J/other/NatAs/3.760 Blue supergiants low-frequency gravity waves (Bowman+, 2019)
Low-frequency gravity waves in blue supergiants revealed by high-precision
space photometry.
Bowman D.M., Burssens S., Pedersen M.G., Johnston C., Aerts C.,
Buysschaert B., Michielsen M., Tkachenko A., Rogers T.M., Edelmann P.V.F.,
Ratnasingam R.P., Simon-Diaz S., Castro N., Moravveji E., Pope B.J.S.,
White T.R., De Cat P.
<Nature Astronomy, 3, 760-765 (2019)>
=2019NatAs...3..760B 2019NatAs...3..760B (SIMBAD/NED BibCode)
ADC_Keywords: Stars, supergiant ; Blue objects ; Stars, variable ;
Asteroseismology ; Optical
Abstract:
Almost all massive stars explode as supernovae and form a black hole
or neutron star. The remnant mass and the impact of the chemical yield
on subsequent star formation and galactic evolution strongly depend on
the internal physics of the progenitor star, which is currently not
well understood. The theoretical uncertainties of stellar interiors
accumulate with stellar age, which is particularly pertinent for the
blue supergiant phase. Stellar oscillations represent a unique method
of probing stellar interiors, yet inference for blue supergiants is
hampered by a dearth of observed pulsation modes. Here we report the
detection of diverse variability in blue supergiants using the K2 and
TESS space missions. The discovery of pulsation modes or an entire
spectrum of low-frequency gravity waves in these stars allow us to map
the evolution of hot massive stars towards the ends of their lives.
Future asteroseismic modelling will provide constraints on ages, core
masses, interior mixing, rotation and angular momentum transport. The
discovery of variability in blue supergiants is a step towards a
data-driven empirical calibration of theoretical evolution models for
the most massive stars in the Universe.
Description:
We assembled a sample of 114 ecliptic stars and 53 Large Magellanic
Cloud (LMC) stars of spectral type O or B with available K2 and TESS
space photometry, respectively.
We provide the fit parameters α0, νchar and γ used
to characterize the morphology of the stochastic low-frequency
variability in the residual amplitude spectra of 111 K2 ecliptic stars
and the original amplitude spectra of 53 TESS LMC stars
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
tabled1.dat 87 114 Parameters of the 114 OB stars observed by
the K2 space mission
tabled2.dat 87 53 Parameters of 53 OB stars in the LMC observed by
the TESS space mission
tabled3.dat 73 114 Fit parameters of residual amplitude spectra
of K2 OB stars
tabled4.dat 73 53 Fit parameters of amplitude spectra
of TESS LMC OB stars
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See also:
IV/34 : K2 Ecliptic Plane Input Catalog (EPIC) (Huber+, 2017)
IV/38 : TESS Input Catalog - v8.0 (TIC-8) (Stassun+, 2019)
Byte-by-byte Description of file: tabled1.dat tabled2.dat
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Bytes Format Units Label Explanations
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1- 9 I9 --- Name EPIC (tabled1) or TESS (tabled2) (1)
11- 29 I19 --- GaiaDR2 Gaia DR2 source_id (some erroneous numbers)
31- 44 A14 --- SpType Spectral type
46- 51 F6.3 mag BP-RP Gaia Bp-RP colour index
53- 58 F6.3 mag GMAG Absolute Gaia G magnitude
60- 77 A18 --- VClass Variability class
79- 87 A9 --- VClassL Literature Variability class
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Note (1): In table d1, EPIC 200069370 not in the EPIC catalog.
EPIC 200182931 (Gaia DR2 3870025847369434624) not in the EPIC and
Gaia DR2 catalogs.
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Byte-by-byte Description of file: tabled3.dat tabled4.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 9 I9 --- Name EPIC (tabled2) or TESS (tabled4)
11- 19 F9.3 --- alpha0 ? Amplitude at a frequency of zero
21- 25 F5.3 --- e_alpha0 ? Amplitude at a frequency of zero error
27- 34 F8.5 --- nu-char ? Characteristic frequency
36- 42 F7.5 --- e_nu-char ? Characteristic frequency error
44- 51 F8.5 --- gamma ? logarithmic amplitude gradient
53- 59 F7.5 --- e_gamma ? logarithmic amplitude gradient error
61- 67 F7.3 --- C Frequency-independent noise term
69- 73 F5.3 --- e_C Frequency-independent noise term error
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 08-Aug-2023