems and implications for their formation. PNAS. 111, 12616.
[21]	Pu, B. and Wu, Y. 2015. Spacing of Kepler planets: sculpting by dynamical instability. http://arxiv.org/abs/1502.05449v1.
[22]	Lissauer, J. J., Dawson, R. I., and Tremaine, S. 2014. Advances in exoplanet science from Kepler. Nature, 513, 336.
[23]	Hatzes, A. P. 2013. The radial velocity detection of Earth mass planet in the presence of activity noise: the case of  Cen Bb. Ap. J. 770, id.133.
[24]	Bergmann, C., Endl, M., Hearnshaw, J., Wittenmyer, R., and Wright, D. 2015. Searching for Earth-mass planets around  Centauri: precise radial velocities from contaminated spectra. Int. J. Astrobiology. 14, 173.
[25]	Endl, M., and Kuster, M. 2008. Towards detection of terrestrial planets in the habitable zone of our closest neighbor: Proxima Centauri. Astron. Astrophys. 488, 1149.
[26]	Zeng, L., and Seager, S. 2008. A computational tool to interpret the bulk composition of solid exoplanets based on mass and radius measurements. Pub. Astron. Soc. Pacific. 120, 983.
[27]	Grasset, O., Schneider, J., and Sotin, C. 2009. A study of the accuracy of mass-radius relationships for silicate-rich and ice-rich planets up to 100 Earth masses. Ap. J. 693, 722.
[28]	Beech, M., and Peltier, L. 2015. Vulcanoid asteroids and Sun-grazing comets: past encounters and possible outcomes. American Journal of Astronomy and Astrophysics, 3(2), 26.
[29]	Lin, H., and Loeb, A. 2014. Finding rocky asteroids around white dwarfs by their periodic thermal emission. Ap. J. Lett. 793, id.L43.
[30]	Poteet, C. A. et al. 2011. A Spitzer infrared spectrograph detection of crystalline silicates in a protostellar envelope. Ap. J. Lett. 733, id.L32.

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APA Style

Martin Beech, Lowell Peltier. (2015). Lifetime Against Sublimation and an Initial Mass Estimate for the Exoplanet α Centauri Bb. American Journal of Astronomy and Astrophysics, 3(4), 70-76. https://doi.org/10.11648/j.ajaa.20150304.11

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ACS Style

Martin Beech; Lowell Peltier. Lifetime Against Sublimation and an Initial Mass Estimate for the Exoplanet α Centauri Bb. Am. J. Astron. Astrophys. 2015, 3(4), 70-76. doi: 10.11648/j.ajaa.20150304.11

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AMA Style

Martin Beech, Lowell Peltier. Lifetime Against Sublimation and an Initial Mass Estimate for the Exoplanet α Centauri Bb. Am J Astron Astrophys. 2015;3(4):70-76. doi: 10.11648/j.ajaa.20150304.11

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@article{10.11648/j.ajaa.20150304.11,
  author = {Martin Beech and Lowell Peltier},
  title = {Lifetime Against Sublimation and an Initial Mass Estimate for the Exoplanet α Centauri Bb},
  journal = {American Journal of Astronomy and Astrophysics},
  volume = {3},
  number = {4},
  pages = {70-76},
  doi = {10.11648/j.ajaa.20150304.11},
  url = {https://doi.org/10.11648/j.ajaa.20150304.11},
  eprint = {https://article.sciencepublishinggroup.com/pdf/10.11648.j.ajaa.20150304.11},
  abstract = {A two-component, core-mantle, model is developed to estimate the lifetime against destruction via sublimation of close-orbit, terrestrial-mass exoplanets. We specifically focus on the nearest terrestrial exoplanet, α Centauri Bb, since the parent star α Cen B has a reasonably well determined age of 6 ± 1 Gyr. This latter knowledge specifically enables an estimate to be made of the amount of mantle material lost by α Cen Bb since the system formed. Our planet model allows for an iron-core and olivine mantle structure, and it also follows the luminosity evolution of α Cen B. Our results suggest that α Cen Bb had an initial mass of order 2 MEarth, and that of order 0.2 MEarth of mantle material has been lost through sublimation since the planet formed. We additionally consider the fate of any putative planets, moving on circular orbits, interior to α Cen Bb (which has an orbital radius of 0.04 au), and it is found that any Earth mass, or lesser objects, orbiting closer than 0.024 au to α Cen B have lifetimes against destruction by sublimation smaller than 5 billion years.},
 year = {2015}
}

