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A survey for variable young stars with small telescopes – VIII. Properties of 1687 Gaia selected members in 21 nearby clusters

2024; Oxford University Press; Volume: 529; Issue: 2 Linguagem: Inglês

10.1093/mnras/stae311

1365-2966

D. Froebrich, A. Scholz, J. Campbell-White, S. Vanaverbeke, Carys Herbert, J. Eislöffel, Thomas Urtly, Timothy P Long, Ivan L Walton, K. Wiersema, Nick Quinn, Tony Rodda, Juan-Luis González-Carballo, Mario Morales Aimar, Rafael Castillo García, Francisco C Soldán Alfaro, Faustino García de la Cuesta, Domenico Licchelli, Alex Escartin Perez, José Luis Salto González, Marc Deldem, Stephen R L Futcher, Tim Nelson, Shawn Dvorak, D. Moździerski, Krzysztof Kotysz, P. Mikołajczyk, George Fleming, M. W. Phillips, Tony Vale, Y. Öǧmen, Franky Dubois, Samantha Rolfe, David A. Campbell, H.-B. Eggenstein, Franz-Josef Hambsch, Michael A Heald, Pablo Lewin, Adam C. Rose, G. Stone, Martin Valentine Crow, Simon Francis Dawes, Derek OKeeffe, Adam Popowicz, Krzysztof Bernacki, Andrzej Malcher, Sławomir Lasota, Jerzy Fiołka, Adam Dustor, Amritanshu Vajpayee, Pat Devine, Matthias Kolb, J. B. Marquette, Gregg Ruppel, Dan Crowson, Cledison Marcos da Silva, Michel Michaud, Aashini L Patel, Matthew D. Dickers, Lord Dover, Ivana I. Grozdanova, J. S. Urquhart, Chris J R Lynch,

Astro and Planetary Science

ABSTRACT The Hunting Outbursting Young Stars (HOYS) project performs long-term, optical, multifilter, high cadence monitoring of 25 nearby young clusters and star-forming regions. Utilizing Gaia DR3 data, we have identified about 17 000 potential young stellar members in 45 coherent astrometric groups in these fields. Twenty one of them are clear young groups or clusters of stars within 1 kpc and they contain 9143 Gaia selected potential members. The cluster distances, proper motions, and membership numbers are determined. We analyse long-term (≈ 7 yr) V-, R-, and I-band light curves from HOYS for 1687 of the potential cluster members. One quarter of the stars are variable in all three optical filters, and two-thirds of these have light curves that are symmetric around the mean. Light curves affected by obscuration from circumstellar materials are more common than those affected by accretion bursts, by a factor of 2–4. The variability fraction in the clusters ranges from 10 per cent to almost 100 per cent, and correlates positively with the fraction of stars with detectable inner discs, indicating that a lot of variability is driven by the disc. About one in six variables shows detectable periodicity, mostly caused by magnetic spots. Two-thirds of the periodic variables with disc excess emission are slow rotators, and amongst the stars without disc excess two-thirds are fast rotators – in agreement with rotation being slowed down by the presence of a disc.