J/AJ/156/140 Four new eclipsing mid M-dwarf systems from MEarth (Irwin+, 2018)
Four new eclipsing mid M-dwarf systems from the new Luyten two tenths catalog.
Irwin J.M., Charbonneau D., Esquerdo G.A., Latham D.W., Winters J.G.,
Dittmann J.A., Newton E.R., Berta-Thompson Z.K., Berlind P., Calkins M.L.
<Astron. J., 156, 140 (2018)>
=2018AJ....156..140I 2018AJ....156..140I (SIMBAD/NED BibCode)
ADC_Keywords: Stars, double and multiple ; Binaries, eclipsing ; Stars, dwarfs ;
Stars, M-type ; Stars, brown dwarf ; Proper motions ;
Photometry, G band ; Photometry, infrared ; Radial velocities
Keywords: binaries: eclipsing - brown dwarfs - stars: low-mass
Abstract:
Using data from the MEarth-North and MEarth-South transit surveys, we
present the detection of eclipses in four mid M-dwarf systems: LP 107-25,
LP 261-75, LP 796-24, and LP 991-15. Combining the MEarth photometry with
spectroscopic follow-up observations, we show that LP 107-25 and LP 796-24
are short-period (1.388 and 0.523 day, respectively) eclipsing binaries
in triple-lined systems with substantial third-light contamination from
distant companions. LP 261-75 is a short-period (1.882 day) single-lined
system consisting of a mid M-dwarf eclipsed by a probable brown dwarf
secondary, with another distant visual brown dwarf companion. LP 991-15
is a long-period (29.3 day) double-lined eclipsing binary on an eccentric
orbit with a geometry that produces only primary eclipses. A spectroscopic
orbit is given for LP 991-15, and initial orbits for LP 107-25 and
LP 261-75.
Description:
We operate the MEarth project, an all-sky survey using two robotic
telescope arrays to search for transiting planets orbiting fully
convective M-dwarfs within 33 pc by obtaining high-cadence differential
photometry (Nutzman & Charbonneau 2008PASP..120..317N 2008PASP..120..317N). This survey is
also highly sensitive to eclipsing binaries, which present much larger
photometric signals than transiting planets, and has been optimized
for efficient recovery of objects with long orbital periods. Target
selection for MEarth-North is described in detail in Nutzman & Charbonneau
(2008PASP..120..317N 2008PASP..120..317N), and for MEarth-South in Irwin et al.
(2015csss...18..767I 2015csss...18..767I). All four targets presented here were selected
for observation based on photometric distance estimates placing them
within 33 pc, a volume limit inherited from the work of Lepine (2005,
J/AJ/130/1680), upon which our original target selection was based.
The MEarth data themselves, data reduction, and analysis methods have
been described in detail in previous papers (Irwin et al.
2011ApJ...727...56I 2011ApJ...727...56I, 2011, J/ApJ/742/123; Berta et al. 2012AJ....144..145B 2012AJ....144..145B;
Newton et al. 2016, J/ApJ/821/93). The objects presented here were detected
during the 2011-2017 observing seasons, during which time the configuration
of both instruments was relatively stable, with all observations taken
using the same RG715 filter bandpass.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 189 4 Summary of the photometric and astrometric
properties of the four systems
table2.dat 156 28452 Light curve data
table4.dat 58 45 Radial velocity data
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See also:
I/98 : NLTT Catalogue (Luyten, 1979)
VII/233 : The 2MASS Extended sources (IPAC/UMass, 2003-2006)
I/298 : LSPM-North Catalog (Lepine+ 2005)
I/339 : Hot Stuff for One Year (HSOY) (Altmann+, 2017)
I/345 : Gaia DR2 (Gaia Collaboration, 2018)
J/AJ/126/3007 : Spectroscopy of faint red NLTT dwarfs (Reid+, 2003)
J/AJ/130/1680 : LSPM-North proper-motion catalog nearby stars (Lepine+, 2005)
J/ApJ/699/649 : Young M dwarfs within 25pc. I. (Shkolnik+, 2009)
J/ApJ/742/123 : Photometry and Velocity of LSPM J1112+7626 (Irwin+, 2011)
J/ApJ/812/3 : MEarth mid-to-late M dwarfs rotation + kinematics (West+, 2015)
J/ApJ/818/153 : MEarth photometry: nearby M-dwarf magnitudes (Dittmann+, 2016)
J/ApJ/821/93 : Rotation & Galactic kinematics of mid M dwarfs (Newton+, 2016)
Byte-by-byte Description of file: table1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 8 A8 --- Name Object identifier from the NLTT catalog
(Cat. I/98, LPNNN-NN)
10- 26 A17 --- 2MASS 2MASS identifier (JHHMMSSss-DDMMSSs)
28- 29 I2 h RAh Hour of Right Ascension (J2000)
31- 32 I2 min RAm Minute of Right Ascension (J2000)
34- 38 F5.2 s RAs Second of Right Ascension (J2000)
40 A1 --- DE- Sign of the Declination (J2000)
41- 42 I2 deg DEd Degree of Declination (J2000)
44- 45 I2 arcmin DEm Arcminute of Declination (J2000)
47- 50 F4.1 arcsec DEs Arcsecond of Declination (J2000)
52- 63 F12.9 d Per [0.523438/29.2679] Orbital period (from
Table 3 of this paper)
65- 75 F11.9 d e_Per [1.4e-08/8.1e-06] Uncertainty in Per (from
Table 3 of this paper)
77- 82 F6.3 arcsec/yr pmRA [-0.292/0.243] Proper motion along RA
