J/AJ/159/19 SOAR TESS survey. I. (Ziegler+, 2020)
SOAR TESS survey.
I. Sculpting of TESS planetary systems by stellar companions.
Ziegler C., Tokovinin A., Briceno C., Mang J., Law N., Mann A.W.
<Astron. J., 159, 19 (2020)>
=2020AJ....159...19Z 2020AJ....159...19Z (SIMBAD/NED BibCode)
ADC_Keywords: Stars, double and multiple ; Stars, nearby ; Exoplanets ;
Stars, distances ; Stars, diameters ; Proper motions
Keywords: Exoplanets - Exoplanet formation - Binary stars - Close binary stars -
Speckle interferometry
Abstract:
The Transiting Exoplanet Survey Satellite (TESS) is finding transiting
planet candidates around bright, nearby stars across the entire sky.
The large field of view, however, results in low spatial resolution;
therefore, multiple stars contribute to almost every TESS light curve.
High angular resolution imaging can detect the previously unknown
companions to planetary candidate hosts that dilute the transit depths,
lead to host star ambiguity, and, in some cases, are the source of
false-positive transit signals. We use speckle imaging on the Southern
Astrophysical Research (SOAR) telescope to search for companions to 542
TESS planet candidate hosts in the southern sky. We provide correction
factors for the 117 systems with resolved companions due to photometric
contamination. The contamination in TESS due to close binaries is similar
to that found in surveys of Kepler planet candidates. For the solar-type
population, we find a deep deficit of close binary systems with projected
stellar separations less than 100 au among planet candidate hosts (44
observed binaries compared to 124 expected based on field binary
statistics). The close binary suppression among TESS planet candidate
hosts is similar to that seen for the more distant Kepler population.
We also find a large surplus of TESS planet candidates in wide binary
systems detected in both SOAR and Gaia DR2 (Cat. I/345) (119 observed
binaries compared to 77 expected). These wide binaries almost exclusively
host giant planets, however, suggesting that orbital migration caused
by perturbations from the stellar companion may lead to planet-planet
scattering and suppress the population of small planets in wide binaries.
Both trends are also apparent in the M dwarf planet candidate hosts.
Description:
542 TESS planet candidate hosts were observed with the high-resolution
camera (HRCam) imager on the 4.1 m SOAR telescope over 7 nights in
2018-2019. The observation procedure and data reduction are described
in Tokovinin (2018PASP..130c5002T 2018PASP..130c5002T). Briefly, each observation consists
of 400 frames split into two data cubes, typically consisting of a
200x200 binned pixels region of interest centered on the target star
(6.3" on a side at the pixel scale of 0.01575" and 2x2 binning) taken
in approximately 11 s with an Andor iXon-888 camera.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table6.dat 96 590 Full SOAR speckle observation list and binary
properties
table1.dat 61 130 Nearby stars detected by SOAR to TESS planet
candidate hosts
table2.dat 58 30 TIC matches to resolved binaries detected
by SOAR
table3.dat 48 368 Detection bias of TESS planets in multiple stars
table4.dat 88 38 Gaia DR2 matches to resolved binaries detected
by SOAR
table5.dat 96 53 Gaia DR2 binaries to TESS targets not detected
by SOAR
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See also:
B/wds : The Washington Visual Double Star Catalog (Mason+, 2014)
I/345 : Gaia DR2 (Gaia, 2018)
I/347 : Distances to 1.33 billion stars in Gaia DR2 (Bailer-Jones+, 2018)
