%0 Generic %1 milespaez2017rotation %A Miles-Páez, P. A. %A Pallé, E. %A Osorio, M. R. Zapatero %D 2017 %K mdwarf rotation %T Rotation periods and photometric variability of rapidly rotating ultra-cool dwarfs %U http://arxiv.org/abs/1708.07777 %X We used the optical and near-infrared imagers located on the Liverpool, the IAC80, and the William Herschel telescopes to monitor 18 M7$-$L9.5 dwarfs with the objective of measuring their rotation periods. We achieved accuracies typically in the range $\pm$1.5$-$28 mmag by means of differential photometry, which allowed us to detect photometric variability at the 2$\sigma$ level in the 50\% of the sample. We also detected periodic modulation with periods in the interval 1.5$-$4.4 h in 9 out of 18 dwarfs that we attribute to rotation. Our variability detections were combined with data from the literature; we found that 65$\,\pm\,$18 $\%$ of M7$-$L3.5 dwarfs with $v\,$sin$\,i\ge30$ km s$^-1$ exhibit photometric variability with typical amplitudes $łe$20 mmag in the $I$-band. For those targets and field ultra-cool dwarfs with measurements of $v\,$sin$\,i$ and rotation period we derived the expected inclination angle of their rotation axis, and found that those with $v\,$sin$\,i\ge30$ km s$^-1$ are more likely to have inclinations $\gtrsim40$ deg. In addition, we used these rotation periods and others from the literature to study the likely relationship between rotation and linear polarization in dusty ultra-cool dwarfs. We found a correlation between short rotation periods and large values of linear polarization at optical and near-infrared wavelengths.

@misc{milespaez2017rotation, abstract = {We used the optical and near-infrared imagers located on the Liverpool, the IAC80, and the William Herschel telescopes to monitor 18 M7$-$L9.5 dwarfs with the objective of measuring their rotation periods. We achieved accuracies typically in the range $\pm$1.5$-$28 mmag by means of differential photometry, which allowed us to detect photometric variability at the 2$\sigma$ level in the 50\% of the sample. We also detected periodic modulation with periods in the interval 1.5$-$4.4 h in 9 out of 18 dwarfs that we attribute to rotation. Our variability detections were combined with data from the literature; we found that 65$\,\pm\,$18 $\%$ of M7$-$L3.5 dwarfs with $v\,$sin$\,i\ge30$ km s$^{-1}$ exhibit photometric variability with typical amplitudes $\le$20 mmag in the $I$-band. For those targets and field ultra-cool dwarfs with measurements of $v\,$sin$\,i$ and rotation period we derived the expected inclination angle of their rotation axis, and found that those with $v\,$sin$\,i\ge30$ km s$^{-1}$ are more likely to have inclinations $\gtrsim40$ deg. In addition, we used these rotation periods and others from the literature to study the likely relationship between rotation and linear polarization in dusty ultra-cool dwarfs. We found a correlation between short rotation periods and large values of linear polarization at optical and near-infrared wavelengths.}, added-at = {2017-08-29T16:43:17.000+0200}, author = {Miles-Páez, P. A. and Pallé, E. and Osorio, M. R. Zapatero}, biburl = {https://www.bibsonomy.org/bibtex/2ee5ca429482e7766e1b771e6badc69d1/superjenwinters}, description = {Rotation periods and photometric variability of rapidly rotating ultra-cool dwarfs}, interhash = {8456a814d169145cb92ae130d657bcce}, intrahash = {ee5ca429482e7766e1b771e6badc69d1}, keywords = {mdwarf rotation}, note = {cite arxiv:1708.07777Comment: 19 pages, 12 figures, accepted for publication in MNRAS}, timestamp = {2017-08-29T16:43:17.000+0200}, title = {Rotation periods and photometric variability of rapidly rotating ultra-cool dwarfs}, url = {http://arxiv.org/abs/1708.07777}, year = 2017 }