Placidus
28-05-2016, 01:01 PM
We previously mentioned that Gum 41, an HII region on the outskirts of the Running Chicken near Lambda Centauri, had precious little OIII but, unexpectedly, some SII.
A pleasing image in Hubble Palette with H-alpha mapped to green proved difficult, with intensely violet stars that were resistant to persuasion.
Here we present Gum 41 with H-alpha mapped to red, SII mapped to green, and what may be OIII but is perhaps just reflection nebulosity mapped to blue. We've cropped the field to approx 23 min arc, as there's not much interesting in OIII or SII apart from the central bright region.
Original image here (www.photos.smugmug.com/Category/Star-Forming-Regions/i-WF9Xsww/0/O/Gum%2041%20R%20Ha%204%2C%20G%20SII% 205%2C%20B%20OIII%209hrs.jpg)
The H-alpha was taken at first quarter, but the OIII and SII were taken under full moon, under annoyingly good 1.5 sec arc seeing. Sadly, there was nothing much to see! (There is a song about that).
We think that this is still an interesting image, despite the need for a sharp eye to find the OIII. It is certainly a warning not to try it at home.
H-alpha 4 hrs, OIII 9 hrs, SII 6hrs, in 1hr subs. Astrodon 3nM filters. Aspen CG16M on 20" PlaneWave.
A pleasing image in Hubble Palette with H-alpha mapped to green proved difficult, with intensely violet stars that were resistant to persuasion.
Here we present Gum 41 with H-alpha mapped to red, SII mapped to green, and what may be OIII but is perhaps just reflection nebulosity mapped to blue. We've cropped the field to approx 23 min arc, as there's not much interesting in OIII or SII apart from the central bright region.
Original image here (www.photos.smugmug.com/Category/Star-Forming-Regions/i-WF9Xsww/0/O/Gum%2041%20R%20Ha%204%2C%20G%20SII% 205%2C%20B%20OIII%209hrs.jpg)
The H-alpha was taken at first quarter, but the OIII and SII were taken under full moon, under annoyingly good 1.5 sec arc seeing. Sadly, there was nothing much to see! (There is a song about that).
We think that this is still an interesting image, despite the need for a sharp eye to find the OIII. It is certainly a warning not to try it at home.
H-alpha 4 hrs, OIII 9 hrs, SII 6hrs, in 1hr subs. Astrodon 3nM filters. Aspen CG16M on 20" PlaneWave.