EX draconis: using eclipses to separate outside-in and inside-out outbursts
EX draconis: using eclipses to separate outside-in and inside-out outbursts
We present a study of the eclipses in the accreting white dwarf EX draconis (EX Dra) during TESS Cycles 14 and 15. During both of the two outbursts present in this data set, the eclipses undergo a hysteretic loop in eclipse-depth/out-of-eclipse-flux space. In each case, the direction in which the loops are executed strongly suggests an outburst that is triggered near the inner edge of the accretion disc and propagates outwards. This in turn suggests that the outbursts in EX Dra are ‘inside out’ outbursts; events predicted by previous hydrodynamic studies of dwarf nova accretion discs and confirmed spectroscopically in a number of other accreting white dwarf systems. We therefore propose that the direction of the loop executed in eclipse-depth/out-of-eclipse flux space be used as a test to phenomenologically distinguish between ‘inside out’ and ‘outside in’ outbursts in other eclipsing dwarf novae; a reliable and purely photometric test to differentiate between these phenomena.
accretion, accretion discs, eclipses, novae, cataclysmic variables, stars: Individual: EX Dra
4656-4664
Court, J M C
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Scaringi, S
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Littlefield, C
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Castro segura, N
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Long, K S
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Maccarone, T
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Altamirano, D
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Degenaar, N
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Wijnands, R
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Shahbaz, T
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Zhan, Z
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1 June 2020
Court, J M C
6e39b3e2-c269-49eb-9e06-cc47981117f1
Scaringi, S
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Littlefield, C
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Castro segura, N
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Long, K S
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Maccarone, T
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Altamirano, D
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Degenaar, N
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Wijnands, R
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Shahbaz, T
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Zhan, Z
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Court, J M C, Scaringi, S, Littlefield, C, Castro segura, N, Long, K S, Maccarone, T, Altamirano, D, Degenaar, N, Wijnands, R, Shahbaz, T and Zhan, Z
(2020)
EX draconis: using eclipses to separate outside-in and inside-out outbursts.
Monthly Notices of the Royal Astronomical Society, 494 (4), .
(doi:10.1093/mnras/staa1042).
Abstract
We present a study of the eclipses in the accreting white dwarf EX draconis (EX Dra) during TESS Cycles 14 and 15. During both of the two outbursts present in this data set, the eclipses undergo a hysteretic loop in eclipse-depth/out-of-eclipse-flux space. In each case, the direction in which the loops are executed strongly suggests an outburst that is triggered near the inner edge of the accretion disc and propagates outwards. This in turn suggests that the outbursts in EX Dra are ‘inside out’ outbursts; events predicted by previous hydrodynamic studies of dwarf nova accretion discs and confirmed spectroscopically in a number of other accreting white dwarf systems. We therefore propose that the direction of the loop executed in eclipse-depth/out-of-eclipse flux space be used as a test to phenomenologically distinguish between ‘inside out’ and ‘outside in’ outbursts in other eclipsing dwarf novae; a reliable and purely photometric test to differentiate between these phenomena.
Text
2004.06802
- Accepted Manuscript
More information
Accepted/In Press date: 9 April 2020
e-pub ahead of print date: 24 April 2020
Published date: 1 June 2020
Keywords:
accretion, accretion discs, eclipses, novae, cataclysmic variables, stars: Individual: EX Dra
Identifiers
Local EPrints ID: 442345
URI: http://eprints.soton.ac.uk/id/eprint/442345
ISSN: 1365-2966
PURE UUID: 54e9af92-8a57-4a8d-9f75-60c7d0ac5157
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Date deposited: 14 Jul 2020 16:30
Last modified: 17 Mar 2024 03:34
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Contributors
Author:
J M C Court
Author:
S Scaringi
Author:
C Littlefield
Author:
N Castro segura
Author:
K S Long
Author:
T Maccarone
Author:
N Degenaar
Author:
R Wijnands
Author:
T Shahbaz
Author:
Z Zhan
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