J/other/RAA/21.93 74 new open clusters found in Gaia DR2 (He+, 2021)
A catalogue of 74 new open clusters found in Gaia Data-Release 2.
He Z.-H., Xu Y., Hao C.-J., Wu Z.-Y., Li J.-J.
<Res. Astron. Astrophys. 21, 93 (2021)>
=2021RAA....21...93H 2021RAA....21...93H (SIMBAD/NED BibCode)
ADC_Keywords: Milky Way ; Clusters, open ; Proper motions ; Optical
Keywords: Galaxy: open clusters - methods: data analysis - surveys
Abstract:
Based on astrometric data from Gaia Data-Release 2 (DR2), we employ an
un- supervised machine learning method to blindly search for open star
clusters in the Milky Way within the Galactic latitude range of
|b|<20degree. In addition to 2080known clusters, 74 new open cluster
candidates are found. In this work, we present the positions, apparent
radii, parallaxes, proper motions and member stars of these
candidates. Meanwhile, to obtain the physical parameters of each
candidate cluster, stellar isochrones are fit to the photometric data.
The results show that the apparent radii and the observed proper
motion dispersions of these new candidates are consistent with those
of open clusters previously identified in Gaia DR2.
Description:
Adopting the clustering algorithm DBSCAN, we used the positions,
parallaxes, and proper motions of nearly 170 million stars within the
galactic latitude range |b|<20° and parallax plx>0.2mas in Gaia
DR2 to search for unknown OCs. We cross-matched our initial sample
with previous star cluster catalogues, and after performing several
vetting stages, we obtained a catalogue of 74 new OC candidates. We
fitted isochrones to these candidates and obtained their corresponding
physical parameters. The apparent radii and observed proper motion
dispersions of the new cluster candidates were consistent with those
of OCs previously found in Gaia DR2.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
new-oc.dat 82 74 New open clusters (table 1)
members.dat 223 3754 Members
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See also:
I/345 : Gaia DR2 (Gaia Collaboration, 2018)
J/A+A/633/A99 : Gaia DR2 open clusters in the Milky Way. II
(Cantat-Gaudin+, 2020)
Byte-by-byte Description of file: new-oc.dat
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Bytes Format Units Label Explanations
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1- 2 I2 --- OC [1/74] Open cluster identification number
4- 10 F7.3 deg GLON Galactic longitude
12- 18 F7.3 deg GLAT Galactic latitude
20- 23 F4.2 deg r Apparent radius)
25- 27 I3 --- Nstar Number of member stars
29- 30 I2 --- Ncore Number of cores
32- 35 F4.2 mas plx Parallax
37- 40 F4.2 mas s_plx Parallax dispersion
42- 46 F5.2 mas/yr pmRA Proper motion in RA, pmRA*cosDE
48- 51 F4.2 mas/yr s_pmRA pmRA dispersion
53- 57 F5.2 mas/yr pmDE Proper motion in DE
59- 62 F4.2 mas/yr s_pmDE pmDE dispersion
64- 67 F4.1 mag m-M Distance modulus
69- 72 F4.2 [yr] logAge Age
74- 76 F3.1 mag AG Extinction
78- 82 F5.3 --- Z Metal fraction
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Byte-by-byte Description of file: members.dat
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Bytes Format Units Label Explanations
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1- 19 I19 --- GaiaDR2 Gaia DR2 source ID
22- 41 F20.16 deg GLON Gaia DR2 Galactic longitude
43- 64 F22.18 deg GLAT Gaia DR2 Galactic latitude
66- 84 F19.17 mas plx Gaia DR2 parallax
86-105 F20.18 mas e_plx Gaia DR2 parallax error
107-128 F22.19 mas/yr pmRA Gaia DR2 proper motion in RA, pmRA*cosDE
130-149 F20.18 mas/yr e_pmRA Gaia DR2 pmRA error
151-172 F22.19 mas/yr pmDE Gaia DR2 proper motion in DE
174-193 F20.18 mas/yr e_pmDE Gaia DR2 pmDE error
195-204 F10.7 mag Gmag Gaia DR2 G-band mean magnitude (Vega)
206-218 F13.10 mag BP-RP ? Gaia DR2 BP-RP colour
220 I1 --- Core [0/1] Core (1) or border (0)
222-223 I2 --- OC [1/74] Open cluster identification number
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Acknowledgements:
Zhi-Hong He,, hezh(at)pmo.ac.cn
(End) Patricia Vannier [CDS] 28-Oct-2020