J/MNRAS/474/4322 Orbital parameters of 341 new binaries (Murphy+, 2018)
Finding binaries from phase modulation of pulsating stars with Kepler:
V. Orbital parameters, with eccentricity and mass-ratio distributions
of 341 new binaries.
Murphy S.J., Moe M., Kurtz D.W., Bedding T., Shibahashi H., Boffin H.M.J.
<Mon. Not. R. Astron. Soc. 474, 4322 (2018)>
=2018MNRAS.474.4322M 2018MNRAS.474.4322M (SIMBAD/NED BibCode)
ADC_Keywords: Stars, double and multiple ; Stars, variable
Keywords: binaries: general - blue stragglers - stars: formation -
stars: oscillations - stars: statistics -
stars: variables: delta Scuti
Abstract:
The orbital parameters of binaries at intermediate periods
(102-103d) are difficult to measure with conventional methods and
are very incomplete. We have undertaken a new survey, applying our
pulsation timing method to Kepler light curves of 2224 main-sequence
A/F stars and found 341 non-eclipsing binaries. We calculate the
orbital parameters for 317 PB1 systems (single-pulsator binaries) and
24 PB2s (double-pulsators), tripling the number of intermediate-mass
binaries with full orbital solutions. The method reaches down to small
mass ratios q∼0.02 and yields a highly homogeneous sample. We
parametrize the mass-ratio distribution using both inversion and MCMC
forward-modelling techniques, and find it to be skewed towards
low-mass companions, peaking at q∼0.2.
While solar-type primaries exhibit a brown dwarf desert across short
and intermediate periods, we find a small but statistically
significant (2.6σ) population of extreme-mass-ratio companions
(q<0.1) to our intermediate-mass primaries.
Across periods of 100-1500d and at q>0.1, we measure the binary
fraction of current A/F primaries to be 15.4%±1.4%, though we find
that a large fraction of the companions (21%±6%) are white dwarfs in
post-mass-transfer systems with primaries that are now blue
stragglers, some of which are the progenitors of Type Ia supernovae,
barium stars, symbiotics, and related phenomena.
Excluding these white dwarfs, we determine the binary fraction of
original A/F primaries to be 13.9%±2.1% over the same parameter
space. Combining our measurements with those in the literature, we
find the binary fraction across these periods is a constant 5% for
primaries M1<0.8M☉, but then increases linearly with logM1,
demonstrating that natal discs around more massive protostars
M1≳1M☉ become increasingly more prone to fragmentation.
Finally, we find the eccentricity distribution of the main-sequence
pairs to be much less eccentric than the thermal distribution.
Description:
Kepler targets with effective temperatures between 6600 and 10000K
have been investigated for pulsational phase modulation that can be
attributed to binary orbital motion. For each target, we provide a
binary status, which also reflects whether or not the target pulsates.
For the binary systems, we provide the Kepler Input Catalogue (KIC)
number, as well as the binary orbital elements: the period, semi-major
axis, eccentricity, longitude of periastron, time of periastron
passage, binary mass function and a calculated radial velocity
semi-amplitude.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
classes.dat 10 12649 Pulsation and binary classification of targets
orbits1.dat 169 315 Orbits for single-pulsator binaries (table 2)
orbits2.dat 200 24 Orbits for double-pulsator binaries (table 3)
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See also:
V/133 : Kepler Input Catalog (Kepler Mission Team, 2009)
Byte-by-byte Description of file: classes.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 8 I8 --- KIC Kepler Input Catalogue (KIC) number
10 A1 --- Class [0-7] Numbered classification (1)
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Note (1): Classifications of pulsators and binaries in accordance with
Table 1 of the journal article, as follows:
0 = Eclipsing or ellipsoidal variable
1 = RR Lyrae stars
2 = No p modes (or weak p modes)
3 = Insufficient data to classify binarity
4 = Single (not PB1 or PB2)
5 = Possible long period binary, period much longer than dataset
6 = Single-pulsator or double-pulsator binary (PB1 or PB2)
