1. Complex Modulation of Rapidly Rotating Young M Dwarfs:Adding Pieces to the Puzzle
- Author
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Günther, Maximilian N., Berardo, David A., Ducrot, Elsa, Murray, Catriona A., Stassun, Keivan G., Olah, Katalin, Bouma, L. G., Rappaport, Saul, Winn, Joshua N., Feinstein, Adina D., Matthews, Elisabeth C., Sebastian, Daniel, Rackham, Benjamin V., Seli, Bálint, J. Triaud, Amaury H. M., Gillen, Edward, Levine, Alan M., Demory, Brice-Olivier, Gillon, Michaël, Queloz, Didier, Ricker, George R., Vanderspek, Roland K., Seager, Sara, Latham, David W., Jenkins, Jon M., Brasseur, C. E., Colón, Knicole D., Daylan, Tansu, Delrez, Laetitia, Fausnaugh, Michael, Garcia, Lionel J., Jayaraman, Rahul, Jehin, Emmanuel, Kristiansen, Martti H., Kruijssen, J. M. Diederik, Pedersen, Peter Pihlmann, Pozuelos, Francisco J., Rodriguez, Joseph E., Wohler, Bill, Zhan, Zhuchang, Günther, MN [0000-0002-3164-9086], Berardo, DA [0000-0001-6298-412X], Ducrot, E [0000-0002-7008-6888], Murray, CA [0000-0001-8504-5862], Stassun, KG [0000-0002-3481-9052], Olah, K [0000-0003-3669-7201], Bouma, LG [0000-0002-0514-5538], Rappaport, S [0000-0003-3182-5569], Winn, JN [0000-0002-4265-047X], Feinstein, AD [0000-0002-9464-8101], Matthews, EC [0000-0003-0593-1560], Sebastian, D [0000-0002-2214-9258], Rackham, BV [0000-0002-3627-1676], Seli, B [0000-0002-3658-2175], Amaury, AHM [0000-0002-5510-8751], Gillen, E [0000-0003-2851-3070], Levine, AM [0000-0001-8172-0453], Demory, BO [0000-0002-9355-5165], Gillon, M [0000-0003-1462-7739], Queloz, D [0000-0002-3012-0316], Ricker, GR [0000-0003-2058-6662], Vanderspek, RK [0000-0001-6763-6562], Seager, S [0000-0002-6892-6948], Latham, DW [0000-0001-9911-7388], Jenkins, JM [0000-0002-4715-9460], Brasseur, CE [0000-0002-9314-960X], Colón, KD [0000-0001-8020-7121], Daylan, T [0000-0002-6939-9211], Delrez, L [0000-0001-6108-4808], Fausnaugh, M [0000-0002-9113-7162], Garcia, LJ [0000-0002-4296-2246], Jayaraman, R [0000-0002-7778-3117], Jehin, E [0000-0001-8923-488X], Kristiansen, MH [0000-0002-2607-138X], Kruijssen, JMD [0000-0002-8804-0212], Pedersen, PP [0000-0002-5220-609X], Pozuelos, FJ [0000-0003-1572-7707], Rodriguez, JE [0000-0001-8812-0565], Wohler, B [0000-0002-5402-9613], Zhan, Z [0000-0002-4142-1800], and Apollo - University of Cambridge Repository
- Subjects
Earth and Planetary Astrophysics (astro-ph.EP) ,astro-ph.SR ,Variable stars ,520 Astronomy ,FOS: Physical sciences ,Astronomy and Astrophysics ,Stellar flares ,Astrophysics::Cosmology and Extragalactic Astrophysics ,M dwarf stars ,Starspots ,Astrophysics - Solar and Stellar Astrophysics ,Space and Planetary Science ,astro-ph.EP ,Periodic variable stars ,Astrophysics::Solar and Stellar Astrophysics ,Astrophysics::Earth and Planetary Astrophysics ,T Tauri stars ,Stellar rotation ,Pre-main sequence stars ,Solar and Stellar Astrophysics (astro-ph.SR) ,Astrophysics::Galaxy Astrophysics ,Astrophysics - Earth and Planetary Astrophysics ,Stellar activity - Abstract
New sets of young M dwarfs with complex, sharp-peaked, and strictly periodic photometric modulations have recently been discovered with Kepler/K2 (scallop shells) and TESS (complex rotators). All are part of star-forming associations, are distinct from other variable stars, and likely belong to a unified class. Suggested hypotheses include star spots, accreting dust disks, co-rotating clouds of material, magnetically constrained material, spots and misaligned disks, and pulsations. Here, we provide a comprehensive overview and add new observational constraints with TESS and SPECULOOS Southern Observatory (SSO) photometry. We scrutinize all hypotheses from three new angles: (1) we investigate each scenario's occurrence rates via young star catalogs; (2) we study the features' longevity using over one year of combined data; and (3) we probe the expected color dependency with multi-color photometry. In this process, we also revisit the stellar parameters accounting for activity effects, study stellar flares as activity indicators over year-long time scales, and develop toy models to simulate typical morphologies. We rule out most hypotheses, and only (i) co-rotating material clouds and (ii) spots and misaligned disks remain feasible - with caveats. For (i), co-rotating dust might not be stable enough, while co-rotating gas alone likely cannot cause percentage-scale features; and (ii) would require misaligned disks around most young M dwarfs. We thus suggest a unified hypothesis, a superposition of large-amplitude spot modulations and sharp transits of co-rotating gas clouds. While the complex rotators' mystery remains, these new observations add valuable pieces to the puzzle going forward., Comment: Accepted in The Astronomical Journal, 23 pages, 14 figures, 2 tables. This is the authors' version of the manuscript
- Published
- 2022