J/A+A/584/A26 Cosmography of OB stars in the solar neighbourhood (Bouy+, 2015)
Cosmography of OB stars in the solar neighbourhood.
Bouy H., Alves J.
<Astron. Astrophys., 584, A26-26 (2015)>
=2015A&A...584A..26B 2015A&A...584A..26B (SIMBAD/NED BibCode)
ADC_Keywords: Associations, stellar ; Stars, nearby ; Parallaxes, trigonometric
Keywords: stars: massive - solar neighborhood -
open clusters and associations: general
Abstract:
We construct a 3D map of the spatial density of OB stars within 500pc
from the Sun using the Hipparcos catalogue and find three large-scale
stream-like structures that allow a new view on the solar
neighbourhood. The spatial coherence of these blue streams and the
monotonic age sequence over hundreds of parsecs suggest that they are
made of young stars, similar to the young streams that are conspicuous
in nearby spiral galaxies. The three streams are 1) the Scorpius to
Canis Majoris stream, covering 350pc and 65Myr of star formation
history; 2) the Vela stream, encompassing at least 150pc and 25Myr of
star formation history; and 3) the Orion stream, including not only
the well-known Orion OB1abcd associations, but also a large previously
unreported foreground stellar group lying only 200pc from the Sun. The
map also reveals a remarkable and previously unknown nearby OB
association, between the Orion stream and the Taurus molecular clouds,
which might be responsible for the observed structure and star
formation activity in this cloud complex. This new association also
appears to be the birthplace of Betelgeuse, as indicated by the
proximity and velocity of the red giant. If this is confirmed, it
would solve the long-standing puzzle of the origin of Betelgeuse. The
well-known nearby star-forming low-mass clouds, including the nearby T
and R associations Lupus, Cha, Oph, CrA, Taurus, Vela R1, and various
low-mass cometary clouds in Vela and Orion, appear in this new view of
the local neighbourhood to be secondary star formation episodes that
most likely were triggered by the feedback from the massive stars in
the streams. We also recover well-known star clusters of various ages
that are currently cruising through the solar neighbourhood. Finally,
we find no evidence of an elliptical structure such as the Gould belt,
a structure we suggest is a 2D projection effect, and not a physical
ring.
Description:
We use the Hipparcos catalogue to revisit the cosmography of OB stars
in the solar neighbourhood. Because of the drawbacks mentioned above,
we focus on the 3D spatial distribution using modern full 3D data
analysis and interactive visualization techniques instead of 2D
projections, and refrain from using velocities as a discovery
criterion for stellar groups.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table3.dat 57 123 Members of the candidate new stellar groups
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See also:
I/311 : Hipparcos, the New Reduction (van Leeuwen, 2007)
Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 8 A8 --- Group New stellar group name (1)
10- 14 I5 --- HIP HIP number
16- 24 F9.5 deg GLON Galactic longitude
26- 34 F9.5 deg GLAT Galactic latitude
36- 47 A12 --- SpType MK spectral type
49- 52 F4.2 mag plx HIP parallax (Cat. I/311)
54- 57 F4.2 mag e_plx rms uncertainty on plx
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Note (1): New stellar group names are Monorion, Taurion, Orion X and Vela OB5.
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 27-Jan-2016