7 = Systems that were found to be single in the PM survey and hence in our
statistics, but were found to be (mostly short-period) binaries by other
methods and now have PM orbital solutions
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Byte-by-byte Description of file: orbits1.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 8 I8 --- KIC Kepler Input Catalogue (KIC) number
9 A1 --- m_KIC [ab] Multiplicity index on KIC
11- 18 F8.3 d P Orbital period
20- 27 F8.3 d E_P Orbital period uncertainty (pos) (1)
29- 35 F7.3 d e_P Orbital period uncertainty (neg) (1)
37- 43 F7.2 s a1 Projected semi-major axis of primary
45- 50 F6.2 s E_a1 Projected semi-major axis uncertainty (pos) (1)
52- 57 F6.2 s e_a1 Projected semi-major axis uncertainty (neg) (1)
59- 64 F6.4 --- e Eccentricity
66- 71 F6.4 --- E_e Eccentricity uncertainty (pos) (1)
73- 78 F6.4 --- e_e Eccentricity uncertainty (neg) (1)
80- 84 F5.3 rad w Longitude of periastron
86- 90 F5.3 rad E_w Longitude of periastron uncertainty (pos) (1)
92- 96 F5.3 rad e_w Longitude of periastron uncertainty (neg) (1)
98-107 F10.2 d tp Time of periastron passage (BJD) (2)
109-115 F7.2 d E_tp Time of periastron passage uncertainty (pos) (1)
117-123 F7.2 d e_tp Time of periastron passage uncertainty (neg) (1)
125-131 E7.5 Msun fM Binary mass function
133-139 F7.5 Msun E_fM Binary mass function uncertainty (pos) (1)
141-147 F7.5 Msun e_fM Binary mass function uncertainty (neg) (1)
149-155 F7.4 km/s K1 Radial Velocity of primary (3)
157-162 F6.4 km/s E_K1 Radial Velocity uncertainty (pos) (1)
164-169 F6.4 km/s e_K1 Radial Velocity uncertainty (neg) (1)
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Note (1): Uncertainties are presented as one-sided one-sigma values.
Note (2): Times of periastron passage are in barycentric Julian date
Note (3): Units of radial velocity are kilometres per second
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Byte-by-byte Description of file: orbits2.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 8 I8 --- KIC Kepler Input Catalogue (KIC) number
10- 17 F8.3 d P Orbital period
19- 26 F8.3 d E_P Orbital period uncertainty (pos) (1)
28- 35 F8.3 d e_P Orbital period uncertainty (neg) (1)
37- 42 F6.1 s a1 Projected semi-major axis of primary
44- 48 F5.1 s E_a1 Projected semi-major axis uncertainty (pos) (1)
50- 54 F5.1 s e_a1 Projected semi-major axis uncertainty (neg) (1)
56- 61 F6.4 --- e Eccentricity
63- 68 F6.4 --- E_e Eccentricity uncertainty (pos) (1)
70- 75 F6.4 --- e_e Eccentricity uncertainty (neg) (1)
77- 81 F5.3 rad w Longitude of periastron
83- 87 F5.3 rad E_w Longitude of periastron uncertainty (pos) (1)
89- 93 F5.3 rad e_w Longitude of periastron uncertainty (neg) (1)
95-103 F9.1 d tp Time of periastron passage (BJD) (2)
105-110 F6.1 d E_tp Time of periastron passage uncertainty (pos) (1)
112-117 F6.1 d e_tp Time of periastron passage uncertainty (neg) (1)
119-125 E7.2 Msun fM Binary mass function
127-133 F7.5 Msun E_fM Binary mass function uncertainty (pos) (1)
135-141 F7.5 Msun e_fM Binary mass function uncertainty (neg) (1)
143-148 F6.3 km/s K1 Radial Velocity of primary (3)
150-154 F5.3 km/s E_K1 Radial Velocity uncertainty (pos) (1)
156-160 F5.3 km/s e_K1 Radial Velocity uncertainty (neg) (1)
162-167 F6.1 s a2 Projected semi-major axis of secondary
169-173 F5.1 s E_a2 Projected semi-major axis uncertainty (pos) (1)
175-179 F5.1 s e_a2 Projected semi-major axis uncertainty (neg) (1)
181-186 F6.4 --- q Binary mass ratio
188-193 F6.4 --- E_q Binary mass ratio uncertainty (pos) (1)
195-200 F6.4 --- e_q Binary mass ratio uncertainty (neg) (1)
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Note (1): Uncertainties are presented as one-sided one-sigma values.
Note (2): Times of periastron passage are in barycentric Julian date
Note (3): Units of radial velocity are kilometres per second
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Acknowledgements:
Simon J. Murphy, simon.murphy(at)sydney.edu.au
References:
Murphy et al., Paper I 2014MNRAS.441.2515M 2014MNRAS.441.2515M
Murphy et al., Paper IV 2016MNRAS.461.4215M 2016MNRAS.461.4215M
(End) Simon J. Murphy [USyd, Australia], Patricia Vannier [CDS] 04-Jan-2018