J/AZh/87/853 Stellar groups of Orion's Sword region (Vereshchangin+, 2010)
Stellar groups and clusters in the region of Orion's Sword.
Vereshchangin S.V., Chupina N.V.
<Astron. Zh. 87, 853 (2010)>
=2010AZh....87..853V 2010AZh....87..853V
=2010ARep...54..784V 2010ARep...54..784V
ADC_Keywords: Nebulae ; Proper motions
Abstract:
The region of Orion's Sword with coordinates RA=83.79°,
DE=-5.20° and a size of 1.0°x2.5° is analyzed. We
compiled a master catalog of stars observed in the optical, containing
positions, proper motions, and UBV photometry for 1634 stars. Using
the nearest-neighbor-distance technique, we subdivided the region into
stellar groups with different numbers of members. The positions of
five groups coincide with known clusters, and two groups coincide with
aggregates of stars with Hα emission. We have identified groups
with low membership that are moving away from the system. We also
considered the kinematic structure of the groups using the AD-diagram
method we developed earlier. Most of the stellar clusters and groups
display similar kinematics, with the exception of the group OMC-2,
which is moving toward its own apex. We also confirmed the existence of
the kinematic star group 189 discovered earlier; its position is close
to the cluster NGC 1977, and it is probably a component of its corona.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 146 73 Stellar groups identified in the Orion's Sword region
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See also:
J/AZh/88/143 : ORICAT, Stars in Orion Great Nebula (Vereshchagin+, 2011)
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 9 A9 --- Group Group name (1)
11- 15 I5 --- Oricat Oricat number, Cat. J/AZh/88/143
18- 22 I5 --- HIP ? HIP number
24- 33 A10 --- SpType MK spectral type
35- 39 F5.2 mag Bmag B magnitude
41- 45 F5.2 mag B-V ? B-V colour index
47- 50 F4.1 mas/yr pmx ? Proper motion along X
52- 55 F4.1 mas/yr pmy ? Proper motion along Y
57- 59 F3.1 mas/yr e_pmx ? rms uncertainty on pmx
61- 63 F3.1 mas/yr e_pmy ? rms uncertainty on pmy
65- 66 I2 % PT ? Membership Probability according to
Tian et al. (1996, Cat. J/A+AS/118/503)
68- 69 I2 % PM ? Membership Probability according to
McNamara et al., 1989AJ.....97.1427M 1989AJ.....97.1427M
71-146 A76 --- Notes Notes
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Note (1): Main data for clusters in the Orion's Sword region
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Name(s) RA DE RV d r
deg deg km/s arcmin pc
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NGC 1981 Upper Sword Walker 1 83.79 -4.42 28 28 400
NGC 1977 Walker 2 83.83 -4.82 25 25 500
OMC-2 Walker 3 83.79 -5.15
Trapezium NGC 1976 Walker 4 83.84 -5.37 23 48 450
NGC 1980 Lower Sword Walker 5 83.84 -5.92 21 14 550
Group D 83.75 -5.73
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Group 189 (in the stellar region occupied by NGC 1977)
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 27-Sep-2010