J/AJ/117/1375 Orion Trapezium cluster (Simon+, 1999)
Adaptive optics imaging of the Orion Trapezium cluster.
Simon M., Close L.M., Beck T.L.
<Astron. J. 117, 1375 (1999)>
=1999AJ....117.1375S 1999AJ....117.1375S
ADC_Keywords: Clusters, open ; Stars, double and multiple ; Photometry
Keywords: binaries: visual - stars: pre-main-sequence -
techniques: image processing
Abstract:
We have imaged an area ∼5arcmin2 at the center of the Trapezium
cluster in Orion in the K band using the University of Hawaii (UH)
adaptive optics system at the UH 2.2 m telescope. Our survey detects
292 stars brighter than K=18.2mag and resolves pairs to the 0.23"
diffraction limit of the telescope. The binary fraction in the angular
separation range 0.3"-0.6", corresponding to 132-264AU at 440pc, is
indistinguishable from that of the solar-like stars in the solar
neighborhood. Proplyds are associated with both single stars and
visual binaries. About half the stars in our sample have also been
measured at V and I by Prosser et al. (1994ApJ...421..517P 1994ApJ...421..517P); most of
these seem to be about 106yr old, observed through moderate
extinction, and having some excess emission at K. The luminosity
function turns over before the stellar limit of ∼13.5mag, indicating
that the cluster does not contain a large population of massive brown
dwarfs.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 78 292 Detected stars in the Trapezium cluster
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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 --- [SCB99] Sequential number
5- 8 I4 pix xpos x position
10- 13 I4 pix ypos y position
15- 16 I2 h RAh Right ascension (J2000.0)
18- 19 I2 min RAm Right ascension (J2000.0)
21- 26 F6.3 s RAs Right ascension (J2000.0)
28 A1 --- DE- Declination sign (J2000.0)
29- 30 I2 deg DEd Declination (J2000.0)
32- 33 I2 arcmin DEm Declination (J2000.0)
35- 39 F5.2 arcsec DEs Declination (J2000.0)
41- 45 F5.2 mag Kmag ?=0 K magnitude
47- 51 F5.2 mag Vmag ?=0 V magnitude
53- 57 F5.2 mag Imag ?=0 I magnitude
59- 61 I3 --- PSH Prosser et al. (1994ApJ...421..517P 1994ApJ...421..517P)
identification number
63- 65 I3 --- TCC McCaughrean et al. (1994AJ....108.1382M 1994AJ....108.1382M)
identification number
67- 78 A12 --- Name Other name
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History: From AJ electronic version
(End) James Marcout, Patricia Bauer [CDS] 27-May-1999