Space observations of AA Doradus provide consistent mass determinations. New HW-Vir systems observed with TESS

Baran AS, Ostensen RH, Heber U, Irrgang A, Sanjayan S, Telting JH, Reed MD, Ostrowski J (2021)

Publication Type: Journal article, Review article

Publication year: 2021

Journal

Monthly Notices of the Royal Astronomical Society Oxford University Press

Book Volume: 503

Pages Range: 2157-2167

Journal Issue: 2

DOI: 10.1093/mnras/stab620

Abstract

We present an overview of eclipsing systems of the HW-Virginis (HW-Vir) type, based on space observations from the Transiting Exoplanet Survey Satellite (TESS) mission. We perform a detailed analysis of the properties of AA Doradus (AA Dor), which was monitored for almost a full year. This excellent time series data set permitted us to search for both stellar pulsations and eclipse timing variations. In addition, we used the high-precision trigonometric parallax from Gaia Early Data Release 3 to make an independent determination of the fundamental stellar parameters. No convincing pulsations were detected down to a limit of 76 parts per million; however, we detected one peak with false alarm probability of 0.2 per cent. 20 s cadences being collected during Year 3 should confirm or reject our detection. From eclipse timing measurements we were able to confirm that the orbital period is stable, with an upper limit to any period change of 5.75 × 10−13 s s−1. The apparent offset of the secondary eclipse is consistent with the predicted Rømer delay when the primary mass is that of a canonical extended horizontal branch star. Using parallax and a spectral energy distribution corroborates that the mass of the primary in AA Dor is canonical, and its radius and luminosity are consistent with an evolutionary state beyond core helium burning. The mass of the secondary is found to be at the limit of hydrogen burning.

Authors with CRIS profile

Ulrich Heber Professur für Astronomie und Astrophysik Andreas Irrgang Dr.Karl-Remeis-Sternwarte Bamberg, Astronomisches Institut

Involved external institutions

Uniwersytet Pedagogiczny im. Komisji Edukacji Narodowej w Krakowie PL Poland (PL)

How to cite

APA:

Baran, A.S., Ostensen, R.H., Heber, U., Irrgang, A., Sanjayan, S., Telting, J.H.,... Ostrowski, J. (2021). Space observations of AA Doradus provide consistent mass determinations. New HW-Vir systems observed with TESS. Monthly Notices of the Royal Astronomical Society, 503(2), 2157-2167. https://doi.org/10.1093/mnras/stab620

MLA:

Baran, A. S., et al. "Space observations of AA Doradus provide consistent mass determinations. New HW-Vir systems observed with TESS." Monthly Notices of the Royal Astronomical Society 503.2 (2021): 2157-2167.

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