J/AJ/162/75 Speckle observations TESS exoplanet host stars. II. (Lester+, 2021)
Speckle observations of TESS exoplanet host stars.
II. Stellar companions at 1-1000au and implications for small planet detection.
Lester K.V., Matson R.A., Howell S.B., Furlan E., Gnilka C.L., Scott N.J.,
Ciardi D.R., Everett M.E., Hartman Z.D., Hirsch L.A.
<Astron. J., 162, 75-75 (2021)>
=2021AJ....162...75L 2021AJ....162...75L (SIMBAD/NED BibCode)
ADC_Keywords: Exoplanets; Stars, double and multiple; Photometry, VRI;
Interferometry; Effective temperatures
Keywords: Speckle interferometry; High angular resolution; Exoplanets
Binary stars
Abstract:
We present high-angular-resolution imaging observations of 517 host
stars of TESS exoplanet candidates using the 'Alopeke and Zorro
speckle cameras at Gemini North and South. The sample consists mainly
of bright F, G, K stars at distances of less than 500pc. Our speckle
observations span angular resolutions of ∼20mas out to 1.2", yielding
spatial resolutions of <10-500au for most stars, and our contrast
limits can detect companion stars 5-9mag fainter than the primary at
optical wavelengths. We detect 102 close stellar companions and
determine the separation, magnitude difference, mass ratio, and
estimated orbital period for each system. Our observations of
exoplanet host star binaries reveal that they have wider separations
than field binaries, with a mean orbital semimajor axis near 100 au.
Other imaging studies have suggested this dearth of very closely
separated binaries in systems which host exoplanets, but
incompleteness at small separations makes it difficult to disentangle
unobserved companions from a true lack of companions. With our
improved angular resolution and sensitivity, we confirm that this lack
of close exoplanet host binaries is indeed real. We also search for a
correlation between planetary orbital radii versus binary star
separation; but, given the very short orbital periods of the TESS
planets, we do not find any clear trend. We do note that in exoplanet
systems containing binary host stars, there is an observational bias
against detecting Earth-size planet transits due to transit depth
dilution caused by the companion star.
Description:
We observed 517 stars from the Transiting Exoplanet Survey Satellite
(TESS) Objects of Interest (TOI) catalog using the 'Alopeke and Zorro
speckle cameras' on the Gemini 8.1m North and South telescopes,
respectively, from 2019 May-2020 December. At least three image sets
were obtained for each target, where one set consists of 1000 60ms
exposures taken in a 562nm and an 832nm filter simultaneously.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 105 581 Gemini observing log
table2.dat 63 102 Companions detected
table3.dat 36 59 Corrected radii of planet candidates in close
binary systems
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See also:
I/337 : Gaia DR1 (Gaia Collaboration, 2016)
IV/34 : K2 Ecliptic Plane Input Catalog (EPIC) (Huber+, 2017)
IV/38 : TESS Input Catalog - v8.0 (TIC-8) (Stassun+, 2019)
J/ApJS/190/1 : A survey of stellar families (Raghavan+, 2010)
J/AJ/141/45 : Speckle observations of HIP stars (Horch+, 2011)
J/AJ/142/19 : Speckle observations of KOI (Howell+, 2011)
J/ApJ/745/19 : Binary systems in Taurus-Auriga (Kraus+, 2012)
J/ApJS/208/9 : Intrinsic colors and temperatures of PMS stars (Pecaut+, 2013)
J/AJ/152/8 : Impact of stellar multip. on planetary systems I. (Kraus+, 2016)
J/AJ/153/71 : Kepler follow-up observation program. I. Imaging (Furlan+, 2017)
J/AJ/156/18 : APOGEE DR14:Binary comp. of evolved stars (Price-Whelan+, 2018)
J/AJ/156/102 : The TESS Input Catalog & Candidate Target List (Stassun+, 2018)
