J/AJ/132/749 Rotational velocities of O stars in clusters (Wolff+, 2006)
Stellar rotation: a clue to the origin of high-mass stars?
Wolff S.C., Strom S.E., Dror D., Lanz L., Venn K.
<Astron. J., 132, 749-755 (2006)>
=2006AJ....132..749W 2006AJ....132..749W
ADC_Keywords: Clusters, open ; Stars, O ; Rotational velocities
Keywords: open clusters and associations: individual (NGC 6611, Orion) -
stars: rotation
Abstract:
We present the results of a study aimed at assessing whether low and
high-mass stars form similarly. Our approach is (1) to examine the
observed projected rotational velocities among a large sample of newly
formed stars spanning a range in mass between 0.2 and 50M☉ and
(2) to search for evidence of a discontinuity in rotational properties
that might indicate a difference in the stellar formation process at
some characteristic mass. Our database includes recently published
values of vsini for young intermediate and low-mass stars in Orion, as
well as new observations of O stars located in young clusters and OB
associations.
Description:
Observations (the high-resolution sample) of nine O stars in NGC 6611
were obtained in 2005 May using the Hydra multiobject fiber
spectrograph on WIYN as part of a more extensive study of stellar
rotation in this cluster. In conjunction with an echelle grating and
an order-separating filter, these observations with WIYN Hydra yielded
spectra with R∼20000, spanning the wavelength range 4450-4590Å. In
addition to our NGC 6611 program stars, 12 stars with spectral types
from O4 to B0 with known values of vsini were observed on the same
nights with the same instrumental configuration to serve as rotation
standard stars.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 77 44 *Stellar Data
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Note on table1.dat: in the original table, stars of Cyg OB2 association
have B1950 positions; these were converted to J2000 here.
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Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 8 A8 --- Cluster Cluster or association name
10- 18 A9 --- Star Star name or number (1)
20- 22 I3 --- WEBDA ? WEBDA Database number
(http://www.univie.ac.at/webda ) (2)
24- 25 I2 h RAh Hour of Right Ascension (J2000)
27- 28 I2 min RAm Minute of Right Ascension (J2000)
30- 34 F5.2 s RAs Second of Right Ascension (J2000)
36 A1 --- DE- Sign of the Declination (J2000)
37- 38 I2 deg DEd Degree of Declination (J2000)
40- 41 I2 arcmin DEm Arcminute of Declination (J2000)
43- 46 F4.1 arcsec DEs Arcsecond of Declination (J2000)
48- 54 A7 --- SpType MK spectral type
56- 59 F4.2 [K] logT Log of the effective temperature
61- 64 F4.2 [solLum] logL Log of the bolometric luminosity
66- 67 I2 solMass Mass Stellar mass
69- 71 I3 km/s vsini Apparent rotational velocity
73- 77 F5.2 [cm2/s] logJ/M Log of the specific angular momentum
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Note (1): Nomenclature note:
For Cyg OB2, [MT91] NNN in Simbad
Note (2): Nomenclature note:
For IC 1805, IC 1805 NNN in Simbad
For NGC 2244, NGC 2244 NNN in Simbad
For NGC 6611, NGC 6611 NNN in Simbad
For NGC 7380, WEBDA number not in Simbad
(star No 31 is [MJD95] J224750.61+580512.2)
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History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Patricia Vannier [CDS] 08-Feb-2008