J/A+AS/123/63 NGC 6530 multiwavelength photometry (van den Ancker+ 1997)
A multiwavelength study of star formation in
the very young open cluster NGC 6530
van den Ancker M.E., The P.S., Feinstein A., Vazquez R.A., de Winter D.,
Perez M.R.
<Astron. Astrophys. Suppl. Ser. 123, 63 (1997)>
=1997A&AS..123...63V 1997A&AS..123...63V (SIMBAD/NED BibCode)
ADC_Keywords: Clusters, open ; Photometry
Keywords: circumstellar matter - stars: formation - stars: pre-main sequence -
dust, extinction - H II regions -
open clusters and associations: NGC 6530
Description:
The distance and formation history of the very young open cluster NGC
6530 were investigated by studying a total of 132 probable member
stars of this open cluster. It was concluded that the distance to NGC
6530 is 1.8±0.2kpc, and its interstellar reddening E(B-V) is 0.30.
Furthermore, we conclude that the extinction law of the intracluster
material is normal (i.e. R_V=3.1), but anomalous extinction laws were
found for several more embedded stars in the cluster. Of the 132 stars
included in this study, 11 are suspected to be variable, five show
Halpha in emission and nine show an infrared excess. Among the member
stars of NGC 6530, three were found to be part of the Herbig Ae/Be
stellar class, whereas two others are possible members of this stellar
group as well. Also, one cluster member is probably a new massive
post-AGB star, whereas the same could possibly apply to another member
star. Finally, from the distribution of post- and pre-main sequence
stars in the cluster's HR-diagram, it was concluded that the process
of star formation in NGC 6530 must have started a few times 10^7 years
ago and, for the less massive stars, is probably still going on today.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1 95 132 Properties of programme stars in NGC 6530 from
literature
table2 129 105 New photometric data of stars in NGC 6530
table5 91 130 Astrophysical parameters of stars in NGC 6530
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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- 3 A3 --- VAJ Star number by van Altena & Jones
(1972A&A....20..425V 1972A&A....20..425V)
6- 8 A3 --- Walk Star number by Walker (1957ApJ...125..636W 1957ApJ...125..636W) and
Kilambi (1977MNRAS.178..423K 1977MNRAS.178..423K)
10- 12 A3 --- Sag Star number by Sagar & Joshi (1978MNRAS.184..467S 1978MNRAS.184..467S)
15- 27 A13 --- Other Other designation
29- 30 I2 h RAh Right ascension (J1950)
32- 33 I2 min RAm Right ascension (J1950)
35- 38 F4.1 s RAs Right ascension (J1950)
41 A1 --- DE- Declination sign
42- 43 I2 deg DEd Declination (J1950)
45- 46 I2 arcmin DEm Declination (J1950)
48- 49 I2 arcsec DEs Declination (J1950)
52- 53 I2 % Prob ? Proper motion membership probability
56- 60 F5.2 mag Vmag V magnitude
63- 66 F4.2 mag B-V ? B-V colour index
69- 73 F5.2 mag U-B ? U-B colour index
76- 80 F5.1 km/s HRV ? Heliocentric radial velocity
83- 93 A11 --- Sp Spectral type
95 A1 --- Ref. Reference for spectral type (1)
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Note (1): 1: Buscombe 1984, See Cat. III/189
2: Boggs & Boehm-Vitense (1989ApJ...339..209B 1989ApJ...339..209B)
3: Walker (1957ApJ...125..636W 1957ApJ...125..636W)
4: Johnson & Borgman (1963BAN....17..115J 1963BAN....17..115J)
5: Hiltner et al. (1965ApJ...141..183H 1965ApJ...141..183H)
6: Torres (1987ApJ...322..949T 1987ApJ...322..949T)
7: Boesono et al. (1987Ap&SS.137..167B 1987Ap&SS.137..167B)
