ASTRO:
     type=Herbig-Haro object w Shocked Gas element
     const=Orion
     mag=(unk)
     dist=1500 ly
     size=3 ly
IMAGE:
     location=Emerald Bay community, Lake Palestine, TX
     BrtlCls=4
     moon=0% (New Moon)
     exposure=CMOS OSC 73x300s (6.1h)
     palette="HOO"
EQUIPMENT:
​     optics=ES102CF APO / Hyperion 24mmEP (afocal) 1.7x, FL(eff.)=1238mm, f(eff.)/12.1
     camera=ZWO ASI2600MC-Pro
     filter=Optolong L-eXtreme DNB
     mount=Celestron AVX EQ
     guiding= Orion 60x240mm, ZWO ASI244MC
SOFTWARE:
     acquisition=Stellarium, NINA, PHD2
     processing=PixInsight (RCAstro, SetiAstro), Photoshop (Lumenzia, WebSharp-Pro), LrC

HH 222, is not very widely known by the common name "Waterfall Nebula".  Located inside a slightly larger cloud complex better known as, "Orion Streamers", the Waterfall is a prominent Herbig–Haro object.  Together with the Streamers, these beautiful structures are located in the much larger Orion molecular cloud complex.  It is formed by ionized gas streams interacting with surrounding molecular clouds.

Herbig–Haro (HH) objects are bright patches of nebulosity associated with newborn stars.  They are formed when narrow jets of partially ionized gas collide with nearby clouds of gas and dust at several hundred kilometers per second.

HH 222 is a giant, curved filament of shocked gas, stretching in a path with a sinuous pattern that evokes the appearance of an elongated cascading waterfall.  Belying the appearance of downward flow, the actual motion of the object is upward and to the right.   ...by forcing one's attention 'upstream' the structure converges toward a bright, non-thermal radio source in its upper left region.  Fainter parallel streams there enhance the waterfall illusion.  Spectroscopic analysis reveals high-velocity outflows, indicative of bow-shock fronts where material reaches speeds of hundreds of km/s.  The nebula is embedded in a dusty environment within the surrounding cloud structures which, at optical wavelengths, obscure parts of its extents.  However, scientists have used infrared and radio observations to map its full morphology and kinematics.  The structure is appx 3 ly long; ...small by astronomical standards; but it would take somewhere around 3,000 of our Solar Systems lined-up to span its length.

HH 222 is classified as a giant Herbig–Haro flow, arising from collimated outflows ejected by young, low-mass stars during their protostellar phase.  Detailed studies in 2013 identified its origin in the quadruple star system V380 Orionis, a multiple system of young stars located downward and outside this field of view, appx 0.9 ly from the nebula's head.  (See 241230 NGC1999 13th Pearl nebula for a more expansive view and astronomical heritage.)

IMAGER'S COMMENTS: 
"Managed to get a couple more hours in on the "Waterfall" this week. The improvement in detail and overall contrast was very surprising; so, backed-out on the field-of-view a little to present more of the "Orion Streamers" cloud complex; ...then took down the earlier post in favor of this one.  This is a great area to image. It lies inside the actual constellation of Orion, "below" the extremely popular Orion Nebula.  The Orion Constellation has so many interesting and photogenic objects in it, it's hard to go elsewhere in the sky right now."

From an Imager's perspective, this area of the Orion constellation provides a very beautiful and structured starscape; worthy of the effort required to capture its faint details.  It confirms that Orion holds one of the most densely populated, picturesque, and diverse collections of objects to capture in all of the Northern Hemisphere's skies.

260215 - HH222 "Waterfall" nebula, part of "Orion Streamers" cloud complex