IPB

Welcome Guest ( Log In | Register )

HST images of Uranus and Neptune
titanicrivers
post Feb 14 2019, 09:16 PM
Post #1


Member
***

Group: Members
Posts: 624
Joined: 1-April 08
From: Minnesota !
Member No.: 4081



Amazing new images from Hubble Space Telescope (HST) of Uranus and Neptune! https://earthsky.org/space/hubble-space-tel...-uranus-neptune
Here are the Hubble site images: http://hubblesite.org/images/news/release/2019-06
Go to the top of the page
 
+Quote Post
 
Start new topic
Replies
antipode
post Feb 15 2019, 06:56 AM
Post #2


Member
***

Group: Members
Posts: 261
Joined: 1-October 06
Member No.: 1206



Uranus especially continues to surprise - Voyager IIs flyby timing and its camera's filterset certainly misled people about how dynamic its atmosphere can be.
In the continuing absence of the followup probes the two ice giants so badly deserve, I look forward to what the ELTs and next gen adaptive optics will achieve.
GMT arrival = 6 years with any luck.

P

Actually, considering the large portion of the visible globe of Uranus covered by that seemingly bright cloud (I presume this is a near IR image), has it had any
effect on the planet's magnitude in the visible?
Go to the top of the page
 
+Quote Post
dolphin
post Feb 17 2019, 06:30 AM
Post #3


Junior Member
**

Group: Members
Posts: 22
Joined: 24-August 07
Member No.: 3405



QUOTE (antipode @ Feb 15 2019, 07:56 AM) *
Uranus especially continues to surprise - Voyager IIs flyby timing and its camera's filterset certainly misled people about how dynamic its atmosphere can be.
In the continuing absence of the followup probes the two ice giants so badly deserve, I look forward to what the ELTs and next gen adaptive optics will achieve.
GMT arrival = 6 years with any luck.

P

Actually, considering the large portion of the visible globe of Uranus covered by that seemingly bright cloud (I presume this is a near IR image), has it had any
effect on the planet's magnitude in the visible?



That was my question. Does Uranus have such complexity in the visible range? If so, that would be markedly different from the uniformity we saw during the Voyager flyby.
Go to the top of the page
 
+Quote Post
JRehling
post Feb 18 2019, 06:26 PM
Post #4


Senior Member
****

Group: Members
Posts: 2246
Joined: 20-April 05
Member No.: 321



QUOTE (dolphin @ Feb 16 2019, 11:30 PM) *
That was my question. Does Uranus have such complexity in the visible range? If so, that would be markedly different from the uniformity we saw during the Voyager flyby.


I think Uranus may have been cheated a bit by the design decisions of Voyager.

The color filters on the Voyager cameras are described in wonderful detail here:
http://www.planetary.org/multimedia/space-...r_response.html

There was no red. The orange filter zeroed out at 650 nm, with a peak around 580nm.

I've taken many multispectral photos of Uranus including B, G, R, and near IR. I can expect easily to resolve the polar hood if nothing else. It is blank as can be in B and G, but the polar hood is easily visible in IR (>685 nm) and dimly in R (595 – 680 nm).

It's a near certitude that an orange filter missed out on a lot of the needed sensitivity for seeing this feature, if it were the same in 1986 as it has been 2016-2018.
Go to the top of the page
 
+Quote Post
JRehling
post Feb 18 2019, 07:38 PM
Post #5


Senior Member
****

Group: Members
Posts: 2246
Joined: 20-April 05
Member No.: 321



Here are pictures I personally took with a 235mm Schmidt–Cassegrain and the aforementioned filters on October 18, 2018. The contrast is evident in the IR image, discernible but subtle in R, and completely absent in the G+B (it is absent in both of those, of course, for it to be absent in the sum of them).

At right is a composite where I used the luminance of the IR image, then colored it with the RGB image but with the red plane doubled. It's a nice appearance, but a bit past the bounds of "true color." The fact that both the hue and the brightness of the cap are different from the rest of the planet speaks to the fact that both IR and R show the hood.

There is also a thin equatorial belt that other observers captured but I did not.

But green does not. So we should expect the Voyager camera, were it taking an image of Uranus today, to turn up something blank because of the lack of a proper red filter.
Attached image(s)
Attached Image
 
Go to the top of the page
 
+Quote Post

Posts in this topic
- titanicrivers   HST images of Uranus and Neptune   Feb 14 2019, 09:16 PM
- - antipode   Uranus especially continues to surprise - Voyager ...   Feb 15 2019, 06:56 AM
|- - dolphin   QUOTE (antipode @ Feb 15 2019, 07:56 AM) ...   Feb 17 2019, 06:30 AM
|- - JRehling   QUOTE (dolphin @ Feb 16 2019, 11:30 PM) T...   Feb 18 2019, 06:26 PM
|- - JRehling   Here are pictures I personally took with a 235mm S...   Feb 18 2019, 07:38 PM
- - titanicrivers   Excellent questions Antipode and Dolphin and furth...   Feb 17 2019, 06:28 PM
- - titanicrivers   From the OPAL site the images of Uranus are taken ...   Feb 18 2019, 08:45 PM
|- - JRehling   The F845 filter is certainly what I'd call inf...   Feb 18 2019, 09:41 PM
|- - titanicrivers   QUOTE (JRehling @ Feb 18 2019, 03:41 PM) ...   Feb 18 2019, 10:41 PM
|- - JRehling   No, I see absolutely no features in Uranus with th...   Feb 18 2019, 11:40 PM
- - titanicrivers   Appreciate your expert commentary JRehling! W...   Feb 20 2019, 09:01 PM
- - titanicrivers   A new publication in Geophysical Research Letters ...   Mar 26 2019, 04:47 PM
- - titanicrivers   The December 2019 issue of Sky and Telescope has a...   Oct 24 2019, 07:42 PM
- - Ian R   Funnily enough, I remember an article of his in an...   Dec 21 2019, 02:37 PM
- - Decepticon   ^^ Did this article have a Concept mission for Ura...   Dec 21 2019, 11:51 PM
|- - titanicrivers   QUOTE (Decepticon @ Dec 21 2019, 05:51 PM...   Jan 9 2020, 08:44 PM
- - titanicrivers   An article speculating on the JWST observations co...   Feb 28 2020, 06:54 PM


Reply to this topicStart new topic

 



RSS Lo-Fi Version Time is now: 8th July 2020 - 11:58 AM
RULES AND GUIDELINES
Please read the Forum Rules and Guidelines before posting.

IMAGE COPYRIGHT
Images posted on UnmannedSpaceflight.com may be copyrighted. Do not reproduce without permission. Read here for further information on space images and copyright.

OPINIONS AND MODERATION
Opinions expressed on UnmannedSpaceflight.com are those of the individual posters and do not necessarily reflect the opinions of UnmannedSpaceflight.com or The Planetary Society. The all-volunteer UnmannedSpaceflight.com moderation team is wholly independent of The Planetary Society. The Planetary Society has no influence over decisions made by the UnmannedSpaceflight.com moderators.
SUPPORT THE FORUM
Unmannedspaceflight.com is a project of the Planetary Society and is funded by donations from visitors and members. Help keep this forum up and running by contributing here.