J/AJ/157/211 : Unresolved binaries in TESS with speckle imaging (Matson+, 2019)
J/AJ/157/216 : Stellar multiplicity rate M dwarfs within 25pc (Winters+, 2019)
J/AJ/158/113 : Kepler-13AB aperture photometry (Howell+, 2019)
J/AJ/159/19 : SOAR TESS survey. I. (Ziegler+, 2020)
J/AN/341/996 : Stellar companions of (C)TOIs (Mugrauer+, 2020)
J/AJ/161/21 : 383 KOIs interferometry with WIYN (Colton+, 2021)
J/AJ/161/134 : Survey of stellar & planetary comp. within 25pc (Hirsch+, 2021)
J/AJ/161/164 : Observation of 186 TESS stars with NESSI (WYIN) (Howell+, 2021)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 4 I4 --- TOI TESS Target of Interest identifier
6- 14 I9 --- TIC TESS Input Catalog identifier (1)
16- 19 F4.1 mag Tmag [5.3/15.7] TESS magnitude
21- 26 F6.1 pc Dist [6.9/6814] Gaia EDR3 based distance (2)
28- 32 I5 K Teff [2808/31000] TIC effective temperature (1)
34- 34 A1 --- Tel Telescope; North or South
36- 37 I2 --- Obs.M Observation date, month (UT)
39- 40 I2 d Obs.D Observation date, day in month (UT)
42- 43 I2 yr Obs.Y [19/20] Observation date, year (UT)
45- 48 F4.2 mag mag0.2-562 [3.06/6.14] contrast limit at 0.2" and 562nm
50- 53 F4.2 mag mag1.0-562 [3.28/8.23] contrast limit at 1.0" and 562nm
55- 58 F4.2 mag mag0.2-832 [4.1/6.1] contrast limit at 0.2" and 832nm
60- 63 F4.2 mag mag1.0-832 [4.69/9.33] contrast limit at 1.0" and 832nm
65-105 A41 --- Notes Notes for each target (3)
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Note (1): TESS Input Catalog (TICv8.1); Stassun+, 2019, IV/38
Note (2): Inverse of the parallax from Gaia EDR3;
Gaia Collaboration+, 2016, I/337, and 2020arXiv201201533G 2020arXiv201201533G)
Note (3): Notes on targets include flags for false alarms, false positives,
other source names and ambiguous planetary candidates (APCs).
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 2 A2 --- Sample Target Sample (1)
4- 7 I4 --- TOI Target
9 A1 --- f_TOI *=Triple system; 6 occurrences (2)
11- 15 F5.3 arcsec rho1 [0.02/1.45]? Separation, arcseconds at 562nm
17- 21 F5.1 deg PA1 [19.5/348]? Position angle, degrees at 562nm
23- 26 F4.2 mag dmag1 [0.01/5.38]? Magnitude difference at 562nm
28- 32 F5.3 arcsec rho2 [0.02/1.73]? Separation, arcseconds at 832nm
34- 38 F5.1 deg PA2 [6.1/357]? Position angle, degrees at 832nm
40 A1 --- l_dmag2 Limit flag on dmag2
42- 45 F4.2 mag dmag2 [0.01/9.33]? Magnitude difference at 832nm
47- 50 F4.2 --- Q [0.14/1]? Mass ratio, Mcompanion/Mhost
52- 57 F6.1 au a [4.1/1122] Separation, projected
59- 63 I5 yr Per [6/23300] Binary period
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Note (1): Target as follows:
H = Exoplanet Host Stars; 73 occurrences
FP = Transit False Positive Stars ; 29 occurrences
Note (2): Source found to be in a triple system have parameters for each
companion listed sequentially in order of increasing separation.
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 4 I4 --- TOI Target name
6- 16 A11 --- Planet Planet candidate
18 A1 --- f_Planet Flag on Planet (1)
20- 24 F5.3 --- Corr [1/1.5]? Correction factor
26- 30 F5.2 Rgeo Rpl [1.66/32]? Apparent planetary radius
32- 36 F5.2 Rgeo Rpl-c [1.67/41]? Corrected planetary radius
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Note (1): The companion for these TOIs is listed as a nearby star in ExoFOP,
so its flux has already been accounted for when calculating the planet
radius.
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History:
From electronic version of the journal
References:
Howell et al. Paper I : 2021AJ....161..164H 2021AJ....161..164H Cat. J/AJ/161/164
(End) Prepared by [AAS], Coralie Fix [CDS], 23-Nov-2021