Nebulae
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Vela X-1 Bowshock
Some 6000 light years away resides an unusual star system, graced by a parabolic shaped filament of glowing red Hydrogen emission. This is an example of a near perfectly shaped bowshock, created by a runaway star system speeding through space. The system is an eclipsing high-mass X-ray binary (HMXB), composed of the bright OB supergiant star HD77581 and the neutron star Vela X-1; its optically invisible companion.
Measurements have shown that the runaway HMXB system is moving through space at a very high speed of 90 km/sec. As the system moves with supersonic speed through the interstellar medium its stellar wind creates shock-excited emission in the surrounding gas, producing the glowing bowshock in front of it.
The proper motion of the HMXB has been extrapolated back to an origin in the Vel OB1 association some 2.5 million years ago, which also corresponds well with the time of the supernova explosion that induced the natal kick velocity to the Vela X-1 neutron star.
The beautiful diffuse red glow filling the entire frame is foreground emission from the unrelated large Vela Supernova Remnant, which extends far beyond this field of view.
Image details:
Date: 26th February and 5th April 2018
Exposure: HaRGB: 360:20:20:20 mins, total 7 hours @ -25C
Telescope: Homebuilt 12.5" f/4 Serrurier Truss Newtonian
Camera: QSI 683wsg with Lodestar guider
Filters: Astrodon 3nm Ha and LRGB E-Series Gen 2
Taken from my observatory in Auckland, New Zealand