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TY  - JOUR
T1  - Lifetime Against Sublimation and an Initial Mass Estimate for the Exoplanet α Centauri Bb
AU  - Martin Beech
AU  - Lowell Peltier
Y1  - 2015/09/18
PY  - 2015
N1  - https://doi.org/10.11648/j.ajaa.20150304.11
DO  - 10.11648/j.ajaa.20150304.11
T2  - American Journal of Astronomy and Astrophysics
JF  - American Journal of Astronomy and Astrophysics
JO  - American Journal of Astronomy and Astrophysics
SP  - 70
EP  - 76
PB  - Science Publishing Group
SN  - 2376-4686
UR  - https://doi.org/10.11648/j.ajaa.20150304.11
AB  - A two-component, core-mantle, model is developed to estimate the lifetime against destruction via sublimation of close-orbit, terrestrial-mass exoplanets. We specifically focus on the nearest terrestrial exoplanet, α Centauri Bb, since the parent star α Cen B has a reasonably well determined age of 6 ± 1 Gyr. This latter knowledge specifically enables an estimate to be made of the amount of mantle material lost by α Cen Bb since the system formed. Our planet model allows for an iron-core and olivine mantle structure, and it also follows the luminosity evolution of α Cen B. Our results suggest that α Cen Bb had an initial mass of order 2 MEarth, and that of order 0.2 MEarth of mantle material has been lost through sublimation since the planet formed. We additionally consider the fate of any putative planets, moving on circular orbits, interior to α Cen Bb (which has an orbital radius of 0.04 au), and it is found that any Earth mass, or lesser objects, orbiting closer than 0.024 au to α Cen B have lifetimes against destruction by sublimation smaller than 5 billion years.
VL  - 3
IS  - 4
ER  -

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Author Information

Martin Beech

Campion College, the University of Regina, Regina, SK., Canada
Lowell Peltier

Department of Physics, the University of Regina, Regina, SK., Canada

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APA Style

Martin Beech, Lowell Peltier. (2015). Lifetime Against Sublimation and an Initial Mass Estimate for the Exoplanet α Centauri Bb. American Journal of Astronomy and Astrophysics, 3(4), 70-76. https://doi.org/10.11648/j.ajaa.20150304.11

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ACS Style

Martin Beech; Lowell Peltier. Lifetime Against Sublimation and an Initial Mass Estimate for the Exoplanet α Centauri Bb. Am. J. Astron. Astrophys. 2015, 3(4), 70-76. doi: 10.11648/j.ajaa.20150304.11

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AMA Style

Martin Beech, Lowell Peltier. Lifetime Against Sublimation and an Initial Mass Estimate for the Exoplanet α Centauri Bb. Am J Astron Astrophys. 2015;3(4):70-76. doi: 10.11648/j.ajaa.20150304.11

Copy | Download

@article{10.11648/j.ajaa.20150304.11,
  author = {Martin Beech and Lowell Peltier},
  title = {Lifetime Against Sublimation and an Initial Mass Estimate for the Exoplanet α Centauri Bb},
  journal = {American Journal of Astronomy and Astrophysics},
  volume = {3},
  number = {4},
  pages = {70-76},
  doi = {10.11648/j.ajaa.20150304.11},
  url = {https://doi.org/10.11648/j.ajaa.20150304.11},
  eprint = {https://article.sciencepublishinggroup.com/pdf/10.11648.j.ajaa.20150304.11},
  abstract = {A two-component, core-mantle, model is developed to estimate the lifetime against destruction via sublimation of close-orbit, terrestrial-mass exoplanets. We specifically focus on the nearest terrestrial exoplanet, α Centauri Bb, since the parent star α Cen B has a reasonably well determined age of 6 ± 1 Gyr. This latter knowledge specifically enables an estimate to be made of the amount of mantle material lost by α Cen Bb since the system formed. Our planet model allows for an iron-core and olivine mantle structure, and it also follows the luminosity evolution of α Cen B. Our results suggest that α Cen Bb had an initial mass of order 2 MEarth, and that of order 0.2 MEarth of mantle material has been lost through sublimation since the planet formed. We additionally consider the fate of any putative planets, moving on circular orbits, interior to α Cen Bb (which has an orbital radius of 0.04 au), and it is found that any Earth mass, or lesser objects, orbiting closer than 0.024 au to α Cen B have lifetimes against destruction by sublimation smaller than 5 billion years.},
 year = {2015}
}

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TY  - JOUR
T1  - Lifetime Against Sublimation and an Initial Mass Estimate for the Exoplanet α Centauri Bb
AU  - Martin Beech
AU  - Lowell Peltier
Y1  - 2015/09/18
PY  - 2015
N1  - https://doi.org/10.11648/j.ajaa.20150304.11
DO  - 10.11648/j.ajaa.20150304.11
T2  - American Journal of Astronomy and Astrophysics
JF  - American Journal of Astronomy and Astrophysics
JO  - American Journal of Astronomy and Astrophysics
SP  - 70
EP  - 76
PB  - Science Publishing Group
SN  - 2376-4686
UR  - https://doi.org/10.11648/j.ajaa.20150304.11
AB  - A two-component, core-mantle, model is developed to estimate the lifetime against destruction via sublimation of close-orbit, terrestrial-mass exoplanets. We specifically focus on the nearest terrestrial exoplanet, α Centauri Bb, since the parent star α Cen B has a reasonably well determined age of 6 ± 1 Gyr. This latter knowledge specifically enables an estimate to be made of the amount of mantle material lost by α Cen Bb since the system formed. Our planet model allows for an iron-core and olivine mantle structure, and it also follows the luminosity evolution of α Cen B. Our results suggest that α Cen Bb had an initial mass of order 2 MEarth, and that of order 0.2 MEarth of mantle material has been lost through sublimation since the planet formed. We additionally consider the fate of any putative planets, moving on circular orbits, interior to α Cen Bb (which has an orbital radius of 0.04 au), and it is found that any Earth mass, or lesser objects, orbiting closer than 0.024 au to α Cen B have lifetimes against destruction by sublimation smaller than 5 billion years.
VL  - 3
IS  - 4
ER  -

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