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J/ApJ/835/251  Radial velocities and BVIc LCs of the EB* CU Cnc  (Wilson+, 2017)

The M dwarf eclipsing binary CU Cancri. Wilson R.E., Pilachowski C.A., Terrell D. <Astrophys. J., 835, 251-251 (2017)> =2017ApJ...835..251W (SIMBAD/NED BibCode)
ADC_Keywords: Binaries, eclipsing ; Radial velocities ; Photometry, VRI Keywords: binaries: eclipsing; binaries: spectroscopic; stars: individual: CU Cnc Abstract: Spectral features, radial velocities, elemental abundance estimates, other spectral data, and BVIC light curves are reported for the double-M dwarf eclipsing binary CU Cancri-a good target for a radius check versus the Zero Age Main Sequence (ZAMS) due to the low component masses and corresponding very slow evolutionary expansion. The estimate of [Fe/H] is about 0.4, although continuum placement and other difficulties due to line crowding introduce the usual uncertainties for red dwarfs. Detection of the LiIλ6707 line was attempted, with an estimated upper limit of 50mÅ. Spectral and photometric indicators of stellar activity are described and illustrated. Other objectives were to measure the stellar radii via simultaneous velocity and light-curve solutions of earlier and new data while also improving the ephemeris by filling gaps in timewise coverage with the new velocities and eclipse data from the new light curves. The radii from our solutions agree within about 2% with those from Ribas, being slightly larger than expected for most estimates of the ZAMS. Some aspects of the red dwarf radius anomaly are briefly discussed. Evolution tracks show only very slight age-related expansion for masses near those in CU Cnc. Such expansion could be significant if CU Cnc were similar in age to the Galaxy, but then its Galactic velocity components should be representative of Population II, and they are not. Description: Infrared spectra of CU Cnc were obtained with the Phoenix spectrometer on the 2.1 and 4m telescopes at Kitt Peak National Observatory in 2013 December, and 2014 January and February (λc=2.33um, R=50000). The primary star is defined here as the slightly hotter and more massive one that is eclipsed near zero phase according to the ephemeris. High-resolution optical spectra of CU Cnc were obtained for estimation of elemental abundances. An 1800s observation was obtained on 2014 May 17 with the Astrophysical Research Consortium (ARC) echelle spectrograph (ARCES) at a phase near quadrature. A second spectrum was obtained with the same instrument on 2015 November 21 with an exposure time of 3600s at a phase near conjunction. The spectra cover the wavelength range from 3500 to 10000Å and resolving power is about 31500. The CU Cnc field was observed at the Sonoita Research Observatory with Johnson-Cousins BVIC and SDSS g'r'i' filters. Objects: ------------------------------------------------------------------------ RA (ICRS) DE Designation(s) (Period) ------------------------------------------------------------------------ 08 31 37.57 +19 23 39.4 V* CU Cnc = WDS J08317+1924A (P=2.771470) ------------------------------------------------------------------------ File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file table1.dat 38 48 Radial velocity observations with the Phoenix Spectrometer table3.dat 59 823 *Light curves in B, V , and IC bands
Note on table3.dat: CU Cnc aperture photometry was done in IRAF, with the BVIC differential magnitudes against GSC 1387-01006 extending from JD 2457006 to 2457081. See section 3 for further explanations.
See also: B/wds : The Washington Visual Double Star Catalog (Mason+ 2001-2014) J/A+A/337/403 : Low-mass stars evolutionary models (Baraffe+ 1998) J/A+A/398/239 : RI differential photometry of CU Cnc (Ribas, 2003) J/ApJ/628/411 : Identification & analysis of eclipsing binaries (Devor+, 2005) J/AJ/130/873 : Properties of BQS objects in the SDSS DR3 area (Jester+, 2005) J/MNRAS/406/2559 : BVRI light curves of GSC2314-0530 (Dimitrov+, 2010) J/ApJ/709/535 : Masses and radii of eclipsing binaries (Brown, 2010) J/ApJ/723/1469 : Flux calibrations and WZ Oph photometry (Wilson+, 2010) J/AJ/141/78 : Low-mass eclipsing binaries in KIC (Coughlin+, 2011) J/MNRAS/431/3240 : Ji photometry of WTS 19g-4-02069 (Nefs+, 2013) J/A+A/572/A50 : J0113+31 light + velocity curves (Gomez Maqueo Chew+, 2014) J/ApJ/789/102 : Properties of late M-dwarfs (Janson+, 2014) J/MNRAS/442/2620 : VRI light curve of 5 eclipsing binaries (Zhang+, 2014) J/MNRAS/437/2831 : 4 transiting F-M binary systems (Zhou+, 2014) J/other/PASA/31.24 : Milky Way detached double-lined EB catalog (Eker+, 2014) J/AJ/149/131 : Param. of galactic nearby main-sequence stars (Eker+, 2015) J/AJ/152/180 : Bolometric fluxes of EB* in Tycho-2 (Stassun+, 2016) Byte-by-byte Description of file: table1.dat
Bytes Format Units Label Explanations
1- 11 F11.5 d HJD Midpoint Heliocentric Julian date; HJD-2450000 13- 15 I3 s Exp [600/900] Integration time 17- 22 F6.2 km/s RV1 [-55/72] Radial velocity of the Primary 24- 29 F6.2 km/s RV2 [-71/68] Radial velocity of the Secondary 31- 34 F4.1 --- R [3/19] Tonry-Davis (1979AJ.....84.1511T) "R" value (1) 36- 38 F3.1 km/s sig [0.5/1.4]? Standard deviation of the four independent measurements
Note (1): The R value is the height of the cross-correlation peak divided by the noise in the cross-correlation function. Observations with R's above three are ordinarily considered reliable.
Byte-by-byte Description of file: table3.dat
Bytes Format Units Label Explanations
1- 12 F12.4 d HJD-B ?=0 Heliocentric Julian Date of B band observation 14- 19 F6.3 mag delBmag [-0.6/0.4]?=0 Differential B band magnitude 21- 32 F12.4 d HJD-V Heliocentric Julian Date of V band observation 34- 39 F6.3 mag delVmag [-0.9/-0.4] Differential V band magnitude 41- 52 F12.4 d HJD-Ic ?=0 Heliocentric Julian Date of Ic band observation 54- 59 F6.3 mag delIcmag [-2.8/-2.5]?=0 Differential Ic band magnitude
History: From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 01-Sep-2017
The document above follows the rules of the Standard Description for Astronomical Catalogues.From this documentation it is possible to generate f77 program to load files into arrays or line by line

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