J/AJ/166/29 Radial velocities, positions and photometry for 12 Com (Lam+, 2023)
Precise Age for the Binary Star System 12 Com in the Coma Berenices Cluster.
Lam R., Sandquist E.L., Schaefer G.H., Farrington C.D., Monnier J.D.,
Anugu N., Lanthermann C., Klement R., Ennis J., Setterholm B.R.,
Gardner T., Kraus S., Davies C.L., Orosz J.A.
<Astron. J., 166, 29 (2023)>
=2023AJ....166...29L 2023AJ....166...29L
ADC_Keywords: Stars, double and multiple; Spectra, optical; Spectra, infrared;
Radial velocities; Photometry; Positional data
Keywords: Stellar ages ; Interferometric binary stars ; White dwarf
stars ; Stellar evolution ; Open star clusters ; Spectroscopic
binary stars
Abstract:
We present measurements of the interferometrically resolved binary
star system 12Com and the single giant star 31 Com in the cluster Coma
Berenices. 12Com is a double-lined spectroscopic binary system
consisting of a G7 giant and an A3 dwarf at the cluster turnoff. Using
an extensive radial velocity data set and interferometric measurements
from the Palomar Testbed Interferometer and the Center for High
Angular Resolution Astronomy array, we measured masses
M1=2.64±0.07M☉ and M2=2.10±0.03M☉. Interferometry also
allows us to resolve the giant and measure its size as
R1=9.12±0.12±0.01R☉. With the measured masses and radii,
we find an age of 533±41±42Myr. For comparison, we measure the
radius of 31Com to be 8.36±0.15R☉. Based on the photometry and
radius measurements, 12ComA is likely the most evolved bright star in
the cluster, large enough to be in the red giant phase, but too small
to have core helium burning. Simultaneous knowledge of 12ComA's mass
and photometry puts strong constraints on convective core overshooting
during the main-sequence phase, which in turn reduces systematic
uncertainties in the age. Increased precision in measuring this system
also improves our knowledge of the progenitor of the cluster white
dwarf WD1216+260.
Description:
We analyzed 16 spectra from the ELODIE archive, originally taken over
a 26month period at the 1.93m telescope at OHP (P.I. X. Delfosse). The
spectra have a spectral resolution of R=42000 with a signal-to-noise
ratio (S/N) averaging over 200. The spectra covered 4000-6800Å and
were reduced using the ELODIE pipeline.
A larger number of observations were obtained using the Michigan
InfraRed Combiner-eXeter (MIRC-X) beam combiner at the Center for High
Angular Resolution Astronomy (CHARA) array at the Mt Wilson
Observatory. The MIRC-X instrument interferes the light from up to six
telescopes, resulting in visibility measurements on 15 baselines and
20 closure phase triangles. All MIRC-X measurements were taken in the
H-band using the R=50(Prism50), R=102(Prism102), or R=190(Grism190)
spectral modes. Visibilities and closure phases were obtained using
the standard MIRC-X pipeline version 1.3.3-1.3.5.
Objects:
---------------------------------------------
RA (2000) DE Designation(s)
---------------------------------------------
12 22 30.31 +25 50 46.1 12 Com = * 12 Com
12 51 41.92 +27 32 26.5 31 Com = * 31 Com
---------------------------------------------
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table1.dat 35 14 New radial velocity measures for 12 Com
table3.dat 72 3794 Visibilities for 12 Com
table4.dat 89 3956 Closure phases for 12 Com
table6.dat 52 9 Fitted positions for 12 Com
table8.dat 57 80 Photometry of 31 Com and 12 Com
--------------------------------------------------------------------------------
See also:
B/pollux : POLLUX database of synthetic stellar spectra (Palacios+ 2010-2021)
II/84 : 13-color photometry of 1380 bright stars (Johnson+ 1975)
III/150 : Perkins Revised MK Types for the Cooler Stars (Keenan+ 1989)
I/259 : The Tycho-2 Catalogue (Hog+ 2000)
I/345 : Gaia DR2 (Gaia Collaboration, 2018)
I/352 : Distances to 1.47 billion stars in Gaia EDR3 (Bailer-Jones+, 2021)
VII/233 : The 2MASS Extended sources (IPAC/UMass, 2003-2006)
J/AJ/114/699 : Spectrophotometry in open clusters (Clampitt+ 1997)
J/A+A/337/403 : Low-mass stars evolutionary models (Baraffe+ 1998)
J/A+A/333/231 : O-M stars model atmospheres (Bessell+ 1998)
J/ApJ/521/682 : Binaries in the Praesepe and Coma clusters (Abt+, 1999)
J/MNRAS/365/447 : Stellar members of Coma Berenices cluster (Casewell+, 2006)
J/AJ/135/209 : Rotational & radial velocities HIP giants (Massarotti+, 2008)
J/A+A/491/951 : Positions and cross-references in Coma Ber (Mermilliod+ 2008)
J/A+A/520/A52 : 31 Com radial velocities (Strassmeier+, 2010)
