Starship Asterisk*

bystander wrote: ↑Mon Apr 10, 2023 8:22 pm

APOD Robot wrote: ↑Mon Apr 10, 2023 4:07 am Explanation: ... The featured image ...

looks like a gaseous nebula where star formation takes place. Cataloged as IC 2944, the Running Chicken Nebula spans about 100 light years and lies about 6,000 light years away toward the constellation of the Centaur (Centaurus). The star cluster Collinder 249 is visible embedded in the nebula's glowing gas. Although difficult to discern here, several dark molecular clouds with distinct shapes can be found inside the nebula. These clouds can be more readily seen in the narrower field of view SHO picture. Known as Bok globules, these are dark clouds of dense cosmic dust and gas in which star formation sometimes takes place.

bystander wrote: ↑Mon Apr 10, 2023 8:22 pm

Chris Peterson wrote: ↑Mon Apr 10, 2023 1:44 pm I don't know if they're scientifically assigned or not. My objection is that there is no information about this image to be found, so it's essentially useless for anything other than admiring pretty colors. Not an image that should be accepted for APOD, IMO.

AVAO wrote: ↑Mon Apr 10, 2023 8:15 pm The author describes it as a SHO image in the original Instagram link.
Unfortunately it happens relatively often that the APOD text don't refers to the original notes of the authors...

APOD Robot wrote: ↑Mon Apr 10, 2023 4:07 am Explanation: ... The featured image ...

Chris Peterson wrote: ↑Mon Apr 10, 2023 1:44 pm I don't know if they're scientifically assigned or not. My objection is that there is no information about this image to be found, so it's essentially useless for anything other than admiring pretty colors. Not an image that should be accepted for APOD, IMO.

AVAO wrote: ↑Mon Apr 10, 2023 8:15 pm The author describes it as a SHO image in the original Instagram link.
Unfortunately it happens relatively often that the APOD text don't refers to the original notes of the authors...

APOD Robot wrote: ↑Mon Apr 10, 2023 4:07 am Explanation: ... The featured image ...

Chris Peterson wrote: ↑Mon Apr 10, 2023 1:44 pm ...Not an image that should be accepted for APOD, IMO.

Ann wrote: ↑Mon Apr 10, 2023 6:22 pm

Chris Peterson wrote: ↑Mon Apr 10, 2023 3:06 pm

Ann wrote: ↑Mon Apr 10, 2023 3:00 pm

Chris, how do you assign scientific colors to a narrowband image?

Ann

The choice of mapping is critical to showing certain features. If that choice is carried out with that intent (as opposed to simple aesthetics) I'd very much call that "scientific". The Hubble palette, for instance, was not created for the purpose of making images "pretty". People who design or choose false color and pseudocolor palettes understand human vision, and why specific assignments make sense for specific information goals.

I get that. The Hubble palette usually shows OIII as blue, Hα as green NII (or SII) as red. The wavelengths of Hα and NII (or SII) are both red and so similar that they would look identical in RGB images, but they do represent very different levels of ionization, and the Hubble palette makes them look very clearly different.

I still don't think that the Hubble palette is "scientific", but I can see that it is practical and useful.

Ann

Chris Peterson wrote: ↑Mon Apr 10, 2023 3:06 pm

Ann wrote: ↑Mon Apr 10, 2023 3:00 pm

Chris Peterson wrote: ↑Mon Apr 10, 2023 1:44 pm

I don't know if they're scientifically assigned or not. My objection is that there is no information about this image to be found, so it's essentially useless for anything other than admiring pretty colors. Not an image that should be accepted for APOD, IMO.

Chris, how do you assign scientific colors to a narrowband image?

Ann

The choice of mapping is critical to showing certain features. If that choice is carried out with that intent (as opposed to simple aesthetics) I'd very much call that "scientific". The Hubble palette, for instance, was not created for the purpose of making images "pretty". People who design or choose false color and pseudocolor palettes understand human vision, and why specific assignments make sense for specific information goals.

Ann wrote: ↑Mon Apr 10, 2023 3:00 pm

Chris Peterson wrote: ↑Mon Apr 10, 2023 1:44 pm

Ann wrote: ↑Mon Apr 10, 2023 5:39 am Of course, I object to the caption's claim that the colors of the APOD have been scientifically assigned. There is nothing scientific about them. They were just chosen to look good, and yes, they do look quite good.

I don't know if they're scientifically assigned or not. My objection is that there is no information about this image to be found, so it's essentially useless for anything other than admiring pretty colors. Not an image that should be accepted for APOD, IMO.

Chris, how do you assign scientific colors to a narrowband image?

Ann

Chris Peterson wrote: ↑Mon Apr 10, 2023 1:44 pm

Ann wrote: ↑Mon Apr 10, 2023 5:39 am Of course, I object to the caption's claim that the colors of the APOD have been scientifically assigned. There is nothing scientific about them. They were just chosen to look good, and yes, they do look quite good.

I don't know if they're scientifically assigned or not. My objection is that there is no information about this image to be found, so it's essentially useless for anything other than admiring pretty colors. Not an image that should be accepted for APOD, IMO.

Ann wrote: ↑Mon Apr 10, 2023 5:39 am Of course, I object to the caption's claim that the colors of the APOD have been scientifically assigned. There is nothing scientific about them. They were just chosen to look good, and yes, they do look quite good.

ESO wrote:
This intriguing new view of a spectacular stellar nursery IC 2944 is being released to celebrate a milestone: 15 years of ESO’s Very Large Telescope. This image also shows a group of thick clouds of dust known as the Thackeray globules silhouetted against the pale pink glowing gas of the nebula. These globules are under fierce bombardment from the ultraviolet radiation from nearby hot young stars. They are both being eroded away and also fragmenting, rather like lumps of butter dropped onto a hot frying pan. It is likely that Thackeray’s globules will be destroyed before they can collapse and form new stars.