The bright star, left and above center, is known as Alpha Cam. The star was thought to have possibly once been part of a binary star system. One theory suggests that the partner star exploded and propelled Alpha Cam, an O class star, at a high velocity right into a thick cloud of dust and hydrogen gas. Another theory is that gravitational encounters during cluster formation propel the star outward. As you can see in this image, the motion of the star has created "bow shock", spreading the gas and dust out in front of it. This is similar to the effect a speedboat has to the water as it plows through at high speed. The gas and dust in the bow shock and large wake around the star (see the wide-field images in H-a light below) cover a large area of space. This is due in part to the fact that Alpha Cam is a rare blue-white supergiant with a mass estimated at some 25-30 suns. The star is tremendously luminous and would be one of the brightest stars in our sky if it were not obscured by so much intervening gas and dust. Estimates are that Alpha Cam is between 500,000 and 1 million times as luminous as the sun!! Distance estimates vary and indications are that the star is around 6,300 light years distant.
Image Data: H-a, 15 minutes x 12: RGB, 15 minutes x 6 each: Epsilon 180: SBIG STL 6303: AstroDon filters: shot from New Mexico Skies
The arrow indicates Alpha Cam in the inverted H-a image.
An inverted Hydrogen-alpha image shows the extent and detail of the Alpha Cam interaction with surrounding gas and dust.
Image Data: 15 minutes x 16 exposures: SBIG STL 6303: AstroDon 6nm H-a filter: Canon 300mm f/2.8 from Hidden Valley Observatory
Alpha Cam was imaged by IRAS and the cold dust was captured in this image. The faint blue star directly below the arc of dust is Alpha Cam.