J/A+A/580/A23 : Stroemgren-Crawford uvbyβ photometry (Paunzen, 2015)
J/AJ/152/213 : Interferometry & spectroscopy sigma Orionis (Schaefer+, 2016)
J/A+A/624/L11 : Coma Berenices neighbor moving group (Fuernkranz+, 2019)
J/ApJ/877/12 : Coma Ber & a Neighbor Stellar Group tidal tails (Tang+, 2019)
J/A+A/649/A6 : Gaia Catalogue of Nearby Stars (Gaia collaboration, 2021)
J/ApJ/917/11 : Metallicities of Coma Berenices bona fide (Souto+, 2021)
J/AJ/164/184 : ARMADA. II. Binaries astrometry & RVel (Gardner+, 2022)
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 11 F11.5 d BJD [51888/52041] Barycentric Julian Date of
observation, BJD-2400000
13- 18 F6.2 km/s RVelA [-20.4/22.26] Radial velocity,
heliocentrically-corrected, component A
20- 23 F4.2 km/s e_RVelA [0.21/0.22] Uncertainty in RVelA
25- 30 F6.2 km/s RVelB [-30.7/18.22] Radial velocity,
heliocentrically-corrected, component B
32- 35 F4.2 km/s e_RVelB [1.26/2.63] Uncertainty in RVelB
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table3.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 11 F11.5 d HJD [53127/59366] Heliocentric Julian Date of
observation, HJD-2400000
13- 18 F6.4 um lambda [1.48/2.23] wavelength
20- 25 F6.4 um e_lambda [0.007/0.4] wavelength uncertainty
27- 34 F8.6 --- v2 [0.001/1.15] Observable (squared) visibility
36- 43 F8.6 --- e_v2 [0.001/0.16] Visibility uncertainty
45- 54 F10.5 m u [-245/300] baseline
56- 65 F10.5 m v [-273/312] baseline
67- 72 A6 --- Conf Configuration
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table4.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 11 F11.5 d HJD [59012/59366] Heliocentric Julian Date of
observation, HJD-2400000
13- 18 F6.4 um lambda [1.48/1.73] wavelength
20- 25 F6.4 um e_lambda [0.007/0.04] wavelength uncertainty
27- 32 F6.2 deg phi [-84.6/94.7] orientation angle error ellipse
34- 38 F5.2 deg e_phi [0.8/53] Uncertainty in phi
40- 49 F10.5 m u1 [-218/300] baseline
51- 58 F8.4 m v1 [-14.1/312] baseline
60- 69 F10.5 m u2 [-245/108] baseline
71- 80 F10.5 m v2 [-273/211] baseline
82- 89 A8 --- Conf Configuration
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table6.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 1 I1 "month" Obs.M UT Date, numeric month
3- 4 I2 d Obs.D UT Date, day in month
6- 9 I4 yr Obs.Y [2020/2021] UT Date, year
11- 19 F9.3 d HJD [59012/59366] Heliocentric Julian Date of
observation, HJD-2400000
21- 26 F6.3 mas rho [13.4/17.5] angular separation
28- 33 F6.2 deg theta [6.5/351] position angle of separation vector,
East of North
35- 39 F5.3 mas eMaj [0.06/0.09] major axis size of error ellipse
(σMaj)
41- 45 F5.3 mas eMin [0.01/0.06] minor axis size of error ellipse
(σMin)
47- 52 F6.2 --- phi [37.2/112] orientation angle of error ellipse
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table8.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 6 A6 --- Filt Filter name
8- 13 I6 0.1nm lambda [1565/220883] Effective central wavelength of
observation
15- 19 F5.2 mag omag31 [2.7/10.1]? Observed magnitude in Filter for
31 Com
21- 25 F5.3 mag e_omag31 [0.003/0.9]? Uncertainty in omag31
27- 34 E8.2 10+7W/m3 F31 [2e-16/5e-11]? Flux density, at lambda,
31 Com, erg/s/cm2/A
36- 39 F4.2 mag omag12 [2.47/7.35]? Observed magnitude in Filter for
12 Com
41- 45 F5.3 mag e_omag12 [0.003/0.3]? Uncertainty in omag12
47- 54 E8.2 10+7W/m3 F12 [2e-16/6e-11]? Flux density, at lambda-eff,
12 Com, erg/s/cm2/A
56- 57 I2 --- Ref [1/15] References (1)
--------------------------------------------------------------------------------
Note (1): References as follows:
1 = Gondhalekar+, 1980A&A....85..272G 1980A&A....85..272G
2 = Johnson & Mitchell, 1975, II/84
3 = Paunzen+, 2015, J/A+A/580/A23
4 = Morel & Magnenat+, 1978, II/7
5 = Hog+, 2000, J/A+A/355/L27
6 = Gaia Collaboration+, 2021, J/A+A/649/A6
7 = Flynn & Mermilliod, 1991A&A...250..400F 1991A&A...250..400F
8 = Skrutskie+, 2006, VII/233
9 = Wright+, 2010AJ....140.1868W 2010AJ....140.1868W
10 = Murakami+, 2007PASJ...59S.369M 2007PASJ...59S.369M
11 = Dzervitis & Paupers, 1990ISKZ...33...58D 1990ISKZ...33...58D
12 = Rufener+, 1988csmg.book.....R 1988csmg.book.....R
13 = Clampitt & Burstein+, 1997, J/AJ/114/699
14 = Blanton+, 2017AJ....154...28B 2017AJ....154...28B
15 = Kornilov+, 1991TrSht..63....1K 1991TrSht..63....1K
--------------------------------------------------------------------------------
History:
From electronic version of the journal
(End) Prepared by [AAS], Coralie Fix [CDS], 05-Feb-2024