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arXiv · 2302.02696

A survey for variable young stars with small telescopes: VI -- Analysis of the outbursting Be stars NSW284, Gaia19eyy, and VES263

Dirk Froebrich·Lynne A. Hillenbrand·Carys Herbert·Kishalay De·Jochen Eislöffel·Justyn Campbell-White·Ruhee Kahar·Franz-Josef Hambsch·Thomas Urtly·Adam Popowicz·Krzysztof Bernacki·Andrzej Malcher·Slawomir Lasota·Jerzy Fiolka·Piotr Jozwik-Wabik·Franky Dubois·Ludwig Logie·Steve Rau·Mark Phillips·George Fleming·Rafael Gonzalez Farfán·Francisco C. Soldán Alfaro·Tim Nelson·Stephen R. L. Futcher·Samantha M. Rolfe·David A. Campbell·Tony Vale·Pat Devine·Dawid Moździerski·Przemysław J. Mikołajczyk·Heinz-Bernd Eggenstein·Diego Rodriguez·Ivan L Walton·Siegfried Vanaverbeke·Barry Merrikin·Yenal Öğmen·Alex Escartin Perez·Mario Morales Aimar·Georg Piehler·Lord Dover·Aashini L. Patel·Niall Miller·Jack Finch·Matt Hankins·Anna M. Moore·Tony Travouillon·Marek Szczepanski
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Abstract

This paper is one in a series reporting results from small telescope observations of variable young stars. Here, we study the repeating outbursts of three likely Be stars based on long-term optical, near-infrared, and mid-infrared photometry for all three objects, along with follow-up spectra for two of the three. The sources are characterised as rare, truly regularly outbursting Be stars. We interpret the photometric data within a framework for modelling light curve morphology, and find that the models correctly predict the burst shapes, including their larger amplitudes and later peaks towards longer wavelengths. We are thus able to infer the start and end times of mass loading into the circumstellar disks of these stars. The disk sizes are typically 3-6 times the areas of the central star. The disk temperatures are ~40%, and the disk luminosities are ~10% of those of the central Be star, respectively. The available spectroscopy is consistent with inside-out evolution of the disk. Higher excitation lines have larger velocity widths in their double-horned shaped emission profiles. Our observations and analysis support the decretion disk model for outbursting Be stars.

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Dirk Froebrich, Lynne A. Hillenbrand, Carys Herbert, Kishalay De, Jochen Eislöffel, Justyn Campbell-White, Ruhee Kahar, Franz-Josef Hambsch, Thomas Urtly, Adam Popowicz, Krzysztof Bernacki, Andrzej Malcher, Slawomir Lasota, Jerzy Fiolka, Piotr Jozwik-Wabik, Franky Dubois, Ludwig Logie, Steve Rau, Mark Phillips, George Fleming, Rafael Gonzalez Farfán, Francisco C. Soldán Alfaro, Tim Nelson, Stephen R. L. Futcher, Samantha M. Rolfe, David A. Campbell, Tony Vale, Pat Devine, Dawid Moździerski, Przemysław J. Mikołajczyk, Heinz-Bernd Eggenstein, Diego Rodriguez, Ivan L Walton, Siegfried Vanaverbeke, Barry Merrikin, Yenal Öğmen, Alex Escartin Perez, Mario Morales Aimar, Georg Piehler, Lord Dover, Aashini L. Patel, Niall Miller, Jack Finch, Matt Hankins, Anna M. Moore, Tony Travouillon, Marek Szczepanski. 2023-02-06. A survey for variable young stars with small telescopes: VI -- Analysis of the outbursting Be stars NSW284, Gaia19eyy, and VES263. https://doi.org/10.1093/mnras/stad407

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