J/AJ/165/6 BD+37 410 & DS And light curve and radial velocity (Sandquist+, 2023)
Evolved Eclipsing Binaries and the Age of the Open Cluster NGC 752.
Sandquist E.L., Buckner A.J., Shetrone M.D., Barden S.C.,
Pilachowski C.A., Deliyannis C.P., Harmer D., Mathieu R., Meibom S.,
Frandsen S.,Orosz J.A.
<Astron. J., 165, 6 (2023)>
=2023AJ....165....6S 2023AJ....165....6S
ADC_Keywords: Clusters, open; Stars, double and multiple; Spectra, optical;
Photometry, UBVRIJKLMNH; Radial velocities
Keywords: Eclipsing binary stars ; Spectroscopic binary stars ; Open
star clusters ; Low mass stars ; Stellar ages ; Stellar
physics
Abstract:
We present analyses of improved photometric and spectroscopic
observations for two detached eclipsing binaries at the turnoff of the
open cluster NGC752: the 1.01days binary DSAnd and the 15.53days
BD+37410. For DSAnd, we find M1=1.692±0.004±0.010M☉,
R1=2.185±0.004±0.008R☉, M2=1.184
±0.001±0.003M☉, and R2=1.200±0.003±0.005R☉. We
either confirm or newly identify unusual characteristics of both stars
in the binary: the primary star is found to be slightly hotter than
the main-sequence turnoff and there is a more substantial discrepancy
in its luminosity compared to models (model luminosities are too large
by about 40%), while the secondary star is oversized and cooler
compared to other main-sequence stars in the same cluster. The
evidence points to nonstandard evolution for both stars, but most
plausible paths cannot explain the low luminosity of the primary star.
BD+37410 only has one eclipse per cycle, but extensive spectroscopic
observations and the Transiting Exoplanet Survey Satellite light curve
constrain the stellar masses well: M1=1.717±0.011M☉ and
M2=1.175±0.005M☉. The radius of the main-sequence primary star
near 2.9R☉ definitively requires large convective core
overshooting (>0.2 pressure scale heights) in models for its mass, and
multiple lines of evidence point toward an age of
1.61±0.03±0.05Gyr (statistical and systematic uncertainties).
Because NGC752 is currently undergoing the transition from
nondegenerate to degenerate He ignition of its red clump stars,
BD+37410A directly constrains the star mass where this transition
occurs.
Description:
We made primary use of photometry from the Transiting Exoplanet Survey
Satellite (TESS) taken in sector 18 of the northern hemisphere
campaign.
Our ground-based photometric observations of DS And were taken with
the 1m telescope at Mount Laguna Observatory with the CCD 2005
camera. This camera uses a 2048x2048 CCD with a field of view
approximately 13.5' on a side. Observations were taken during the course
of one season in 2010 with the intention of fully covering eclipse
phases in BVRCIC filters, along with sparser coverage of
out-of-eclipse phases.
We took additional observations at the 1m telescope in U during 2020
in order to constrain the spectral energy distribution for the
component stars.
Finally, we used light curves from the Wide Field Infrared Explorer
(WISE) in the W1 and W2 bandpasses.
For DS And, we obtained 17 spectra at the Hobby-Eberly Telescope (HET)
with the High Resolution Spectrograph (HRS) between 2010 August and
2011 September. Exposure times ranged from 1260 to 12240s, and we only
used the wavelength range 4825-5760Å (R=30000). We also reanalyzed
15 observations of DS And taken using the Fiber-fed Echelle
Spectrograph (FIES) on the 2.56m Nordic Optical Telescope (NOT) in
2007 August, and 2008 July-November.
For BD +37 410, our primary source for velocity measurements was
previously unpublished spectra taken with Hydra multifiber echelle
spectrograph on the 3.5m WIYN telescope at Kitt Peak National
Observatory between 2001 August 18 and 2009 September 30. The spectra
covered 4990-5250Å near the MgI b triplet. Typically, 8-10
exposures of around 1800s were taken each night of observations, and
had high signal-to-noise ratios. After some experimentation, we
settled on the 4990-5177Å range for our analysis as this appeared
to provide the best signal on the fainter secondary star.
