Cygnus X Subcluster Classifier

Enter a position and proper motion in either Equatorial (ICRS) or Galactic coordinates. Parallax and parallax error are optional, but they must be supplied together.

Coordinate system
Astrometric data

Position

Proper motion

Parallax

Required: position and proper motion. Optional: parallax and parallax error, entered as a pair. A supplied parallax error must be greater than zero.

Cygnus X clusters and associations

Summary of cluster coordinates and mean astrometry
Label Coordinates Nmem GMM # Mean Gaia astrometry vlsrk†
ℓ0 b0 Δℓ* Δb μℓ*,0 μb,0 ϖ0 d
(deg) (deg) (deg) (deg) (stars) (mas yr-1) (mas yr-1) (mas) (pc) (km s-1)
Near groups
NGC 6914 80.04 +2.70 0.36 0.26 42 14 -6.51 -1.51 1.075 ± 0.020 930 5.0 ± 0.3
BD+40° 4124 78.57 +2.65 1.06 0.88 137 7B, 11 -6.30 -1.27 1.023 ± 0.017 980 7.7 ± 0.4
DR 15 79.33 +0.35 0.57 0.97 72 9B -4.29 -0.78 1.119 ± 0.089 890 1.0 ± 0.3
IRAS 20231+3901 77.41 +0.81 1.31 0.79 62 13 -3.97 -0.77 1.055 ± 0.030 950 2.3 ± 0.3
LDN 896 79.97 -1.49 1.23 0.36 33 17 -3.52 -0.59 1.118 ± 0.036 894 -2.1 ± 0.4
Far groups
Cyg OB2 80.07 +0.76 1.06 1.21 464 2 -5.17 -0.45 0.625 ± 0.006 1600 6.8 ± 0.3
Cyg X North 81.51 +0.62 1.57 2.59 272 5A -4.46 -0.10 0.703 ± 0.011 1420 5.7 ± 4.0
Cyg X South 77.72 +1.12 2.89 3.31 969 3, 6, 7A, 8 -5.55 -0.49 0.593 ± 0.007 1690 -1.6 ± 3.5
IC 1318a 78.98 +3.65 0.24 0.26 84 10 -5.71 0.76 0.561 ± 0.025 1790 -2.9 ± 3.4
Cyg X G82.3+0.8 82.33 +0.76 0.31 0.59 41 15 -4.86 -0.24 0.675 ± 0.017 1480 9.5 ± 1.5
Cyg X G79.1+0.9 79.09 +0.90 0.31 0.73 46 9A -4.88 -1.18 0.534 ± 0.035 1870 7.4 ± 0.3

Columns 1–3: Region name and group centre, defined by the median Galactic longitude ℓ and latitude b of the members. Columns 4–5: Widths encompassing 90% of group members, where Δℓ* ≡ Δℓ cos b; the intervals need not be centred on ℓ0 and b0. Column 6: Number of classified YSO members. Column 7: Contributing GMM components. Columns 8–10: Mean Gaia DR3 astrometry, with statistical uncertainties only. Column 11: Estimated distance.

The table excludes GMM component 5B, which contains a small number of stars on the periphery of IC 5070, mostly outside the Cygnus X field. Other omitted GMM components were excluded as probable non-members or merged into the listed groups.

† Velocities are in the kinematic Local Standard of Rest (LSRK) frame, defined as moving at 20 km s-1 toward (α, δ) = (18h, +30°), B1900, relative to the Solar System barycentre.