J/A+A/486/453 NIR photometry of early-type stars in Cyg OB2 (Comeron+, 2008)
The outskirts of Cygnus OB2.
Comeron F., Pasquali A., Figueras F., Torra J.
<Astron. Astrophys., 486, 453-466 (2008)>
=2008A&A...486..453C 2008A&A...486..453C
ADC_Keywords: Clusters, open ; Stars, early-type ; Photometry, infrared
Keywords: stars: early-type -
Galaxy: open clusters and associations: individual: Cygnus OB2 -
Galaxy: open clusters and associations: individual: Cygnus OB9
Abstract:
Cygnus OB2 is one of the richest OB associations in the local Galaxy,
and is located in a vast complex containing several other
associations, clusters, molecular clouds, and HII regions. However,
the stellar content of Cygnus OB2 and its surroundings remains rather
poorly known largely due to the considerable reddening in its
direction at visible wavelength.
We investigate the possible existence of an extended halo of
early-type stars around Cygnus OB2, which is hinted at by
near-infrared color-color diagrams, and its relationship to Cygnus OB2
itself, as well as to the nearby association Cygnus OB9 and to the
star forming regions in the Cygnus X North complex.
Candidate selection is made with photometry in the 2MASS all-sky point
source catalog. The early-type nature of the selected candidates is
confirmed or discarded through our infrared spectroscopy at low
resolution. In addition, spectral classifications in the visible are
presented for many lightly-reddened stars.
Description:
We carried out near-infrared spectroscopic observations during two
observing runs at the Calar Alto observatory. The first one took place
from 16 June to 1 July 2002 at the 1.23m telescope, and the second
one from 31 July to 2 August 2004 at the 2.2m telescope.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
tables.dat 83 230 JKHs photometry of early-type stars (tables 1-9)
notes.dat 80 93 Individual notes
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See also:
J/AJ/101/1408 : Massive stars in Cyg OB2. (Massey+ 1991)
J/AJ/107/1433 : Cygnus OB2 polarimetry (Kobulnicky+, 1994)
J/A+AS/111/407 : VI Cygni red + reddened stars (Parthasarathy+, 1995)
J/MNRAS/298/753 : Variables in Cygnus OB2 (Pigulski+ 1998)
J/ApJS/149/123 : WSRT survey of Cygnus OB2 (Setia Gunawan+, 2003)
J/A+A/464/211 : Chandra and near-IR obs. of Cyg OB2 (Albacete Colombo+, 2007)
J/A+A/472/557 : Cygnus OB2 region 610MHz sources (Marti+, 2007)
J/A+A/474/495 : X-ray flares from CygOB2 young stars (Albacete Colombo+ 2007)
Byte-by-byte Description of file: tables.dat
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Bytes Format Units Label Explanations
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1 I1 --- Tab [1/9] Original table number (1)
3 A1 ---- Type Type of star (2)
5- 7 I3 --- [CPF2008] Star sequential number
9- 10 I2 h RAh Right ascension (J2000)
12- 13 I2 min RAm Right ascension (J2000)
15- 19 F5.2 s RAs Right ascension (J2000)
21 A1 --- DE- Declination sign (J2000)
22- 23 I2 deg DEd Declination (J2000)
25- 26 I2 arcmin DEm Declination (J2000)
28- 31 F4.1 arcsec DEs Declination (J2000)
33- 38 F6.3 mag Jmag ? J magnitude
40- 45 F6.3 mag Hmag ? H magnitude
47- 52 F6.3 mag Ksmag Ks magnitude
54- 60 A7 --- SpType Visual MK spectral classification
62- 76 A15 --- OName Other name
78- 83 A6 --- Notes Notes, in notes.dat file
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Note (1): Titles of original tables as follows:
1 = Stars with reddened, featureless spectra
2 = Emission line stars
3 = Lightly reddened OB stars
4 = Foreground intermediate-type stars and lightly reddened,
unclassified stars
5 = Late B-F star lightly reddened stars
6 = Red giant candidates
7 = Carbon stars
8 = Likely long-period variables
9 = Extremely red objects
Note (2): Type as follows:
F = Foreground stars
L = Lightly reddened stars with no classification in the visible
U = Unreddened or lightly reddened stars
R = Reddened stars
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Byte-by-byte Description of file: notes.dat
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Bytes Format Units Label Explanations
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1- 2 I2 --- Note Note number
4- 80 A77 --- Text Text of the note
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 30-Sep-2008