Objects:
------------------------------------------------------------
RA (2000) DE Designation(s) (Period)
------------------------------------------------------------
01 56 53.52 +37 47 38.4 NGC 752 = C 0154+374
01 57 46.05 +38 04 28.4 DS And = V* DS And (P=1.01d)
01 55 29.29 +37 50 26.3 BD+37 410 = BD+37 410 (P=15.53d)
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File Summary:
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FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table3.dat 32 6733 Time-series photometry used in modeling DS And
table9.dat 69 198 Radial velocity measurements
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See also:
II/215 : uvby-beta Catalogue (Hauck+ 1997)
I/259 : The Tycho-2 Catalogue (Hog+ 2000)
II/287 : Northern Sky Variability Survey (NSVS) (Wozniak+, 2004)
II/271 : TASS Mark IV patches photometric catalog, version 2 (Droege+, 2007)
IV/38 : TESS Input Catalog - v8.0 (TIC-8) (Stassun+, 2019)
I/352 : Distances to 1.47 billion stars in Gaia EDR3 (Bailer-Jones+, 2021)
VI/120 : High-resolution synthetic stellar library (Coelho+, 2005)
VII/233 : The 2MASS Extended sources (IPAC/UMass, 2003-2006)
V/152 : The DEBCat detached eclipsing binary catalogue (Southworth, 2015)
VI/96 : Evolutionary Sequences (Fagotto+ 1993-96)
J/PASP/106/281 : Photometry and radial velocities in NGC752 (Daniel+, 1994)
J/A+A/324/137 : Eclipsing binaries with candidate CP stars (North+ 1997)
J/A+A/333/231 : O-M stars model atmospheres (Bessell+ 1998)
J/A+A/339/423 : Velocities of red giants in NGC 752 (Mermilliod+ 1998)
J/AJ/128/1319 : New AY Cam Photometric Observations (Williamon+, 2004)
J/ApJ/640/1018 : Differential photometry of V1061 Cyg (Torres+, 2006)
J/ApJS/176/262 : VRI photometry & theta values in open clusters (Taylor+, 2008)
J/A+A/502/253 : V636 Cen radial velocities curves (Clausen+, 2009)
J/A+A/498/949 : Velocities 1253 F-K dwarfs open clusters (Mermilliod+, 2009)
J/A+A/512/A54 : Teff and Fbol from Infrared Flux Method (Casagrande+, 2010)
J/other/A+ARV/18.67 : Accurate masses and radii of normal stars (Torres+, 2010)
J/BaltA/19/35 : NGC 752 Vilnius photometry (Zdanavicius+, 2010)
J/A+A/535/A30 : Chemical abundance 12 stars in open clusters (Carrera+, 2011)
J/A+A/535/A3 : SuperWASP observations of pulsating Am stars (Smalley+, 2011)
J/MNRAS/419/1350 : Red giants abundances in 4 open clusters (Reddy+, 2012)
J/A+A/537/A117 : Velocity curves of SW CMa and HW CMa (Torres+, 2012)
J/A+A/552/A16 : Limb-darkening for CoRoT, Kepler, Spitzer. II. (Claret+, 2013)
J/MNRAS/446/3562 : Abundances of red giants in NGC752 (Bocek Topcu+, 2015)
J/AJ/150/154 : Photometry and spectroscopy of V501 Mon (Torres+, 2015)
J/AJ/150/134 : uvbyCaHβ photometry of NGC 752 (Twarog+, 2015)
J/ApJ/831/11 : KIC9777062 RVs & asteroseismology NGC6811 (Sandquist+, 2016)
J/ApJ/838/25 : Hectochelle spectroscopy for 776 Kepler stars (Guo+, 2017)
J/ApJ/862/33 : Improved & expanded membership cat. NGC752 (Agueros+, 2018)
J/A+A/618/A93 : Gaia DR2 open clusters in the Milky Way (Cantat-Gaudin+, 2018)
J/ApJS/237/28 : WISE catalog of periodic variable stars (Chen+, 2018)
J/A+A/618/A20 : Limb-darkening for TESS, Kepler, Corot, MOST (Claret, 2018)
J/A+A/616/A10 : 46 open clusters GaiaDR2 HR diagram (Gaia Collaboration, 2018)
J/AJ/156/102 : TESS Input Catalog and Candidate Target List (Stassun+, 2018)
J/AJ/158/163 : Li abundance values for stars in NGC 6819 (Deliyannis+, 2019)
J/ApJ/878/99 : Abundances of dwarfs & giants NGC752 with HIRES (Lum+, 2019)
J/AJ/158/82 : DS Andromedae radial velocity & photometry (Milone+, 2019)
J/AJ/158/35 : Swift UVOT Stars III. Galactic open clusters (Siegel+, 2019)
J/ApJS/249/22 : Radial velocity variable stars from LAMOST DR4 (Tian+, 2020)
Byte-by-byte Description of file: table3.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 12 F12.6 --- BJD [39748/59099] Barycentric Julian Date, BJD-2400000.0
14- 17 A4 --- Filt Filter used; B, Ic, Rc, TESS, U, V, W1 or W2
19- 25 F7.4 mag omag [-0.11/12.4] Observed magnitude in Filter
27- 32 F6.4 mag e_omag [0.003/0.07] Uncertainty in omag
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Byte-by-byte Description of file: table9.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1-10 A10 --- Star Star name; BD+37 140 or DS And
12-19 A8 --- Obs Observatory (1)
21-31 F11.5 d BJD [44165/56587] Barycentric Julian Date, BJD-2400000.0
33-33 A1 --- Flag [b] Fit flag, b=not used in fit
35-41 F7.2 km/s RVelA [-119/129]? Component A radial velocity
43-46 F4.2 km/s e_RVelA [0.04/5]? Uncertainty in RVel-A
48-54 F7.2 km/s RVelB [-174/183]? Component B radial velocity
56-59 F4.2 km/s e_RVelB [0.1/4]? Uncertainty in RVel-B
61-64 F4.2 km/s RVelC [3.48/7.96]? Component C radial velocity
66-69 F4.2 km/s e_RVelC [0.1/0.5]? Uncertainty in RVel-C
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Note (1): Observatories as follows:
CORAVEL = photoelectric scanner CORAVEL on the Swiss 1m telescope at
Observatoire de Haute-Provence
CfA = CfA Digital Speedometers
DDO = Slit spectrograph on the 1.88m telescope of the David Dunlop
Observatory
HET HRS = Hobby-Eberly Telescope High Resolution Spectrograph
LAMOST = LAMOST Data Release 4
NOT FIES = Nordic Optical Telescope, FIbre-fed Echelle Spectrograph
WIYN = HYDRA on the 3.5m WIYN telescope at Kitt Peak National
Observatory
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History:
From electronic version of the journal
(End) Prepared by [AAS], Coralie Fix [CDS], 10-Mar-2023