J/PASP/98/1133 The open cluster NGC 346 (Niemela+, 1986)
The young open cluster NGC 346 in the Small Magellanic Cloud
NIEMELA V.S., MARRACO H.G, CABANNE M.L.
<Publ. Astron. Soc. Pac. 98, 1133 (1986)>
=1986PASP...98.1133N 1986PASP...98.1133N (SIMBAD/NED Reference)
ADC_Keywords: Magellanic Clouds; Clusters, open; Photometry, CCD
Keywords: open cluster - CCD photometry - radial velocities - O-type stars
Abstract:
We present CCD photometry and spectrographic observations for stars
in the open cluster NGC 346, which excites the largest H II region
in the Small Magellanic Cloud. These observations show that NGC 346
is an extremely young cluster, containing more than 20 hot O-type
stars. A radial-velocity study of the brightest stars, and also of
the nearby supergiant Of star Sk 80, discloses atmospheric expansion
due to strong stellar winds, but no large-amplitude radial-velocity
variations due to short-period binary motion. However, two stars
are probably longer period binaries.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1 31 58 NGC 346 VRI (Kron-Cousins) CCD photometry
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Byte-by-byte Description of file: table1
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Bytes Format Units Label Explanations
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1- 2 I2 --- Id Star number
9- 13 F5.2 mag Vmag V magnitude
16- 20 F5.2 mag V-R V-R colour index
23- 27 F5.2 mag V-I V-I colour index
31 I1 --- Rem [1-6]? Remarks (1)
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Note (1): 1: integrated magnitude of a double star, not in Figure 3 and 4.
2: data correspond only to the brightest member of the group.
3: V observation affected by a cosmic ray, not in Figures 3 and 4.
4: red star, not in Figure 4.
5: integrated magnitude of a double star.
6: probably non-member, far from cluster center, not in Figure 4.
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Table2 : Spectral classification and absolute magnitudes of the
brightest stars in NGC 346
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Star Spectral Source Mv Remarks
Type
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25 O8.5 III a,c -6.6 No. 2 in a
26 O4 III(f) a -7.1 No. 1 in a
28 O5-6: V: c -5.4 Only 1 weak spectrum
29 O3 III(f) b,c -6.1 No. 3 in b
30 O5-6 V b,c -5.9 No. 4 in b
32 O4-5 V c -5.5
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a: Walborn N.R., 1978, Ap.J. (Letters), 224, L133
b: Walborn N. R. and Blades J.C., 1986, Ap.J. (Letters), 304, L17
c: This study.
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Historical Notes: Keupunched at CDS
(End) Marie-Jose Wagner, Patricia Bauer [CDS] 02-Mar-1995