8: Morrison & Conti (1978ApJ...224..558M 1978ApJ...224..558M)
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Byte-by-byte Description of file: table2
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Bytes Format Units Label Explanations
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1- 4 A4 --- No. Star number for new stars
6- 11 F6.3 --- Vmag ? Walraven V intensity
14- 18 F5.2 mag Vmag1 ? Johnson V magnitude computed from
Walraven V and V-B
21- 25 F5.3 --- V-B ? Walraven V-B colour index
28- 32 F5.3 --- B-U ? Walraven B-U colour index
34- 39 F6.3 --- U-W ? Walraven U-W colour index
42- 46 F5.3 --- B-L ? Walraven D-L colour index
49- 55 A7 --- Date1 Date (dd/mm/yy) of Walraven measurement
58- 62 F5.2 mag Vmag2 ? Johnson V magnitude
65- 68 F4.2 mag B-V ? Johnson B-V colour index
71- 75 F5.2 mag U-B ? Johnson U-B colour index
78- 81 F4.2 mag V-R ? Cousins V-R colour index
84- 87 F4.2 mag V-I ? Cousins V-I colour index
90- 96 A7 --- Date2 Date (dd/mm/yy) of UBVRI measurement
99-103 F5.2 mag Jmag ? ESO J magnitude index
106-110 F5.2 mag Hmag ? ESO H magnitude index
113-117 F5.2 mag Kmag ? ESO K magnitude index
120-126 A7 --- Date3 Date (dd/mm/yy) of JHK measurement
129 A1 --- Remark [1/2] Remarks (1)
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Note (1): 1: Probably a variable star.
2: Two sources at that position in the infrared.
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Byte-by-byte Description of file: table5
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Bytes Format Units Label Explanations
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1- 4 A4 --- No. Star number
6- 13 A8 --- SpUBVl Spectral type from UBV data from literature
15- 22 A8 --- SpUBVn Spectral type from new UBV data
24- 31 A8 --- SpWalr Spectral type from new Walraven data
33- 37 A5 --- SpIDS Spectral type from IDS spectrum
40- 44 A5 --- SpCCD Spectral type from CCD spectrum
48- 54 A7 --- SpAdop Adopted spectral type
57- 60 F4.2 mag E(B-V) B-V colour excess
63- 65 F3.1 --- Extinct ? Ratio of visual to selective extinction
66 A1 --- u_Extinct Uncertainty flag on extinct
68- 71 F4.2 kpc Dist Photometric distance
74- 78 F5.3 K logTeff log of effective temperature
81- 85 F5.3 solLum logL log of stellar luminosity
88- 91 A4 --- IRexcess Presence of infrared excess (YES/NO)
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Acknowledgements: Mario van den Ancker
References:
van Altena W.F., Jones B.F. 1972, A&A 20, 425 =1972A&A....20..425V 1972A&A....20..425V
Boesono B., The, P.S., Tjin A Djie, H.R.E. 1987, Ap&SS 137, 167
=1987Ap&SS.137..167B 1987Ap&SS.137..167B
Boggs D., Boehm-Vitense E. 1989, ApJ 339, 209 =1989ApJ...339..209B 1989ApJ...339..209B
Buscombe W. 1984, Sixth General Catalogue of MK Spectral Classifications,
Northwestern University, Evanston, Illinois =Catalogue III/189
Hiltner W.A., Morgan W.W., Neff J.S. 1965, ApJ 141, 183
=1965ApJ...141..183H 1965ApJ...141..183H
Johnson H.L., Borgman J. 1963, B.A.N. 17, 115 =1963BAN....17..115J 1963BAN....17..115J
Kilambi G.C. 1977, MNRAS 178, 423 =1977MNRAS.178..423K 1977MNRAS.178..423K
Morrison N.D., Conti P.S. 1978, ApJ 224, 558 =1978ApJ...224..558M 1978ApJ...224..558M
Sagar R., Joshi U.C. 1978, MNRAS 184, 467 =1978MNRAS.184..467S 1978MNRAS.184..467S
Torres A.V. 1987, ApJ 322, 949 =1987ApJ...322..949T 1987ApJ...322..949T
Walker M.F. 1957, ApJ 125, 636 =1957ApJ...125..636W 1957ApJ...125..636W
(End) Patricia Bauer [CDS] 13-Sep-1996