IV/38 : TESS Input Catalog - v8.0 (TIC-8) (Stassun+, 2019)
J/ApJ/809/77 : Transiting Exoplanet Survey Satellite (TESS) (Sullivan+, 2015)
J/AJ/156/102 : The TESS Input Catalog and Candidate Target List
(Stassun+, 2018)
J/AJ/158/243 : A search for multiplanet systems with TESS (Pearson, 2019)
Byte-by-byte Description of file: table6.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 4 I4 --- TOI [0/1049] TESS Object of Interest identifier (1)
6- 14 I9 --- TIC [1003831/462162948] TESS Input Catalog identifier
16- 20 A5 --- Comp Components of resolved binary (2)
22- 30 F9.5 deg RAdeg Right Ascension in decimal degrees (J2000)
32- 40 F9.5 deg DEdeg Declination in decimal degrees (J2000)
42 A1 --- Filt [VIy] Filter used
44- 52 F9.4 yr Year [2018.255/2019.619] Julian year of the
observation
54- 58 F5.1 deg theta [0/352.4]? Position angle θ (3)
60- 63 F4.1 mas tanrho [0/27.4]? Tangential direction uncertainty in rho
ρσθ (3)
65- 69 F5.3 arcsec rho [0/4.075]? Separation ρ (3)
71- 74 F4.1 mas radrho [0.1/27.4]? Radial direction uncertainty in rho
σρ (3)
76- 78 F3.1 mag Dmag [0/7.1]? Measured magnitude difference (3)
80 A1 --- Flag Photometry flag (4)
82- 86 F5.3 arcsec minrho [0.033/0.126] Estimated resolution limit
88- 91 F4.2 mag Dm0.15 [0/3.22] Estimated maximum detectable Dmag
at 0.15" separation
93- 96 F4.2 mag Dm1.0 [0/5.67] Estimated maximum detectable Dmag
at 1.0" separation
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Note (1): This is zero for community TOIs.
Note (2): According to the WDS style (mostly "AB"). This matters for resolved
triple systems, indicating their hierarchy.
Note (3): These values are blank for unresolved sources (single stars).
Note (4): Flag as follows:
: = A companion with a low signal-to-noise ratio;
q = An identified quadrant from the shift-and-add images;
* = The photometry is corrected for anisoplanatism using the average image.
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Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 4 I4 --- TOI [123/1049] TESS Object of Interest identifier
6- 11 F6.4 arcsec Sep [0.031/4.0745] Separation
13- 17 F5.1 deg PA [0.3/352.5] Position angle
19- 21 F3.1 mag Cont [0/6.6] I-band contrast
23- 26 I4 K Teff [3562/9488]? Effective temperature
28- 31 I4 pc Dist [20/1330]? Distance to the TOI given in the TIC
(Stassun et al. 2019, Cat. IV/38)
33- 36 I4 AU PSep [3/2338]? Projected separation of the companion (1)
38- 42 F5.3 --- RCF1 [1.001/1.414] Radius correction factor (2)
44- 49 F6.3 --- RCF2 [1.338/19.856]? Radius correction factor (3)
51 I1 --- Det [1/3] Flag denoting a previous detection (4)
53- 61 A9 --- Disc Discoverer designation code (5)
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Note (1): Derived from the on-sky separation measured by SOAR and the distance
to the star.
Note (2): Radius correction factor for hosted planets in each system due to the
contamination from the detected star in the scenarios in which the primary is
the planetary host.
Note (3): Radius correction factor for hosted planets in each system due to the
contamination from the detected star in the scenarios in which the physically
associated secondary is the planetary host.
Note (4): Flag as follows:
1 = New pair, contamination not included in the TIC;
2 = Known pair, contamination not included in the TIC;
3 = Known pair, contamination included in the TIC.
Note (5): If the companion is in the Washington Double Star Catalog (Cat. B/wds)
maintained by the USNO. Explanations for codes are available at
http://www.usno.navy.mil/USNO/astrometry/optical-IR-prod/wds/WDS.
