J/A+AS/118/503 Proper motions of stars in Ori Nebula (Tian+ 1996)
Proper motions of stars in the region of the Orion Nebula cluster (C 0532-054)
Tian K.P., van Leeuwen F., Zhao J.L., Su C.G.
<Astron. Astrophys. Suppl. Ser. 118, 503 (1996)>
=1996A&AS..118..503T 1996A&AS..118..503T (SIMBAD/NED BibCode)
ADC_Keywords: Clusters, open ; Proper motions
Keywords: open clusters - C 0532-054 - astrometry
Description:
Relative proper motions and membership probabilities for 333 stars
within an area of 1.6deg by 1.8deg centred on the Orion Nebula M 42
are determined using plates taken over a period of 83 years with the
double astrograph of Shanghai Observatory (scale of 30"/mm). The
plates were measured with the ASTROSCAN automatic plate-measuring
machine of Leiden Observatory. The average proper motion accuracy
obtained for stars in the photographic magnitude range 7 to 14 is
0.3mas/yr. Errors are somewhat larger towards fainter and brighter
magnitude, but the majority lie well below 1mas/yr. 64% of the stars
have been measured successfully on at least 13 out of 18 plates. The
number of stars with membership probabilities higher than 0.7 is 184.
It is shown by a detailed discussion that the proper motions and
membership probabilities of the stars determined in this paper are in
good agreement with the results presented recently by other authors.
Although there is a clear concentration in the proper motion diagram,
both the remaining dispersion of the internal motions and the
distribution of "members" as projected on the sky indicate that the
stars in this region are not bound as one system, but do have a common
origin. A similar conclusion can be drawn from a comparison with
spectroscopic and radial velocity data.
Objects:
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RA (2000) DE Designation(s)
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05 35.4 -05 23 C 0532-054 = M 42 = Ori Nebula
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table3 100 333 Results of the astrometric study
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See also:
II/171 : PARENAGO Catalogue of stars in the area of the Orion Nebula
Byte-by-byte Description of file: table3
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Bytes Format Units Label Explanations
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4- 6 I3 --- No [1/406]+ Sequential number
10- 13 I4 --- Parenago Parenago number (Catalogue II/171)
17- 21 F5.2 mag Pmag Photographic magnitude
25 I1 h RAh Right ascension (J2000, Epoch 1950)
28- 29 I2 min RAm Right ascension (J2000, Epoch 1950)
32- 37 F6.3 s RAs Right ascension (J2000, Epoch 1950)
41 I1 ms e_RAs rms uncertainty on RA
43 A1 --- DE- Declination sign
44 I1 deg DEd Declination (J2000, Epoch 1950)
47- 48 I2 arcmin DEm Declination (J2000, Epoch 1950)
51- 55 F5.2 arcsec DEs Declination (J2000, Epoch 1950)
58- 59 I2 mas e_DEs rms uncertainty on DE
62- 66 F5.1 mas/yr pmRA Proper motion along RA
69- 71 F3.1 mas/yr e_pmRA rms uncertainty on proper motion RA
74- 78 F5.1 mas/yr pmDE Proper motion in DE
81- 83 F3.1 mas/yr e_pmDE rms uncertainty on proper motion DE
87- 88 I2 --- Plate Number of plates used
91- 95 F5.1 yr Ep-1950 Mean epoch in years, relative to 1950.0
99-100 I2 % Memb Membership probability in percents
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References:
Parenago, P.P. 1954, Trudy Sternberg Astron.Inst. Vol.25 =Catalogue II/171
(End) Patricia Bauer [CDS] 06-May-1996