Uranus in Near-infrared
Update 2017 Nov 21: There is a web page for the OPAL project here that I was unaware of when I posted this: archive.stsci.edu/prepds/opal/
Uranus imaged by Hubble on 2017-10-27 at 01:15 UCT (that's 9 days ago from the time of this posting). I believe the moon to the right is Miranda. A few smaller moons are also visible in the image, and several more still are detected in the raw data, but are too dim to see with this processing. The brightening in the longer wavelengths at the limb of the planet is real, though I do not understand exactly why it happens.
This proposal is on the Director's Discretionary budget, so there's no proprietary period. Also available are recent images of Neptune! If you enjoy planetary processing, now is a good chance to get your hands on some fresh, public data. You can head over to the MAST portal to find it. Use an advanced search to filter it down to only images of moving targets taken in the last couple of months, and then sort the list by start time. Alternatively, you can also filter it by Proposal ID to 15262 and look at all the data currently available from that proposal. Sometimes there are gems from other proposals, though.
The moons and a small bright spot appear multi-colored because they moved in the moments between each exposure. The blue channel is not infrared, but rather a narrowband filter typically used to capture Hα and [N II] emission. It seems to work ok here as a kind of shorter wavelength red filter, with the other two channels containing more red and near-infrared. I found the combination gave it a pleasing amount of color separation without going into ultra vivid, technicolor land as so many infrared images do.
A great thing about these wavelengths is that the rings and cloud bands are clearly visible at the same time with the right tweaks to the value curves. Most images of Uranus have had separate processing for the rings and the planet because the rings are so very dim. I gave them both the same processing instead of separating them.
Here, you can also see the "X" shaped light pattern emanating from the planet, which is just like a diffraction spike we see on bright stars. This pattern, and the faint, fuzzy, glowing halo are effects produced as light interacts with the telescope—not something that is actually there around the planet.
The image is scaled up 200% from its original form. The latest version of Photoshop introduced a new resampling algorithm which they have called "Preserve Details 2.0" which maintains some of the sharper edges better than previous methods.
Data from the following proposal were used to create this image:
Hubble 2020: Outer Planet Atmospheres Legacy (OPAL) Program
Red: WFC3/UVIS F845M
Green: WFC3/UVIS F763M
Blue: WFC3/UVIS F657N
North is up.
Uranus in Near-infrared
Update 2017 Nov 21: There is a web page for the OPAL project here that I was unaware of when I posted this: archive.stsci.edu/prepds/opal/
Uranus imaged by Hubble on 2017-10-27 at 01:15 UCT (that's 9 days ago from the time of this posting). I believe the moon to the right is Miranda. A few smaller moons are also visible in the image, and several more still are detected in the raw data, but are too dim to see with this processing. The brightening in the longer wavelengths at the limb of the planet is real, though I do not understand exactly why it happens.
This proposal is on the Director's Discretionary budget, so there's no proprietary period. Also available are recent images of Neptune! If you enjoy planetary processing, now is a good chance to get your hands on some fresh, public data. You can head over to the MAST portal to find it. Use an advanced search to filter it down to only images of moving targets taken in the last couple of months, and then sort the list by start time. Alternatively, you can also filter it by Proposal ID to 15262 and look at all the data currently available from that proposal. Sometimes there are gems from other proposals, though.
The moons and a small bright spot appear multi-colored because they moved in the moments between each exposure. The blue channel is not infrared, but rather a narrowband filter typically used to capture Hα and [N II] emission. It seems to work ok here as a kind of shorter wavelength red filter, with the other two channels containing more red and near-infrared. I found the combination gave it a pleasing amount of color separation without going into ultra vivid, technicolor land as so many infrared images do.
A great thing about these wavelengths is that the rings and cloud bands are clearly visible at the same time with the right tweaks to the value curves. Most images of Uranus have had separate processing for the rings and the planet because the rings are so very dim. I gave them both the same processing instead of separating them.
Here, you can also see the "X" shaped light pattern emanating from the planet, which is just like a diffraction spike we see on bright stars. This pattern, and the faint, fuzzy, glowing halo are effects produced as light interacts with the telescope—not something that is actually there around the planet.
The image is scaled up 200% from its original form. The latest version of Photoshop introduced a new resampling algorithm which they have called "Preserve Details 2.0" which maintains some of the sharper edges better than previous methods.
Data from the following proposal were used to create this image:
Hubble 2020: Outer Planet Atmospheres Legacy (OPAL) Program
Red: WFC3/UVIS F845M
Green: WFC3/UVIS F763M
Blue: WFC3/UVIS F657N
North is up.