J/A+A/650/A67 Blue and yellow straggler stars in open clusters (Rain+, 2021)
A new, Gaia-based, catalogue of blue straggler stars in open clusters.
Rain M.J., Ahumada J.A., Carraro G.
<Astron. Astrophys. 650, A67 (2021)>
=2021A&A...650A..67R 2021A&A...650A..67R (SIMBAD/NED BibCode)
ADC_Keywords: Clusters, open ; Stars, blue ; Stars, peculiar
Keywords: catalogs - blue stragglers
Abstract:
Blue straggler stars are exotic objects present in all stellar
environments whose nature and formation channels are still partially
unclear. They seem to be particularly abundant in open clusters (OCs),
thus offering a unique chance to tackle these problems statistically.
We aim at building up a new and homogeneous catalogue of blue
straggler stars (BSS) in Galactic OCs using Gaia to provide a more
solid assessment of these stars membership. Then, we aim at exploring
possible relationships of the straggler abundance with the parent
cluster structural and dynamical parameters. As a by-product, we also
search for possible yellow straggler stars (YSS), which are believed
to be stragglers in a more advanced evolution stage.
We employ photometry, proper motions, and parallaxes extracted from
Gaia DR2 for 408 Galactic star clusters and searched for stragglers
within them after performing a careful membership analysis.
The number of BBS emerging from our more stringent, selection criteria
turns out to be significantly smaller than in previous versions of
this catalogue. OCs are therefore not anymore a preferable environment
for this kind of stars. Besides, we found that BSS start to appear in
clusters with ages larger than log(t)∼8.7 and are therefore absent
in very young star clusters. The present catalogue supersedes the
previous one from Ahumada et al. (2007A&A...463..789A 2007A&A...463..789A, Cat.
J/A+A/463/789) in several ways: membership assessment, number of
stragglers found, and so forth. The new list includes 889 BSS and 77
YSS candidates in 408 OCs.
We expect this catalogue to be the basis for a new round of studies of
blue and yellow straggler stars.
Description:
Catalogue based on the photometry and astrometric solution of Gaia
DR2. An amount of 896 blue-straggler and 77 yellow-straggler
candidates were found in 408 galactic open clusters of all ages. All
the candidates were carefully selected from their position in the
colour-magnitude diagram. Mean cluster parameters and individual data
for every blue and yellow straggler candidate are reported.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
clusters.dat 79 408 Open cluster data (table 3)
bss.dat 105 897 Blue stragglers in open clusters (table 4)
yss.dat 104 77 Yellow stragglers in open clusters
notes.dat 80 593 Notes
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See also:
I/345 : Gaia DR2 (Gaia Collaboration, 2018)
J/A+A/463/789 : Blue stragglers in open clusters (Ahumada+, 2007)
Byte-by-byte Description of file: clusters.dat
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Bytes Format Units Label Explanations
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1- 13 A13 --- Cluster Cluster name
15- 21 F7.3 deg RAdeg Right ascension (J2000.0)
23- 29 F7.3 deg DEdeg Declination (J2000.0)
31- 35 F5.2 [yr] log(Age) Decimal logarithm of the age
37- 41 F5.3 mag E(B-V) Reddening
43- 49 F7.3 mas/yr pmRA Proper motion along RA, pmRA*cosDE
51- 57 F7.3 mas/yr pmDE Proper motion along DE
59- 63 F5.3 mas plx Parallax
65- 71 F7.1 pc Dist Distance
73- 75 I3 --- NBSS [0/103] Number of blue straggler candidates
77 I1 --- NYSS [0/4] Number of yellow straggler candidates
79 A1 --- Notes [*] * indicates a note detailed in
notes.dat file
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Byte-by-byte Description of file: bss.dat yss.dat
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Bytes Format Units Label Explanations
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1- 13 A13 --- Cluster Cluster name
15- 33 I19 --- GaiaDR2 Gaia DR2 source_id
35- 44 F10.6 deg RAdeg Gaia DR2 right ascension (ICRS) at Ep=2015.5
46- 55 F10.6 deg DEdeg Gaia DR2 declination (ICRS) at Ep=2015.5
57- 64 F8.4 mas/yr pmRA Gaia DR2 proper motion along RA, pmRA*cosDE
66- 72 F7.3 mas/yr pmDE Gaia DR2 proper motion along DE
74- 80 F7.4 mas plx Gaia DR2 parallax
82- 87 F6.3 mag Gmag Gaia DR2 mean G magnitude
89- 94 F6.3 mag BP-RP Gaia DR2 BP-RP colour index
96- 98 F3.1 --- Pmemb Membership probability
100-105 F6.3 arcmin r Location from cluster center
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Byte-by-byte Description of file: notes.dat
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Bytes Format Units Label Explanations
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1- 13 A13 --- Cluster Cluster name
15- 80 A66 --- Text Text of note
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Acknowledgements:
Maria Jose Rain, mariajoserain(at)gmail.com
(End) Maria Jose Rain [UniPD], Patricia Vannier [CDS] 03-Mar-2021