Projects per year
Abstract
While brown dwarfs show similarities to stars early in their lives, their spin evolutions are much more akin to those of planets. We have used light curves from the K2 mission to measure new rotation periods for 18 young brown dwarfs in the Taurus star-forming region. Our sample spans masses from 0.02 to 0.08 M ⊙ and has been characterized extensively in the past. To search for periods, we utilize three different methods (autocorrelation, periodogram, Gaussian processes). The median period for brown dwarfs with disks is twice as long as for those without (3.1 versus 1.6 days), a signature of rotational braking by the disk, albeit with small numbers. With an overall median period of 1.9 days, brown dwarfs in Taurus rotate slower than their counterparts in somewhat older (3–10 Myr) star-forming regions, consistent with spin-up of the latter due to contraction and angular momentum conservation, a clear sign that disk braking overall is inefficient and/or temporary in this mass domain. We confirm the presence of a linear increase of the typical rotation period as a function of mass in the substellar regime. The rotational velocities, when calculated forward to the age of the solar system, assuming angular momentum conservation, fit the known spin–mass relation for solar system planets and extra-solar planetary-mass objects. This spin–mass trend holds over six orders of magnitude in mass, including objects from several different formation paths. Our result implies that brown dwarfs by and large retain their primordial angular momentum through the first few Myr of their evolution.
Original language | English |
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Article number | 153 |
Number of pages | 10 |
Journal | Astrophysical Journal |
Volume | 859 |
Issue number | 2 |
Early online date | 4 Jun 2018 |
DOIs | |
Publication status | Published - Jun 2018 |
Keywords
- Brown dwarfs
- Planets and satellites: formation
- Protoplanetary disks
- Stars: rotation
Fingerprint
Dive into the research topics of 'A universal spin-mass relation for brown dwarfs and planets'. Together they form a unique fingerprint.Projects
- 2 Finished
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Astronomy at St Andrews 2018-2021: Astronomy at St Andrews 2018-2021
Jardine, M. M. (PI), Bonnell, I. A. (CoI), Cameron, A. C. (CoI), Cyganowski, C. J. (CoI), Dominik, M. (CoI), Helling, C. (CoI), Horne, K. D. (CoI), Scholz, A. (CoI), Tojeiro, R. (CoI), Weijmans, A.-M. (CoI), Wild, V. (CoI), Woitke, P. (CoI), Wood, K. (CoI) & Zhao, H. (CoI)
1/04/18 → 31/03/22
Project: Standard
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Astronomy at St Andrews 2015-2018: Astronomy at St Andrews 2015-2018
Jardine, M. M. (PI), Cameron, A. C. (CoI), Cyganowski, C. J. (CoI), Horne, K. D. (CoI) & Wood, K. (CoI)
Science & Technology Facilities Council
1/04/15 → 31/03/18
Project: Standard
Profiles
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Alexander Scholz
- School of Physics and Astronomy - Director of the University Observatory and Reader
- St Andrews Centre for Exoplanet Science
Person: Academic