J/MNRAS/518/662 Benchmarking MESA isochrones with the Hyades (Brandner+, 2023)
Benchmarking MESA isochrones against the Hyades single star sequence.
Brandner W., Calissendorff P., Kopytova T.
<Mon. Not. R. Astron. Soc. 518, 662-668 (2023)>
=2023MNRAS.518..662B 2023MNRAS.518..662B (SIMBAD/NED BibCode)
ADC_Keywords: Clusters, open ; Photometry ; Optical ; Stars, distances
Keywords: convection - stars: evolution - stars: fundamental parameters -
Hertzsprung-Russell and colour-magnitude diagrams - stars: interiors -
open clusters and associations: individual: Hyades
Abstract:
Based on GAIA EDR3, we revisit and update our sample of bonafide
single stars in the Hyades open cluster. The small observational
uncertainties in parallax and photometry of EDR3 result in a tightly
defined stellar sequence, which is ideal for the testing and
calibration of theoretical stellar evolutionary tracks and isochrones.
We benchmark the solar-scaled MESA evolutionary models against the
single star sequence. We find that the non-rotating MESA models for
[Fe/H]=+0.25 provide a good fit for stars with masses above 0.85, and
very low mass stars below 0.25M☉. For stars with masses between
0.25 and 0.85M☉the models systematically under predict the
observed stellar luminosity. One potential limitation of the models
for partially convective stars more massive than 0.35M☉is the
prescription of (superadiabatic) convection with the mixing-length
theory parameter αML tuned to match the Solar model. Below
0.35M☉, the increased scatter in the stellar sequence might be a
manifestation of the convective kissing instability, which is driven
by variations in the 3He nuclear energy production rate due to
instabilities at the convective core to envelope boundary. For a
Hyades-like stellar population, the application of solar-scaled models
to subsolar mass stars could result in a significant underestimate of
the age, or an overestimate of the metallicity. We suggest that future
grids of solar-scaled evolutionary stellar models could be
complemented by Hyades-scaled models in the mass range 0.25 to
0.85M☉.
Description:
GAIA EDR3 facilitates a refinement of the single star sequence
from Kopytova et al. (2016A&A...585A...7K 2016A&A...585A...7K, Cat. J/A+A/585/A7). Gaia
Collaboration et al. (2021A&A...649A...6G 2021A&A...649A...6G, Cat. J/A+A/649/A6)
published a GAIA Catalogue of Nearby Stars (GCNS) listing 920
candidate members of the Hyades. In order to reject photometric
outliers caused, e.g., by blends in the GAIA BP and RP bands, we first
applied a colour cut-off: -0.2mag≤BP-G≤3.2mag and
-0.3mag≤G-RP≤1.7mag. This rejected 30 sources, resulting in a sample
of 890 candidate members listed in Table 1.
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table1.dat 116 890 Single and multiple candidate members of the Hyades
cluster, classified according to GAIA photometry
and parallax, sorted by RA
--------------------------------------------------------------------------------
See also:
I/350 : Gaia EDR3 (Gaia Collaboration, 2020)
I/352 : Distances to 1.47 billion stars in Gaia EDR3
(Bailer-Jones+, 2021)
J/A+A/585/A7 : Hyades single stars fiducial photometry (Kopytova+, 2016)
J/A+A/649/A6 : Gaia Catalogue of Nearby Stars - GCNS (Gaia collaboration, 2021)
Byte-by-byte Description of file: table1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 19 A19 --- GaiaEDR3 GAIA EDR3 source_id
21- 33 F13.9 deg RAdeg Barycentric right ascension (ICRS) at Ep=2016.0
35- 47 F13.9 deg DEdeg Barycentric declination (ICRS) at Ep=2016.0
49- 54 F6.3 pc dpgeo Median photogeometric distance posterior
56- 61 F6.3 pc b_dpgeo 16th quantile photogeometric distance posterior
63- 69 F7.3 pc B_dpgeo 84th quantile photogeometric distance posterior
71- 77 F7.4 mag Gmag Gaia G magnitude
79- 84 F6.4 mag e_Gmag Gaia G magnitude uncertainty
86- 92 F7.4 mag BPmag Gaia BP magnitude
94- 99 F6.4 mag e_BPmag Gaia BP magnitude uncertainty
101-107 F7.4 mag RPmag Gaia RP magnitude
109-114 F6.4 mag e_RPmag Gaia RP magnitude uncertainty
116 I1 --- Flag [1/4] Note (1)
--------------------------------------------------------------------------------
Note (1): Note as follows:
1 = bonafide single star
2 = likely binary or multiple
3 = white dwarf
4 = peculiar Gaia EDR3 BP-G vs. G-RP colours
--------------------------------------------------------------------------------
Acknowledgements:
Wolfgang Brandner, brandner(at)mpia.de
(End) Patricia Vannier [CDS] 11-Aug-2022