J/AJ/128/1233 LkHα 101 and the young cluster in NGC 1579 (Herbig+, 2004)
LkHα 101 and the young cluster in NGC 1579.
Herbig G.H., Andrews S.M., Dahm S.E.
<Astron. J., 128, 1233-1253 (2004)>
=2004AJ....128.1233H 2004AJ....128.1233H
ADC_Keywords: Clusters, open ; Stars, emission ;
Stars, pre-main sequence ; Photometry, Cousins ;
Photometry, infrared ; Spectroscopy
Keywords: open clusters and associations: individual (NGC 1579) -
stars: emission-line, Be - stars: formation -
stars: individual (LkHα 101) - stars: pre-main-sequence
Abstract:
The central region of the dark cloud L1482 is illuminated by
LkHα 101, a heavily reddened (AV∼10mag) high-luminosity
(≥8x103LSun) star having an unusual emission-line spectrum plus
a featureless continuum. About 35 much fainter (mostly between R=16
and >21) Hα emitters have been found in the cloud. Their
color-magnitude distribution suggests a median age of about 0.5Myr,
with considerable dispersion. There are also at least five bright
B-type stars in the cloud, presumably of about the same age; none show
the peculiarities expected of HAeBe stars. Dereddened, their apparent
V magnitudes lead to a distance of about 700pc. Radio observations
suggest that the optical object LkHα 101 is in fact a hot star
surrounded by a small H II region, both inside an optically thick dust
shell.
Description:
Optical images behind BVRcIc filters, covering an area of about
7.5'x7.5' centered on LkHα 101, were obtained at the f/10 focus
of the University of Hawaii (UH) 2.2m telescope in 1999 October.
Near-infrared JHK images of NGC 1579 were obtained in 2002 August with
the QUIRC (QUick InfraRed Camera) infrared array at the f/10 focus of
the UH 2.2m telescope. The spectra of LkHα 101 were obtained
with the HIRES spectrograph at the Keck I telescope on three
occasions: 2000 February 2, November 5, and 2002 December 16.
Objects:
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RA (2000) DE Designation(s)
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04 30 14.4 +35 16 24 LKHa 101 = HBC 40
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 90 325 Optical and near-infrared photometry of stars
in NGC 1579
table4.dat 80 9 Coordinates and Lick UBV photometry of bright
stars in L1482
table8.dat 50 219 Emission lines in LkHα 101
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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- 3 I3 --- [HAD2004] Star identified as [HAD2004] NGC 1579 NNN
in Simbad
5 A1 --- f_[HAD2004] Flag on [HAD2004] (1)
7 I1 h RAh Hour of right ascension (J2000)
9- 10 I2 min RAm Minute of right ascension (J2000)
12- 16 F5.2 s RAs Second of right ascension (J2000)
18 A1 --- DE- Sign of the declination (J2000)
19- 20 I2 deg DEd Degree of declination (J2000)
22- 23 I2 arcmin DEm Arcminute of declination (J2000)
25- 28 F4.1 arcsec DEs Arcsecond of declination (J2000)
30- 34 F5.2 mag Vmag ? The V-band magnitude (2)
36- 40 F5.2 mag B-V ? The (B-V) color index (2)
42 A1 --- f_B-V [)] Flag on B-V (3)
44- 47 F4.2 mag V-Rc ? The (V-Rc) color index (2)
49- 52 F4.2 mag V-Ic ? The (V-Ic) color index (2)
54- 58 F5.2 mag Rcmag ? The R-band magnitude (2)
60- 63 F4.2 mag Rc-Ic ? The (Rc-Ic) color index (2)
65- 69 F5.2 mag Jmag ? The J-band magnitude (2)
71- 75 F5.2 mag J-H ? The (J-H) color index (2)
77 A1 --- f_J-H [)] Flag on J-H (3)
79- 82 F4.2 mag H-K ? The (H-K) color index (2)
84- 89 A6 --- SpType MK spectral type
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Note (1): Flag on [HAD2004], defined as follows:
c = Integrated magnitudes of an unresolved binary.
d = Emission lines including [OI](6300, 6363), [NII](6584), and
[SII](6716, 6730) are present.
e = Integrated magnitudes of an unresolved triple.
f = The IR colors of this star are severely affected by the steep
brightness gradient of the LkHα 101 infrared nebulosity; its
J and H magnitudes are particularly uncertain.
g = This is LkHα 101. Two stars are present within the glare of
this star: one to the northeast at RA=4 30 14.76, DE=+35 16 34.5
[J=14.9, (J-H)=1.7, (H-K)=1.0] and one to the southwest at
position0 4 30 13.73 +35 16 20.9 [J=16.1, (J-H)=2.2, (H-K)=1.6].
Because of the glare from LkHα 101, the photometry for these
objects is rather uncertain.
h = This is star D. The spectral type is uncertain, but likely K0 III.
