Showing posts with label HH 890. Show all posts
Showing posts with label HH 890. Show all posts

February 9, 2013

NGC 2244 & the Rosette Nebula Center, Bi-Color (Dec. & Jan, 2012-13)

Here is my recent NGC 2244 and Rosette data arranged as a bi-color.  In this rendition, I have mixed the Ha [+NII] data with SII at a 2:1 ratio.  These wavelengths, which fall in the red part of the spectrum, became Red.  Blue in this image comprises OIII and Ha data mixed at 4:1, and Green comprises OIII and SII data mixed at 4:1.  The color strengths were adjusted after combination to emphasize the difference between red and blue, so the contrast visible here is between Ha, NII, and SII, on the one hand, and OIII on the other, red v. blue-green.  Capture data for this image appears in the Hubble palette post for this object, dated February 4, 2013.  The telescope used was the AT111EDT, the camera the SXVF-H9.

February 4, 2013

NGC 2244 and the Rosette Nebula Center (Dec. & Jan. 2012-13)

This is the center of the Rosette Nebula, a fascinating place.  The squall line of dust and gas clouds in the upper left (northwest) is being slowing washed away by stellar winds from the brilliant O stars in the cluster NGC 2244, which occupies the middle of the image.  In fact, the cluster has blown a hole in the middle of the cloud, which is why the background in the middle of the image is dimmer than the surrounding sky.  And the loops and filaments throughout the image add intrigue and color.  Also, notice some stars here appear distinctly yellow.  In this color scheme, those stars glow far more brightly in ionized sulphur than in ionized hydrogen or oxygen, and that in itself is a cool fact.

The Rosette is also famous for harboring Herbig-Haro objects.  The most famous of these is just to the left (north) of the brightest star in my image, and faintly visible, but more visible in this brightened and more contrasty cut from the Ha [+NII] image:
My image is processed roughly in the Hubble palette, which means green for Ha, blue for OIII, and red for SII.  I've modified the weighting of the colors slightly to boost contrast and (I hope) aesthetics.

Telescope: Astro-Tech AT111EDT and William Optics P-FLAT4 (eff. at f/5.6)
Camera and Exposure: SXVF-H9C; Ha [+NII] 10x15', OIII 11x20', SII 12x20'; Alnitak Flat-man flats
Filter: Astronomik 12nm narrowband filters
Guiding: SX Lodestar and SX OAG
Mount: Takahashi NJP
Software: Nebulosity, Maxim DL, Registar, Photoshop CS3
Location: The Woodlands, TX