NGC 7027
Some new data for this nebula went public yesterday, and... it's different. The observations were almost all narrowband emission lines, and there were a lot of them. Five visible, four near-infrared, two wideband near-infrared. For this image I used only the visible filters. It turned out quite colorful, and quite unlike all the Hubble imagery that came before it. [O III] really wants to dominate the image, but I toned it down quite a bit with a technique I only use rarely, which is to group filters by the similarity the reveal within the object rather than trying to merge all filters into a single image.
If you would like to see the old image of this nebula, check here: flic.kr/p/fC7DwR
I was interested to see if any more structures were revealed especially in the near-infrared data, like the double rings (it's questionable they are really rings), but it's not nearly as apparent in these data as it was back in the old NICMOS data. The double rings, if that's what they are, are most pronounced in F212N, which is a molecular hydrogen filter. None of the filters for this image reveal quite the same structure that the F212N filter did.
The nebula expanded quite a bit in the two decades since the previous HST observations were taken. In terms of this image, the maximum movement amounted to around 8 pixels at WFC3/UVIS resolution (100% zoom of this image). All of the stars moved around, too. The new image is slightly higher resolution, but not much.
Explaining the processing further, I took the F673N, F487N, & F343N filters to make a 3-color image. I chose these because none of them was overwhelmingly brighter in any area than the other, but they all do still reveal delicate color separation. Next, I combined the F656N and F502N filters into a 2-color image. The signal for these two filters was much more intense, and they worked nicely together to reveal the fainter structures of the nebula, especially those faint shells emanating gently outward from the nebula in nearly circular formation. The 2-color combination is not especially colorful though, so I used it as a luminosity layer. Stars are always funky in narrowband imagery, so I removed all the stars from the 3-color image, leaving the 2-color luminosity layer to show them.
Data from the following proposal were used to create this image:
Luminosity:
WFC3/UVIS F656N + WFC3/UVIS F502N
Color:
Red: WFC3/UVIS F673N
Green: WFC3/UVIS F487N
Blue: WFC3/UVIS F343N
North is up.
NGC 7027
Some new data for this nebula went public yesterday, and... it's different. The observations were almost all narrowband emission lines, and there were a lot of them. Five visible, four near-infrared, two wideband near-infrared. For this image I used only the visible filters. It turned out quite colorful, and quite unlike all the Hubble imagery that came before it. [O III] really wants to dominate the image, but I toned it down quite a bit with a technique I only use rarely, which is to group filters by the similarity the reveal within the object rather than trying to merge all filters into a single image.
If you would like to see the old image of this nebula, check here: flic.kr/p/fC7DwR
I was interested to see if any more structures were revealed especially in the near-infrared data, like the double rings (it's questionable they are really rings), but it's not nearly as apparent in these data as it was back in the old NICMOS data. The double rings, if that's what they are, are most pronounced in F212N, which is a molecular hydrogen filter. None of the filters for this image reveal quite the same structure that the F212N filter did.
The nebula expanded quite a bit in the two decades since the previous HST observations were taken. In terms of this image, the maximum movement amounted to around 8 pixels at WFC3/UVIS resolution (100% zoom of this image). All of the stars moved around, too. The new image is slightly higher resolution, but not much.
Explaining the processing further, I took the F673N, F487N, & F343N filters to make a 3-color image. I chose these because none of them was overwhelmingly brighter in any area than the other, but they all do still reveal delicate color separation. Next, I combined the F656N and F502N filters into a 2-color image. The signal for these two filters was much more intense, and they worked nicely together to reveal the fainter structures of the nebula, especially those faint shells emanating gently outward from the nebula in nearly circular formation. The 2-color combination is not especially colorful though, so I used it as a luminosity layer. Stars are always funky in narrowband imagery, so I removed all the stars from the 3-color image, leaving the 2-color luminosity layer to show them.
Data from the following proposal were used to create this image:
Luminosity:
WFC3/UVIS F656N + WFC3/UVIS F502N
Color:
Red: WFC3/UVIS F673N
Green: WFC3/UVIS F487N
Blue: WFC3/UVIS F343N
North is up.