ASTRO:
     type=Emission Nebula
     const=Monoceros
     mag=15.2
     dist=3700 ly
     size=100 ly
IMAGE:
     location=EB Driveway
     BrtlCls=4
     moon=1% WxCr
     exposure=DSLR OSC: 39x300s (3.3h), ISO1600
EQUIPMENT:
​     optics=ES102CF APO / Stellarvue 0.8x rdcr, FL(eff.)=571mm, f(eff.)/5.6
     camera=Nikon D90 (mod)
     filter=STC Astro Duo-NB clip-in
     mount=Celestron AVX
     guiding=Orion 60x240mm, ZWO ASi224MC
SOFTWARE:
     acquisition=APT, PHD2, Stellarium
     processing=DSS, Photoshop (RCAstro), LrC
OTHER:
     false L added to simulate LRGB
     Blue channel curve-stretched to bring color forward

IC 2177 is a region of nebulosity that lies along the border between the constellations Monoceros and Canis Major.  It is a roughly circular H-II region centered on the star HD 53367 (visible as the 'eye' of the nebula).  It is also only appx 11 arc-degrees south of the celestial equator, making it visible throughout most of the world.

This nebula was discovered in 1885 by Welsh amateur astronomer Isaac Roberts who described the 'head' region as "pretty bright, extremely large, irregularly round, [and] very diffuse."  The name Seagull Nebula is sometimes applied by amateur astronomers, although that description more properly includes the neighboring regions of star clusters, gas & dust clouds and reflection nebulae depicted here as the 'wings' of the space creature.  This larger region includes the open clusters NGC 2335 (visible in this image at the top of the left 'wing') and NGC 2343 (just to the left of the 'tail').

The nebula lies appx 3700 light years from us here on Earth.  At that distance, its 'wingspan' is calculated to be appx 240 light-years across, making it one of the larger regions of nebulosity visible to us..

Astronomers list the stars clustered near what appears as the seagull's eye as NGC 2327.  This cluster of stars was born about 1.5 million years ago.  The single star in the eye is the brightest and hottest of the newborn stars in the entire nebula, and is responsible for being the strongest source heating up the gas & dust so that it glows in infrared light.

In the image above, you may notice a small, prominent bluish arc over a star in the lower right 'wing' of the caricature.  This is a bow shock from runaway star FN Canis Majoris, (the bright star in the center).  This star is actually a binary star system located in the southern Canis Major constellation, near its northern border with Monoceros.  The binary is dimly visible as a single star to the naked eye with a combined apparent visual magnitude of 5.41.  The system is located at a distance of approximately 3,000 light years away; or, about 700 ly closer to us than the nebula.  Based on parallax viewing from here on Earth, it is drifting away from us with a radial velocity of appx 31 km/s.  It is a runaway star (meaning, it is NOT part of a cluster).  It is associated with the nebula only because of its line-of-sight proximity.  The primary star of the pair is a massive star with estimates ranging from 19 to 36 times the mass of our Sun, and with luminosity estimates of 122,000 to 690,000 times that of our Sun.  The magnitude 7.04 companion star is located at an angular separation of 0.60 arc-seconds from the primary.  It may be barely seen by first enlarging, and then zooming-in on the image.  The prominent and conspicuous bow-shock feature of this star is caused by the powerful stellar winds of this binary pair encountering the nebula cloud as they pass-by each other in space. 

The Seagull nebula is a strikingly beautiful and popular object for amateur astrophotographers to capture.  Both the bow shock wave and the binary star pair are moderately difficult, but desirable details that photographers often aspire to capture as they seek to develop their craft.

210113 - IC2177 "Sea Gull" nebula