84- 88 F5.3 arcsec/yr e_pmRA [0.002/0.008]? Uncertainty in pmRA
90- 95 F6.3 arcsec/yr pmDE [-0.171/0.189] Proper motion along DE
97-101 F5.3 arcsec/yr e_pmDE [0.002/0.008]? Uncertainty in pmDE
103 I1 --- Source1 [1/6] Source reference (1)
105-112 F8.6 arcsec Plx [0.021033/0.031633] Astrometric parallax
πtrig
114-121 F8.6 arcsec e_Plx [6.4e-05/0.00014] Uncertainty in Plx
123-128 F6.3 mag Gmag [12.749/13.98] Gaia G band magnitude
130-135 F6.3 mag BPmag [14.163/15.84] Gaia GBP magnitude
137-142 F6.3 mag RPmag [11.586/12.692] Gaia GRP magnitude
144 I1 --- Source2 [3] Source reference (1)
146-151 F6.3 mag Jmag [9.988/10.814] 2MASS J band magnitude
153-157 F5.3 mag e_Jmag [0.021/0.026] Uncertainty in Jmag
159-164 F6.3 mag Hmag [9.406/10.205] 2MASS H band magnitude
166-170 F5.3 mag e_Hmag [0.019/0.028] Uncertainty in Hmag
172-176 F5.3 mag Ksmag [9.164/9.918] 2MASS Ks band magnitude
178-182 F5.3 mag e_Ksmag [0.019/0.023] Uncertainty in Ksmag
184-187 A4 --- SpType MK spectral type
189 I1 --- Source3 [4/5]? Source reference (1)
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Note (1): Source as follows:
1 = Lepine & Shara (2005, Cat. I/298);
2 = Altmann et al. (2017, Cat. I/339);
3 = Gaia Collaboration (2018, Cat. I/345);
4 = Reid & Walkowicz (2006PASP..118..671R 2006PASP..118..671R);
5 = Reid et al. (2003, J/AJ/126/3007);
6 = 2MASS (Skrutskie et al. 2006, VII/233)/NLTT (Luyten, 1979, Cat. I/98).
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Byte-by-byte Description of file: table2.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 8 A8 -- Name Object identifier from the NLTT catalog
(Cat. I/98, LPNNN-NN)
10- 27 A18 -- Dataset Dataset name; telescope / observation
29- 42 F14.6 d BJD Barycentric Julian Date at mid-exposure
44- 52 F9.6 mag Dmag [-0.43185/0.225121] Differential magnitude
54- 61 F8.6 mag e_Dmag [0.001806/0.011568] Uncertainty in Dmag
63- 68 F6.3 s Texp [32.031/60.037] Exposure time
70- 76 F7.4 mag DMag [-0.7505/0.1183] Frame magnitude zero point
offset
78- 82 F5.3 pix FWHM [0/7.387] FWHM of stellar images
84- 88 F5.3 -- Ellip [0.005/0.481] Ellipticity of stellar images
90- 96 F7.5 -- Airmass [1.00268/2.91807] Airmass at mid-exposure
98-105 F8.3 pix Xpix [242.44/1760.169] X pixel coordinate of star
107-114 F8.3 pix Ypix [24.392/2014.681] Y pixel coordinate of star
116-122 F7.2 deg Angle [-180/180] Angle relative to reference image
124-130 F7.2 --- Sky [32.21/9270.42] Local sky background level
(in ADU)
132-136 I5 --- Peak [477/22795] Peak counts in object, including
sky (in ADU)
138-139 I2 -- S [1/10] The "Segment number" (1)
141-142 I2 -- V [1/13] The "Instrument version number" (2)
144 I1 -- R [0/2] Realtime status flag (3)
146 I1 -- F [0] Flags (4)
148-156 F9.6 mag CM [-0.012045/0.012568] Common-mode differential
magnitude (5)
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Note (1): Integer identifying points of the light curve sharing a common
magnitude zero point offset.
Note (2): Integer incremented by 1 each time the detector is removed and
replaced on the telescope.
Note (3): Non-zero if the data point was taken in response to a real-time
trigger. Values are 1 or 2, corresponding to two stages of the real-time
detection process: confirmation (R=1), or high-cadence followup (R=2).
Note (4): The following values are used, combined with a bitwise OR operation:
2 = Aperture contains known bad pixels;
4 = Possible saturation detected.
Note (5): Gives the "common mode" interpolated to the Julian date of the
exposure. Derived from the average differential magnitude of all the M-dwarfs
observed by all 8 telescopes at the same site in a given time interval. This
should be scaled and subtracted from "mag" to correct for variations in
precipitable water vapor.
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Byte-by-byte Description of file: table4.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 8 A8 --- Name Object identifier from the NLTT catalog
(Cat. I/98, LPNNN-NN) (1)
10- 21 F12.4 d BJD Barycentric Julian Date (TDB)
23- 29 F7.3 km/s RV1 [-43.197/38.591] Radial velocity of the primary
31- 38 F8.3 km/s RV2 [-124.2/103.919]? Radial velocity of the secondary
40- 46 F7.3 km/s RV3 [-22.153/-9.361]? Radial velocity of the tertiary
48- 53 F6.4 --- h [0.8233/0.9435] Cross-correlation at the
best-fitting radial velocity
55- 58 I4 s Texp [2700/3900] Exposure time
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Note (1): Additional data on objects:
LP107-25: α=0.0748, β=0.2048; vb1=15.5 km/s, vb2=6.7 km/s;
LP261-75: vb1=7.57 km/s;
LP991-15: α=0.6510.
α and β are spectroscopic light ratio parameters; vbj is
rotational broadening applied to star j.
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History:
From electronic version of the journal
(End) Prepared by [AAS], Tiphaine Pouvreau [CDS] 08-Mar-2019