The Tulip Nebula is an area of gas excited by a type O6.5 star, HD 227018, and some other type O stars nearby. HD 227018 is the blue-white star just right of the nebula's center, the one that shows a bow-shock. It's not the brightest star visually, but it's the hottest star, and its UV light ionizes the local hydrogen, making it glow. It's the instigator of most of the glow you see here.
Notice that the blue star at the upper left has two sets of horizontal diffraction spikes. It's a double star! That's why.
This is two-color image, H-alpha (9x1800") and O-III (7x1800"), with a synthetic green channel constructed of the two colors. I plan to collect SII when I can, to make a Hubble palette version. The telescope was the Synta-ONTC 203mm f/4.95 Newtonian with Baader MPCC and the SXVF-H9 through Astronomik filters.
