GSH 057+12-077

Right Ascension (hh mm): 18 50
Declination (deg): 26.50
Reference Velocity (km/s): -77.26
Delta RA (hh mm): 00 07
Delta Dec (deg): 1.25
Delta V (km/s): 12.38
Mean Angular Diameter (deg): 1.10
Shape parameter: 0.85
Comments:

Kinematic Distances Information
    Kinematic Distance (kpc): 19
    Allowed Range (kpc): 18 to 20
    Only one kinematic distance solution found for this radial velocity
Inferred Shell Size
    Shell Diameter (pc): 360
    Allowed Range (pc): 350 to 380
Distance Notes:
       Not clear if shell is associated with local or Galactic gas. Kinematic distances could well be inaccurate.
       Inferred shell size plausible in context of extent of Galactic Plane

Expansion Velocity Information
    Velocity of Back Wall V_b (km/s): -53
        Clear maximum on one side, but no clear minimum in spectrum
    Minimum 'Shell-like' velocity V₁ (km/s): -80
    Maximum 'Shell-like' velocity V₂ (km/s): -68
    Lower Limit on V_exp (km/s): 14 (from V₁ and V_b)
        At least one spectral maximum is broad and/or peaks at a velocity close to the last shell-like velocity, so expansion velocity limit might be underestimated.