See the text for details.
i = This is a double star and is saturated in V. Therefore, the B
magnitude is flagged with a parenthesis in the (B-V) column.
Note (2): The BVRI colors have been converted to the Johnson-Kron-Cousins
photometric system, whereas the JHK colors are on the new
Mauna Kea filter system.
Note (3): A ")" indicates that only one of the magnitudes in the color is
available.
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Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
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1- 20 A20 --- SName Simbad designation
23 A1 --- n_SName Illuminating star (1)
25 A1 --- f_SName Individual notes (2)
27 I1 h RAh Hour of Right Ascension (J2000)
29- 30 I2 min RAm Minute of Right Ascension (J2000)
32- 35 F4.1 s RAs Second of Right Ascension (J2000)
37 A1 --- DE- Sign of the Declination (J2000)
38- 39 I2 deg DEd Degree of Declination (J2000)
41- 42 I2 arcmin DEm Arcminute of Declination (J2000)
44- 45 I2 arcsec DEs Arcsecond of Declination (J2000)
48- 52 F5.2 mag Vmag V magnitude
55- 58 F4.2 mag B-V B-V color index
61- 64 F4.2 mag U-B ? U-B color index
65 A1 --- u_U-B [:] Uncertainty on U-B
68- 69 A2 --- SpType MK spectral type
70 A1 --- u_SpType [:] Uncertainty on SpType
73- 74 I2 km/s RV ? Radial velocity
75 A1 --- u_RV [:] Uncertainty on RV
78- 80 I3 km/s vsini ? Projected rotational velocity
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Note (1): Those stars that illuminate individual reflection nebulae are marked
with asterisks
Note (2): Flag on ID, defined as follows:
b = HD 279899. It is star A of Barsony et al. (1990ApJ...362..674B 1990ApJ...362..674B). The V,
B-V values in their Table 2 must be in error. It is S222, star 1 of
Hunter & Massey (1990AJ.....99..846H 1990AJ.....99..846H); they classified it as B37 V.
c = This is star B of Barsony et al. (1990ApJ...362..674B 1990ApJ...362..674B), for which they
give V=13.92, B-V=1.34. Our values (Table 1/249) are 13.43, 1.87.
d = The nebulosity at H is IC 2067.
e = Our values (Table 1/40) are V=14.63, B-V=1.06.
f = The V and B-V for LkHα101 are from Table 1. Published values are
15.67, 1.99 from Barsony et al. (1990ApJ...362..674B 1990ApJ...362..674B), and 14.76, 0.90
from Bergner et al. (1995A&AS..112..221B 1995A&AS..112..221B).
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Byte-by-byte Description of file: table8.dat
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Bytes Format Units Label Explanations
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1- 7 F7.2 0.1nm lambdaMean Intensity-weighted mean wavelength of the
line (1)
8 A1 --- u_lambdaMean [:] Uncertainty on lambdaMean
10- 14 A5 --- f_lambdaMean Flag on lambdaMean (2)
16- 20 F5.2 0.1nm EW ? Equivalent width of the entire line, in
angstroms, or lower value if EW exists.
21 A1 --- u_EW [:] Uncertainty on EW
23 I1 0.1nm EWu ? Upper limit of equivalent width when
interval
24 A1 --- u_EWu [:] Uncertainty on EWu
26- 40 A15 --- Ion The likely identification (with RMT number
in parentheses) (3)
42- 49 F8.3 0.1nm lambdaLab ? Laboratory wavelength
50 A1 --- f_lambdaLab [?] Flag on lambdaLab
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Note (1): The intensity-weighted mean wavelength of the line, not the wavelength
of the intensity peak, and not corrected for the stellar velocity.
This mean wavelength will change as the line structure varies.
Note (2): Flag on lambdaMean, defined as follows:
d = double peaks;
t = triple peaks;
br = the line is broad;
bl = the line is blended with another;
as = the line is asymmetric;
1 = the line measured on only one spectrogram, usually because it falls in
an interorder gap on the others;
n1 = Line 5264 has a shortward wing, probably FeII(5264.176);
n2 = Line 5746: the measurements include a shortward wing, possibly
FeII(5746.578);
n3 = Line 6456: the measurements include a distinct subsidiary peak on the
shortward edge at about 6455.69, probably a blend of two weaker FeII
lines, plus a contribution from OI RMT 9;
n4 = Line 6548: The [NII] line is confused by an overlapping atmospheric
H2O line;
n5 = Line 6562: see the text for a discussion of Hα;
n6 = Line 6678 falls in a corner of the frame and possibly for that reason
measurements are discordant;
Note (3): A plus sign means that there is probably another contributor. The
[Fe II] and Fe II wavelengths are from Johansson (1977PhyS...15..183J 1977PhyS...15..183J)
and (1978PhyS...18..217J 1978PhyS...18..217J), respectively.
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History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Marianne Brouty [CDS] 08-Jun-2005