Explanation: An interstellar expanse of glowing gas and obscuring dust presents a bird-like visage to astronomers from planet Earth, suggesting its popular moniker, the Seagull Nebula . This broadband portrait of the cosmic bird covers a 3.5-degree wide swath across the plane of the Milky Way, in the direction of Sirius , alpha star of the constellation of the Big Dog ( Canis Major ). The bright head of the Seagull Nebula is cataloged as IC 2177, a compact, dusty emission and reflection nebula with embedded massive star HD 53367. The larger emission region , encompassing objects with other catalog designations, is Likely part of an extensive shell structure swept up by successive supernova explosions. The notable bluish arc below and right of center is a bow shock from runaway star FN Canis Majoris . Dominated by the reddish glow of atomic hydrogen, this complex of interstellar gas and dust clouds with other stars of the Canis Majoris OB1 association spans over 200 light-years at the Seagull Nebula's estimated 3,800 light-year distance.