{"references": ["Baglin, A. 1972, A&A, 19, 45", "Balona, L. A. 2013, MNRAS, 431, 2240", "Balona, L. A. 2017, MNRAS, 467, 1830", "Balona, L. A., Baran, A. S., Daszynska-Daszkiewicz, J., & De Cat, P. 2015, MNRAS, 451, 1445", "Berthomieu, G. & Provost, J. 1983, A&A, 122, 199.", "Bouabid, M.-P., Dupret, M.-A., Salmon, S., Montalb\u00e1n, J., Miglio, A., et al. 2013, MNRAS, 429, 2500", "Boyajian, T. S., LaCourse, D. M., Rappaport, S. A., Fabrycky, D., Fischer, D. A., et al. 2016, MNRAS, 457, 3988", "Chote, P. & Sullivan, D. J. 2016, MNRAS, 458, 1393", "Copperwheat, C. M., Marsh, T. R., Dhillon, V. S., Littlefair, S. P., Woudt, P. A., et al. 2009, MNRAS, 393, 157", "Dziembowski, W. & Kosovichev, A. 1987, AcA, 37, 313", "Dziembowski, W. A., Daszynska-Daszkiewicz, J., & Pamyatnykh, A. A. 2007, MNRAS, 374, 248", "H\u00fcmmerich, S., Niemczura, E., Walczak, P., Paunzen, E., Bernhard, K., et al. 2018, MNRAS, 474, 2467", "Lee, U. 2006, MNRAS, 365, 677", "Lee, U. & Saio, H. 1987, MNRAS, 224, 513", "Lee, U. & Saio, H. 1997, ApJ, 491, 839", "Monnier, J. D., Townsend, R. H. D., Che, X., Zhao, M., Kallinger, T., et al. 2010, ApJ, 725, 1192", "Mukadam, A. S., Townsley, D. M., Szkody, P., G\u00e4nsicke, B. T., Southworth, J., et al. 2013, AJ, 146, 54", "Mukadam, A. S., Townsley, D. M., Szkody, P., G\u00e4nsicke, B. T., Winget, D. E., et al. 2011, ApJ, 728, L33", "Murphy, S. J., Bedding, T. R., Niemczura, E., Kurtz, D. W., & Smalley, B. 2015, MNRAS, 447, 3948", "Niemczura, E., Murphy, S. J., Smalley, B., Uytterhoeven, K., Pigulski, A., et al. 2015, MNRAS, 450, 2764", "Ouazzani, R.-M., Salmon, S. J. A. J., Antoci, V., Bedding, T. R., Murphy, S. J., et al. 2017, MNRAS, 465, 2294", "Papaloizou, J. & Pringle, J. E. 1978, MNRAS, 182, 423", "P\u00e1pics, P. I., Tkachenko, A., Van Reeth, T., Aerts, C., Moravveji, E., et al. 2017, A&A, 598, A74", "Provost, J., Berthomieu, G., & Rocca, A. 1981, A&A, 94, 126", "Saio, H. 1982, ApJ, 256, 717", "Saio, H., Bedding, T. R., Kurtz, D. W., Murphy, S. J., Antoci, V., et al. 2018a, MNRAS, 477, 2183", "Saio, H., Kurtz, D. W., Murphy, S. J., Antoci, V. L., & Lee, U. 2018b, MNRAS, 474, 2774", "Savonije, G. J. 2005, A&A, 443, 557", "Smalley, B., Kurtz, D. W., Smith, A. M. S., Fossati, L., Anderson, D. R., et al. 2011, A&A, 535, A3", "Szkody, P., G\u00e4nsicke, B. T., Howell, S. B., & Sion, E. M. 2002, ApJ, 575, L79", "Szkody, P., Mukadam, A. S., G\u00e4nsicke, B. T., Henden, A., Sion, E. M., et al. 2012, ApJ, 753, 158", "Szkody, P., Mukadam, A. S., G\u00e4nsicke, B. T., Hermes, J. J., & Toloza, O. 2015, In 19th European Workshop on White Dwarfs, edited by P. Dufour, P. Bergeron, & G. Fontaine, Astronomical Society of the Pacic Conference Series, vol. 493, p. 205", "Szkody, P., Mukadam, A. S., G\u00e4nsicke, B. T., Sion, E. M., Townsley, D., et al. 2013, In 18th European White Dwarf Workshop., Astronomical Society of the Pacic Conference Series, vol. 469, p. 31", "Townsend, R. H. D. 2003, MNRAS, 340, 1020", "Townsend, R. H. D. 2005, MNRAS, 364, 573", "Unno,W., Osaki, Y., Ando, H., Saio, H., & Shibahashi, H. 1989, Nonradial oscillations of stars", "Van Reeth, T., Tkachenko, A., & Aerts, C. 2016, A&A, 593, A120", "van Spaandonk, L., Steeghs, D., Marsh, T. R., & Parsons, S. G. 2010, ApJ, 715, L109", "van Zyl, L., Warner, B., O'Donoghue, D., Hellier, C., Woudt, P., et al. 2004, MNRAS, 350, 307", "Warner, B. & van Zyl, L. 1998, In New Eyes to See Inside the Sun and Stars, edited by F.-L. Deubner, J. Christensen- Dalsgaard, & D. Kurtz, IAU Symposium, vol. 185, p. 321", "Zwintz, K., Van Reeth, T., Tkachenko, A., G\u00f6ssl, S., Pigulski, A., et al. 2017, A&A, 608, A103"]}

We discuss properties and examples of r-mode (large scale Rossby wave) oscillations in rotating stars. Motions are nearly toroidal but affected weakly by buoyancy. R modes seem to be excited mechanically in most cases, and ubiquitous in various types of rotating stars;e.g., fast rotating $\gamma$ Dor stars, spotted stars, eclipsing binary stars, Be stars, and accreting white dwarfs. In the Fourier spectrum of a star, even (i.e., symmetric to the equator) r modes of azimuthal order $m$ appear as a group of frequencies just below $m$ times the rotation frequency. From this property, a rotation frequency can be determined if r modes are detected. We discuss r modes in KIC~8462852 (Boyajian's star), KIC~9117875 (Am star), KIC~6128830 (HgMn star), and the accreting white dwarf in the dwarf nova GW~Lib.