Selected as The Universe Today’s Astronomy Picture of the Week, April 7, 2008. Click here for details.
Selected for Astronomy Magazine’s Reader Gallery, October, 2008, full page, page 94
Many images of NGC 6188 are wide-field, such as John Gleason’s remarkable H-a image. My image is a clsoe up of an interesting region of the prominent dust- lane structure. It resembles the "Wall" in NGC7000 in the northern hemisphere. This southern Milky Way structure is 4000 light years distant. The image represents a 45 arcmin square field.
The Hubble palette was used where B= OIII, G = H-a and R= SII in order of increasing wavelength.
5 nm H-a and SII, and 3 nm Astrodon OIII filters were used, along with Astrodon E-Series RGB filters. This is a hydbrid image, mixing both mapped narrowband color and conventional RGB color. Exposures were 20 min. for the narrowband filters and 2 min for the R,G,B filters. The U16M was operated at -20C relative.