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 3 I3 --- TOI [123/907] TESS Object of Interest identifier
5- 13 I9 --- TIC1 [40083958/460205581] TESS Input Catalog identifier
for the primary star
15- 24 I10 --- TIC2 [48476907/2052060639] TESS Input Catalog
identifier for the secondary star
26- 31 F6.4 arcsec Sep-S [0.1593/4.0745] Separation from the SOAR
observations
33- 37 F5.1 deg PA-S [45.3/351.2] Position angle from the SOAR
observations
39- 41 F3.1 mag Cont-S [0.1/5.9] I-band contrast from the SOAR
observations
43- 46 F4.2 arcsec Sep-T [0.39/4.07] Separation derived from the TIC
coordinates
48- 52 F5.1 deg PA-T [39.3/353.9] Position angle derived from the TIC
coordinates
54- 58 F5.2 mag Cont-T [-0.71/6.21] TESS band contrast
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 4 I4 --- TOI [101/1024] TESS Object of Interest identifier
6- 11 F6.2 d Per [0.25/183.46] Orbital period (1)
13- 17 F5.2 Rgeo Rp [0.85/44.01] Planetary radius (1)
19- 22 F4.2 Rsun R* [0.19/7.68] Stellar radius from TIC
24- 28 F5.2 h Dur [0.4/32.15] Transit duration
30- 34 I5 ppm Depth [112/82635] Transit depth
36- 41 F6.1 ppm CDPP [25.7/1262.9] Effective combined differential
photometric precision (2)
43 I1 --- Nsec [1/9] Number of TESS sections target was observed
45- 48 F4.2 --- alpha [0.57/1] Correction factor α (3)
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Note (1): Of the planet with the highest signal-to-noise ratio.
Note (2): Of Stassun et al. (2019AJ....158..138S 2019AJ....158..138S) and interpolated to the
duration of the transit.
Note (3): For the bias against planet detection in binary stars. The factor
ranges from zero to one, with one indicating 100% detection rate even with
the flux contamination from a companion star.
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Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 3 I3 --- TOI [123/907] TESS Object of Interest identifier
5- 13 I9 --- TIC [9858404/460205581] TESS Input Catalog identifier
15- 33 I19 --- Source1 Gaia DR2 source ID for the primary star
35- 53 I19 --- Source2 Gaia DR2 source ID for the secondary star
55- 60 F6.4 arcsec Sep-S [1.117/4.0745] Separation from the SOAR
observations
62- 66 F5.1 deg PA-S [45.3/351.2] Position angle from the SOAR
observations
68- 70 F3.1 mag Cont-S [0.1/5.9] I-band contrast from the SOAR
observations
72- 76 F5.3 arcsec Sep-G [1.112/4.068] Separation derived from the Gaia
DR2 coordinates
78- 83 F6.2 deg PA-G [45.24/351.78] Position angle derived from
the Gaia DR2 coordinates
85- 88 F4.2 mag Cont-G [0.1/6.13] Gaia G-band contrast
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Byte-by-byte Description of file: table5.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 3 I3 --- TOI [129/938] TESS Object of Interest identifier
5- 13 I9 --- TIC [7624182/439456714] TESS Input Catalog identifier
15- 33 I19 --- Source1 Gaia DR2 source ID for the primary star
35- 53 I19 --- Source2 Gaia DR2 source ID for the secondary star
55- 59 F5.1 pc Dist1 [32/789.3] Distance from the primary star from
Bailer-Jones et al. (2018, Cat. I/347)
61- 65 F5.1 pc Dist2 [30.9/814.6] Distance from the secondary star
from Bailer-Jones et al. (2018, Cat. I/347)
67- 71 F5.1 mas/yr pm1 [5.1/273.5] Proper motion in Gaia DR2 for
the primary star
73- 77 F5.1 mas/yr pm2 [3.3/274.6] Proper motion in Gaia DR2 for
the secondary star
79- 83 F5.2 arcsec Sep [2.25/17.25] On-sky separation based on the Gaia
DR2 coordinates
85- 90 F6.1 AU PSep [129.6/4882.2] Projected physical separation
using the average of the distances to the two
stars
92- 96 F5.2 mag Cont [0.28/10.99] Gaia G-band contrast of the stellar
pair
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History:
From electronic version of the journal
(End) Prepared by [AAS], Tiphaine Pouvreau [CDS] 26-Feb-2020