... rotation

Based on observations collected at the European Southern Observatory, La Silla, Chile (program numbers 54.D-0363 and 68.C-0348).

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...

Visiting Astronomer, Kitt Peak National Observatory, National Optical Astronomy Observatory, which is operated by the Association of Universities for Research in Astronomy, Inc. (AURA) under cooperative agreement with the National Science Foundation.

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... position

${\rm Centroid~position} = \frac{\int v I_{\rm cs}(v) {\rm d}v}{\int I_{\rm cs}(v) {\rm d}v}$ with $I_{\rm cs}$ the continuum-subtracted intensity of the profile and v the velocity parameter.

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... line

$\mathcal{C}=(\mathcal{R}+\mathcal{B})/2$.

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... Keplerian

The IDL code keprot.pro, which converts an intensity-versus-radius profile into an intensity-versus-velocity profile, can be downloaded at http://www.ster.kuleuven.ac.be/~bram/OI/keprot.pro http://www.ster.kuleuven.ac.be/~bram/OI/keprot.README

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... function

The IDL code convolve.pro, which convolves an intensity-versus-velocity profile with a Gaussian function, can be downloaded at http://www.ster.kuleuven.ac.be/~bram/OI/convolve.pro http://www.ster.kuleuven.ac.be/~bram/OI/convolve.README

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... sources

Hillenbrand et al. have defined their groups based on the near-IR spectral slope. There is no direct link between both classifications: Hillenbrand group I and II contain Meeus group I as well as group II sources.

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