J/A+A/705/A215 Galactic O-type runaway stars (Carretero-Castrillo+, 2026)
An observational study of rotation and binarity of Galactic O-type runaway
stars.
Carretero-Castrillo, M., Ribo M., Paredes J.M, Holgado G.,
Martinez-Sebastian C., Simon-Diaz S.
<Astron. Astrophys. 705, A215 (2026)>
=2026A&A...705A.215C 2026A&A...705A.215C (SIMBAD/NED BibCode)
ADC_Keywords: Milky Way ; Stars, O ; Stars, high-velocity ; Spectroscopy ;
Space velocities ; Rotational velocities ; Stars, distances ;
Optical
Keywords: binaries: spectroscopic - stars: early-type -
stars: kinematics and dynamics - stars: rotation -
supernovae: general - X-rays: binaries
Abstract:
Gaia Data Release 3 (DR3) data have revealed new massive runaway
stars, while large spectroscopic surveys now enable detailed
characterization studies. However, the relative contributions of
binary supernova (BSS) and dynamical ejection (DES) scenarios to
explain their runaway origin remain poorly constrained, particularly
in the Milky Way. We aim to characterize the largest sample of
Galactic O-type runaway stars ever investigated through their
kinematics, rotation, and binarity with the ultimate objective of
shedding light into their potential to identify signatures of their
dynamical origins. We use the GOSC-Gaia DR3 catalog of normal and
runaway stars, and IACOB spectroscopic information to build a sample
with 214 O-type stars with available information about projected
rotational velocities (vsini), and a subsample of 168 O-type stars
with additional information about their likely single (LS) or
single-lined (SB1) spectroscopic binary nature. We also consider an
additional sample of 65 double-lined (SB2) spectroscopic binaries. We
find that among our sample of Galactic O-type runaways, most (74%)
have vsini<200km/s. There are no fast-moving (VPEC2D>85km/s)
runaways being fast rotators (vsini≥200km/s), except for HD 124 979.
Runaways show lower SB1 fractions than normal stars, with no runaway
SB1 fast-rotating systems; on average, runaways rotate faster than
normal stars; and their runaway fraction is higher among fast rotators
(44%) vs. the slow rotators (34%). This is consistent with BSS
dominance for fast rotators. We also found that SB2 systems hardly
reach runaway velocities with a low runaway fraction (10%). Runaways
with VPEC2D>60km/s are mostly single and interpreted as DES
products, while runaways with VPEC2D>85km/s are also interpreted as
two-step products, with the binary V479 Sct/LS 5039 a likely example.
Finally, three of 12 runaway SB1 systems are high-mass X-ray binaries.
Our observational study reveals that Galactic O-type runaways are
dominated by slow rotators. The study points to a dominance of BSS
among fast-rotating runaways, and of DES and two-step among the
high-velocity ones. The observed trends provide valuable constraints
on models about runaway origins.
Description:
We cross-matched the GOSC-Gaia DR3 catalog computed in
Carretero-Castrillo et al. (2023A&A...679A.109C 2023A&A...679A.109C, Cat. J/A+A/679/A109)
with spectroscopic information from the IACOB project. Here we present
the resulting "rotation sample" including 214 Galactic O-type normal
and runaway stars with available projected rotational velocities. The
stars are listed i n decreasing order of their E values. E is the
normalized significance of the runaway nature of each star.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
tablea1.dat 128 214 Data of the O-type normal and runaway stars in
the rotation sample
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See also:
J/A+A/679/A109 : GaiaDR3 Galactic runaway O, Be stars
(Carretero-Castrillo+, 2023)
J/A+A/694/A250 : Bow shocks around runaway stars (Carretero-Castrillo+, 2025)
Byte-by-byte Description of file: tablea1.dat
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Bytes Format Units Label Explanations
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1- 15 A15 --- GOSC Most common name of the star from the
GOSC catalog
17- 35 I19 --- GaiaDR3 Gaia DR3 source identifier
37- 38 I2 h RAh Right ascension (ICRS) at Ep=2016.0
from Gaia DR3
40- 41 I2 min RAm Right ascension (ICRS) at Ep=2016.0
from Gaia DR3
43- 48 F6.3 s RAs Right ascension (ICRS) at Ep=2016.0
from Gaia DR3
50 A1 --- DE- Declination sign (ICRS) at Ep=2016.0
from Gaia DR3
52- 53 I2 deg DEd Declination (ICRS) at Ep=2016.0 from Gaia DR3
55- 56 I2 arcmin DEm Declination (ICRS) at Ep=2016.0 from Gaia DR3
58- 62 F5.2 arcsec DEs Declination (ICRS) at Ep=2016.0 from Gaia DR3
64- 73 F10.6 deg GLON Galactic longitude from Gaia DR3
75- 84 F10.6 deg GLAT Galactic latitude from Gaia DR3
86- 89 F4.2 kpc Dist Distance from the Sun (1)
91- 94 F4.2 kpc e_Dist Standard error of distance (1)
96-100 F5.2 mag Gmag G-band mean magnitude from Gaia DR3
102-106 A5 --- SpType Spectral Type from the GOSC catalog
108-112 F5.1 km/s Vpec2D Peculiar 2-dimensional (2D) velocity (1)
114-117 F4.1 km/s e_Vpec2D Standard error of peculiar 2D velocity (1)
119-122 F4.2 --- E Normalized significance of the runaway nature
of the star (1)
124-128 F5.1 km/s vsini Projected rotational velocity from the
IACOB project
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Note (1): computed in Carretero-Castrillo et al., 2023A&A...679A.109C 2023A&A...679A.109C,
Cat. J/A+A/679/A109.
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Acknowledgements:
Mar Carretero-Castrillo, mcarretero(at)fqa.ub.edu,
m.carretero.castrillo(at)gmail.com
(End) Patricia Vannier [CDS] 12-Jan-2026