J/AJ/168/282 Candidate stars parameters in Praesepe & a Persei (Brandner+, 2024)
The radiative-convective gap: fact or fiction?
Brandner W., Sorg A., Roser S., Schilbach E.
<Astron. J., 168, 282 (2024)>
=2024AJ....168..282B 2024AJ....168..282B
ADC_Keywords: Clusters, open; Stars, distances; Photometry; Optical
Keywords: Open star clusters ; Stellar abundances ; Stellar ages ;
Stellar evolution ; Stellar atmospheres ; Stellar colors ;
Stellar effective temperatures ; Stellar luminosities ; Stellar masses
Abstract:
Gaia characterizes the stellar populations of nearby open clusters
with unprecedented precision. We investigate the Bohm-Vitense gap,
which has been found as a prominent feature in the stellar sequence of
open clusters. Using PARSEC isochrone fitting, we derive astrophysical
parameters for more than 1100 bona fide single stars each in Praesepe,
identify more than 1100 bona fide single stars in the α Persei
(Melotte 20) open cluster, and confirm their approximate match in
terms of age (∼710 and ∼45Myr) and metallicity ([M/H] ~+0.15 and
~+0.13 dex) to the Hyades and Pleiades, respectively. By merging data
of the cluster pairs, we improve number statistics. We do not find a
clear gap in the combined observational Gabs versus BP - RP
color-magnitude diagram (CMD) in the stellar mass range corresponding
to the location of the Bohm-Vitense gap. We reproduce gaps in
simulated Hyades-type CMDs randomly drawn from an initial mass
function. There is no strong evidence for a discontinuity originating
in the transition from radiative to convective energy transport in the
stellar photosphere. We conclude that the observed gaps in the stellar
sequences of open clusters could be explained by small number
statistics and the uneven mass-color relation at the transition from
spectral type A to F.
Description:
In the present paper, we aim to investigate the authenticity of the
gap aided by Gaia DR3's unprecedented astrometric and photometric
quality. Gaia DR3 data (Gaia Collab.+2022, I/355) provides proper
motions, parallaxes, and three-band photometry (G, GBP, GRP) for
over a billion sources observed between 25 July 2014 and 28 May 2017.
The wavelength of filter G is centered at 673nm, GBP at 532nm, and
GRP at 797nm.
Objects:
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RA (2000) DE Designation(s)
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08 39 58.36 +19 36 33.1 Praesepe = C 0837+201
03 26 50.56 +48 51 47.5 NAME Alpha Persei Cluster = Melotte 20
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 128 1393 Candidate members of the Praesepe cluster,
classified according to Gaia DR3, sorted by RA
table2.dat 126 1573 Candidate members of the Alpha Persei cluster,
classified according to Gaia DR3, sorted by RA
table6.dat 166 1129 Astrophysical parameters of bona fide single stars
in the Praesepe open cluster
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See also:
I/259 : The Tycho-2 Catalogue (Hog+ 2000)
II/246 : 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)
I/337 : Gaia DR1 (Gaia Collaboration, 2016)
I/352 : Distances to 1.47 billion stars in Gaia EDR3 (Bailer-Jones+, 2021)
I/355 : Gaia DR3 Part 1. Main source (Gaia Collaboration, 2022)
V/80 : Low-Mass Stars' Membership in Alpha Persei Cluster (Prosser 1992)
J/A+A/331/81 : Hyades membership (Perryman+ 1998)
J/A+A/438/1163 : Catalogue of Open Cluster Data (COCD) (Kharchenko+, 2005)
J/AJ/131/2967 : α Persei open cluster members (Makarov+, 2006)
J/A+A/489/403 : Line abundances for solar stars (Pace+, 2008)
J/ApJ/697/1578 : A debris disk study of Praesepe (Gaspar+, 2009)
J/A+A/616/A10 : 46 open clusters GaiaDR2 HR diagrams (Gaia Collaboration, 2018)
J/A+A/628/A66 : alpha Persei, Pleiades and Praesepe clusters (Lodieu+, 2019)
J/A+A/627/A4 : Praesepe (NGC 2632) and its tidal tails (Roeser+, 2019)
J/A+A/633/A38 : EW of 10 solar-type stars of Praesepe (D'Orazi+, 2020)
J/ApJ/919/100 : Abundances of 6 stars in Praesepe cluster (Vejar+, 2021)
J/A+A/668/A4 : LAMOST open clusters (Fu+, 2022)
J/MNRAS/509/421 : Galac. metallic. gradient with open clusters (Netopil+ 2022)
J/MNRAS/518/662 : Benchmarking MESA isochrones with Hyades (Brandner+, 2023)
J/AJ/165/108 : Properties of 600 bona fide stars in Hyades (Brandner+, 2023)
J/A+A/677/A162 : Pleiades bonafide single stars (Brandner+, 2023)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 19 I19 --- GaiaDR3 Gaia DR3 source identifier
21- 38 F18.14 deg RAdeg [86.3/153.1] Barycentric right ascension
(ICRS) at Ep=2016.0 (1)
40- 57 F18.15 deg DEdeg [-9.7/77.1] Barycentric declination (ICRS) at
