GG Carinae: Discovery of orbital phase dependent 1.583-day periodicities in the B[e] supergiant binary

GG Carinae (GG Car) is a binary whose primary component is a B[e] supergiant. Using photometric data from the Transiting Exoplanet Survey Satellite (TESS), All Sky Automated Survey (ASAS), Optical Monitoring Camera (OMC), and All Sky Automated Survey for Supernovae (ASAS-SN), and spectroscopic data...

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Main Authors: Porter, A, Blundell, K, Podsiadlowski, P, lee, S
Format: Journal article
Language:English
Published: Oxford University Press 2021
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author Porter, A
Blundell, K
Podsiadlowski, P
lee, S
author_facet Porter, A
Blundell, K
Podsiadlowski, P
lee, S
author_sort Porter, A
collection OXFORD
description GG Carinae (GG Car) is a binary whose primary component is a B[e] supergiant. Using photometric data from the Transiting Exoplanet Survey Satellite (TESS), All Sky Automated Survey (ASAS), Optical Monitoring Camera (OMC), and All Sky Automated Survey for Supernovae (ASAS-SN), and spectroscopic data from the Global Jet Watch to study visible He I, Fe II, and Si II emission lines, we investigate the short-period variations that are exhibited in GG Car. We find a hitherto neglected periodicity of 1.583156 ± 0.0002 d that is present in both its photometry and the radial velocities of its emission lines, alongside variability at the well-established ∼31-d orbital period. We find that the amplitudes of the shorter period variations in both photometry and some of the emission lines are modulated by the orbital phase of the binary, such that the short-period variations have largest amplitudes when the binary is at periastron. There are no significant changes in the phases of the short-period variations over the orbital period. We investigate potential causes of the 1.583-d variability, and find that the observed period agrees well with the expected period of the l = 2 f-mode of the primary given its mass and radius. We propose that the primary is periodically pulled out of hydrostatic equilibrium by the quadrupolar tidal forces when the components are near periastron in the binary’s eccentric orbit (e = 0.5) and the primary almost fills its Roche lobe. This causes an oscillation at the l = 2 f-mode frequency that is damped as the distance between the components increases.
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spelling oxford-uuid:0507d60a-54cd-4f96-939e-d6e5524c1aa12022-03-26T08:54:59ZGG Carinae: Discovery of orbital phase dependent 1.583-day periodicities in the B[e] supergiant binaryJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:0507d60a-54cd-4f96-939e-d6e5524c1aa1EnglishSymplectic ElementsOxford University Press2021Porter, ABlundell, KPodsiadlowski, Plee, SGG Carinae (GG Car) is a binary whose primary component is a B[e] supergiant. Using photometric data from the Transiting Exoplanet Survey Satellite (TESS), All Sky Automated Survey (ASAS), Optical Monitoring Camera (OMC), and All Sky Automated Survey for Supernovae (ASAS-SN), and spectroscopic data from the Global Jet Watch to study visible He I, Fe II, and Si II emission lines, we investigate the short-period variations that are exhibited in GG Car. We find a hitherto neglected periodicity of 1.583156 ± 0.0002 d that is present in both its photometry and the radial velocities of its emission lines, alongside variability at the well-established ∼31-d orbital period. We find that the amplitudes of the shorter period variations in both photometry and some of the emission lines are modulated by the orbital phase of the binary, such that the short-period variations have largest amplitudes when the binary is at periastron. There are no significant changes in the phases of the short-period variations over the orbital period. We investigate potential causes of the 1.583-d variability, and find that the observed period agrees well with the expected period of the l = 2 f-mode of the primary given its mass and radius. We propose that the primary is periodically pulled out of hydrostatic equilibrium by the quadrupolar tidal forces when the components are near periastron in the binary’s eccentric orbit (e = 0.5) and the primary almost fills its Roche lobe. This causes an oscillation at the l = 2 f-mode frequency that is damped as the distance between the components increases.
spellingShingle Porter, A
Blundell, K
Podsiadlowski, P
lee, S
GG Carinae: Discovery of orbital phase dependent 1.583-day periodicities in the B[e] supergiant binary
title GG Carinae: Discovery of orbital phase dependent 1.583-day periodicities in the B[e] supergiant binary
title_full GG Carinae: Discovery of orbital phase dependent 1.583-day periodicities in the B[e] supergiant binary
title_fullStr GG Carinae: Discovery of orbital phase dependent 1.583-day periodicities in the B[e] supergiant binary
title_full_unstemmed GG Carinae: Discovery of orbital phase dependent 1.583-day periodicities in the B[e] supergiant binary
title_short GG Carinae: Discovery of orbital phase dependent 1.583-day periodicities in the B[e] supergiant binary
title_sort gg carinae discovery of orbital phase dependent 1 583 day periodicities in the b e supergiant binary
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AT podsiadlowskip ggcarinaediscoveryoforbitalphasedependent1583dayperiodicitiesinthebesupergiantbinary
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