J/A+A/703/A193 Berkeley 59 members (Wiesneth+, 2025)
Internal dynamics and structure of Cepheus OB4. The asymmetric expansion of
Berkeley 59.
Wiesneth B, Muzic K., Almendros-Abad V.
<Astron. Astrophys. 703, A193 (2025)>
=2025A&A...703A.193W 2025A&A...703A.193W (SIMBAD/NED BibCode)
ADC_Keywords: Clusters, open ; Stars, pre-main sequence ;
Effective temperatures ; Extinction ; Optical
Keywords: stars: kinematics and dynamics - stars: pre-main sequence -
open clusters and associations: individual: Berkeley 59 -
open clusters and associations: individual: Cepheus OB4
Abstract:
Accurate measurements of the internal dynamics of young stellar
clusters can be used to extract crucial information about their
formation process. With Gaia, we are now able to trace stellar motions
and study the dynamics of star clusters with unprecedented precision.
A fundamental requirement for this analysis is a well-defined and
reliable list of probable members.
We examine d a region with a radius of a 2° in Cepheus OB4,
centered on the young cluster Berkeley 59, to build a reliable
candidate member list. Our catalog enables the determination of
structural and kinematic parameters of the cluster, as well as other
properties of its stellar population.
We compiled a catalog of optical and near-infrared photometry, along
with precise positions and proper motions from Gaia DR3, for sources
in the Cepheus OB4 field. Membership probabilities were determined
using a probabilistic random forest algorithm and further refined by
requiring HR diagram positions consistent with a young age. From a
list of 1030 probable members, we estimate a distance of 1009±12pc
to Berkeley 59. Masses, extinction, and ages were derived by fitting
the spectral energy distributions to atmospheric and evolutionary
models, while internal dynamics was analyzed using proper motions
relative to the cluster's mean motion.
Berkeley 59 exhibits an asymmetric expansion pattern with velocity
increasing outward and a preferred motion toward the north. The IMF
between 0.4 and 7M☉ follows a single power law
(dN/dM∝M-alpha), with the slope alpha=2.3±0.3, consistent
with Salpeter's slope and previous studies in the region. The region's
median age, estimated from the HR diagram, is 2.9Myr. The velocity
dispersion of Berkeley 59 exceeds the virial velocity dispersion
derived from its total mass (650±30M☉) and half-mass radius
(1.71±0.13pc). The 2D motions of a stellar group located ∼1°
north of Berkeley 59 provide further support for the previously
proposed triggered star formation scenario.
Description:
In this table, we list source identifiers and coordinates from Gaia
DR3, as well as the effective temperature and extinction derived using
SED fitting.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table3.dat 54 1030 Members selected in this work, along with the
Teff and AV from the SED fitting
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See also:
I/355 : Gaia DR3 Part 1. Main source (Gaia Collaboration, 2022)
Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 19 I19 --- GaiaDR3 Source Identifier from Gaia DR3
21- 22 I2 h RAh Right Ascension (ICRS) at Ep=2016.0
24- 25 I2 min RAm Right Ascension (ICRS) at Ep=2016.0
27- 31 F5.2 s RAs Right Ascension (ICRS) at Ep=2016.0
33 A1 --- DE- Declination sign (ICRS) at Ep=2016.0
34- 35 I2 deg DEd Declination (ICRS) at Ep=2016.0
37- 38 I2 arcmin DEm Declination (ICRS) at Ep=2016.0
40- 43 F4.1 arcsec DEs [0/60] Declination (ICRS) at Ep=2016.0
45- 49 I5 K Teff ? Effective temperature
51- 54 F4.2 mag Av ? Extinction
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Acknowledgements:
Koraljka Muzic, kmuzic(at)fc.ul.pt
(End) Patricia Vannier [CDS] 26-Sep-2025