Ep=2016.0 (1)
59- 65 F7.3 pc dpgeo [96.9/306] Median photogeometric distance
posterior (2)
67- 73 F7.3 pc e_dpgeo [96.1/302.4] The 16th quantile of dpgeo
75- 81 F7.3 pc E_dpgeo [98/309.1] The 84th quantile of dpgeo
83- 89 F7.4 mag Gmag [6.1/19.9] Gaia G band (673nm) apparent
magnitude (1)
91- 96 F6.4 mag e_Gmag [1e-4/7e-3] Uncertainty in Gmag
98- 104 F7.4 mag BPmag [6.3/21.2] Gaia BP band (532nm) apparent
magnitude (1)
106- 111 F6.4 mag e_BPmag [2e-4/0.19] Uncertainty in BPmag
113- 119 F7.4 mag RPmag [5.5/19.4] Gaia RP band (797nm) apparent
magnitude (1)
121- 126 F6.4 mag e_RPmag [2e-4/0.06] Uncertainty in RPmag
128 I1 --- Class [1/4] Object class (3)
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Note (1): Coordinates (ICRS at Ep=2016.0) and photometry from Gaia DR3 (I/355)
Note (2): Photo-geometric distance posteriors are according to Gaia EDR3 (I/352)
Note (3): Object class as follows:
1 = bona fide single star (1150 occurrences)
2 = likely binary or multiple star (160 occurrences)
3 = white dwarf (13 occurrences)
4 = peculiar Gaia DR3 BP-G versus G-RP color (70 occurrences)
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Byte-by-byte Description of file: table2.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 18 I18 --- GaiaDR3 Gaia DR3 source identifier
20- 36 F17.14 deg RAdeg [26.8/76.1] Barycentric right ascension (ICRS)
at Ep=2016.0 (1)
38- 55 F18.15 deg DEdeg [33.1/64.9] Barycentric declination (ICRS) at
Ep=2016.0 (1)
57- 63 F7.3 pc dpgeo [0/246.7] Median photogeometric distance
posterior (2)
65- 71 F7.3 pc e_dpgeo [0/232.5] The 16th quantile of dpgeo
73- 79 F7.3 pc E_dpgeo [0/333.8] The 84th quantile of dpgeo
81- 87 F7.4 mag Gmag [3.9/19.9] Gaia G band (673nm) apparent
magnitude (1)
89- 94 F6.4 mag e_Gmag [1e-4/7e-3] Uncertainty in Gmag
96- 102 F7.4 mag BPmag [3.9/21.8] Gaia BP band (532nm) apparent
magnitude (1)
104- 109 F6.4 mag e_BPmag [2e-4/0.3] Uncertainty in BPmag
111- 117 F7.4 mag RPmag [3.9/19.8] Gaia RP band (797nm) apparent
magnitude (1)
119- 124 F6.4 mag e_RPmag [2e-4/0.1] Uncertainty in RPmag
126 I1 --- Class [1/4] Object class (3)
--------------------------------------------------------------------------------
Note (1): Coordinates (ICRS at Ep=2016.0) and photometry from Gaia DR3 (I/355)
Note (2): Photo-geometric distance posteriors are according to Gaia EDR3 (I/352)
Note (3): Object class as follows:
1 = bona fide single star (1105 occurrences)
2 = likely binary or multiple star (339 occurrences)
3 = white dwarf (8 occurrences)
4 = peculiar Gaia DR3 BP-G versus G-RP color (121 occurrences)
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Byte-by-byte Description of file: table6.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 19 I19 --- GaiaDR3 Gaia DR3 source identifier
21- 30 F10.6 deg RAdeg [86.3/153.1] Barycentric right ascension
(ICRS) at Ep=2016.0 (1)
32- 40 F9.6 deg DEdeg [-9.7/77.1] Barycentric declination (ICRS)
at Ep=2016.0 (1)
42- 48 F7.3 pc dpgeo [96.9/306] Median photogeometric distance
posterior (2)
50- 56 F7.3 pc e_dpgeo [96.1/302.4] The 16th quantile of dpgeo
58- 64 F7.3 pc E_dpgeo [98/309.1] The 84th quantile of dpgeo
66- 72 F7.4 mag Gmag [7.3/19] Gaia G band (673nm) apparent
magnitude (1)
74- 79 F6.4 mag e_Gmag [1e-4/3e-3] Uncertainty in Gmag
81- 87 F7.4 mag BPmag [7.4/21] Gaia BP band (532nm) apparent
magnitude (1)
89- 94 F6.4 mag e_BPmag [2e-4/0.2] Uncertainty in BPmag
96- 102 F7.4 mag RPmag [7.1/17.7] Gaia RP band (797nm) apparent
magnitude (1)
104- 109 F6.4 mag e_RPmag [2e-4/0.02] Uncertainty in RPmag
111- 116 F6.4 Msun mass [0.19/2.2] Mass (3)
118- 123 F6.4 Msun e_mass [3e-3/0.1] Uncertainty in mass
125- 130 F6.4 [K] logT [3.4/4] Log effective temperature (3)
132- 137 F6.4 [K] e_logT [1e-3/0.03] Uncertainty in logT
139- 145 F7.4 [Lsun] logL [-2.5/1.5] Log Luminosity (3)
147- 152 F6.4 [Lsun] e_logL [7e-3/0.32] Uncertainty in logL
154- 159 F6.4 [cm/s2] logg [3.8/5.02] Log surface gravity (3)
161- 166 F6.4 [cm/s2] e_logg [1e-3/0.07] Uncertainty in logg
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Note (1): Coordinates (ICRS at Ep=2016.0) and photometry from Gaia DR3 (I/355)
Note (2): Photo-geometric distance posteriors are according to Gaia EDR3 (I/352)
Note (3): Stellar astrophysical parameters are based on PARSEC 1.2S
(Bressan+, 2012MNRAS.427..127B 2012MNRAS.427..127B) for log age [Myr]=8.85±0.03,
[M/H]=+0.15±0.04, Av=83.7mmag.
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History:
From electronic version of the journal
(End) Prepared by [AAS], Robin Leichtnam [CDS] 05-Sep-2025