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NGC 6809 (M 55)

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Distance from Sun: 5350 ± 50 pc Galactocentric distance: 4010 ± 30 pc V-band magnitude: 6.29 ± 0.03 Mass: 1.97 · 105 M☉ M/L ratio: 2.1 ± 0.1 M☉/L☉ Half-mass radius: 6.78 pc Power-law MF slope: α = -0.93 ± 0.13

Image Credit: Bernhard Hubl, http://www.astrophoton.com/

Observations
Cluster distance	Proper motion	Radial velocity
Orbit over the last 500 Myr
Velocity dispersion profile	Rotation	Color magnitude diagram
HST photometry	Mass function	MF slope
N-body Fits
Surface density	Proper motions	Radial velocities
Remnant fraction	Mass-to-light ratio