|
A brown dwarf with an ultra-bright aurora discovered
|
|
| FaceDeer | Date: Wednesday, 29.07.2015, 23:05 | Message # 1 |
|
Space Pilot
Group: Users
Canada
Messages: 117
Status: Offline
| Here's a neat thing I just read about; the brown dwarf LSR J1835+3259 has an ultra-bright aurora around a million times brighter than Earth's. They're not sure why yet because the brown dwarf doesn't have a companion star that would normally be the source of energetic particles that cause aurorae, but one of the speculated causes is an Earth-sized planet orbiting the brown dwarf interacting with its magnetic field in a similar manner to how Io does with Jupiter.
So, a couple of neat phenomena are described in this article that could suggest some things to add to Space Engine.
- Brown dwarfs can have aurorae
- Big gas giants can have insanely powerful magnetic fields that in turn can lead to insanely spectacular aurorae
- Planets and moons like Io can fill a magnetic field with charged particles suitable for creating aurorae. I suspect that currently planets are given aurorae based on random chance, but someday it'll probably make sense to consider the planet's environment when determining whether they get them.
- Aurora colour depends on the composition of the atmosphere. Kind of a separate issue, but I was reminded of it because it was mentioned in here. Space Engine doesn't currently give a real composition to atmospheres but maybe someday.
Anyway. Would add some variety to brown dwarfs if some of them had spectacular displays like this.
Edited by FaceDeer - Wednesday, 29.07.2015, 23:05 |
| |
| |
| FastFourierTransform | Date: Thursday, 30.07.2015, 08:44 | Message # 2 |
 Pioneer
Group: Local Moderators
Spain
Messages: 542
Status: Offline
| Quote FaceDeer (  ) Big gas giants can have insanely powerful magnetic fields that in turn can lead to insanely spectacular aurorae
I find this quite spectacular as not to be in SE. We held a similar discussion here: http://en.spaceengine.org/forum/8-2316-1 There are some ideas if you are interested.
|
| |
| |
| n0b0dy | Date: Thursday, 30.07.2015, 11:30 | Message # 3 |
 Explorer
Group: Users
Pirate
Messages: 297
Status: Offline
| I was about to post about this but I was ninja'd 
|
| |
| |
| FaceDeer | Date: Thursday, 30.07.2015, 21:57 | Message # 4 |
|
Space Pilot
Group: Users
Canada
Messages: 117
Status: Offline
| Quote FastFourierTransform ( )
That would be quite pretty, indeed. Do you know of any papers that have been published regarding the possibility of visible light emissions from radiation belts like this? I was tempted to mention something about how Io spews out interesting streams of charged particles and how that might be visible under some extreme circumstances in this post, but I didn't want to stray too far into speculation since Space Engine tries to be realism-focused.
Other spectacular-looking aurora-related phenomena that might be worth putting into Space Engine someday are:
Aurorae on planets with multi-polar magnetic fields (for example, Mars has only small localized magnetic fields "frozen" from back in the day when it had a global field, and it's thought that when Earth is undergoing a magnetic field reversal its magnetic field breaks up into a chaotic patchwork for a while too). This would only require modification of the existing aurora shader to allow for more complex shapes than the existing squiggly circles.
Phosphorescence in surface minerals on airless worlds that are subject to high radiation environments. I once saw some artwork depicting a surface view on a pulsar planet and the terrain was glowing in patches and streaks from the intense radiation bombardment, I imagine it'd be really beautiful to see those glows shifting and flickering like an aurora does.
Didn't have any articles at my fingertips for those, though.
Edited by FaceDeer - Thursday, 30.07.2015, 22:01 |
| |
| |
| FastFourierTransform | Date: Sunday, 02.08.2015, 19:23 | Message # 5 |
|
Pioneer
Group: Local Moderators
Spain
Messages: 542
Status: Offline
| Quote FaceDeer ( ) Do you know of any papers that have been published regarding the possibility of visible light emissions from radiation belts like this?
I didn't find any documentation about this, it was just a wild speculation. The Universe is inmense, maybe things like this appear in some places if it is possible for some concrete circumstances. I think visible plasma emissions from exoplanets is not something well studied maybe because of the lack of scientific interest on something that specific by now. But maybe someone could make the calculations and see if this is reasonably rigorous. Maybe a plasma trapped in the radiation belts can't be visible because it would never get so dense (maybe there could be an accumulation mechanism) or so hot as to glow in the visible range, or maybe yes, I don't know.
Exotic worlds have to be taken into account but always with realism as you said (the greatness of Space Engine is the reliability of those depictions).
Quote FaceDeer ( ) I was tempted to mention something about how Io spews out interesting streams of charged particles and how that might be visible under some extreme circumstances in this post
Maybe we should discuss this in the other thread. But I agree completely that this is a fascimating issue. In fact there is a real visible glow on Io created by those extreme currents. This image was taken in the visible range by the cameras of the Galileo spacecraft on May 31, 1998, from the night side of Io:
The glow comes from charged particles in the radiation belt of Jupiter smashing the surface and atmosphere of this body. The green glow corresponds to sodium, red from oxigen and the blue glow comes from the interaction with volcanic gases.
If Jupiter had a gaseous belt in the same region wouldn't it glow like Io? or it's unstable? By now we can only assure that Io lights up because of this phenomena. It would be an awesome feature for Space Engine.
Either way, Io and other moons have a great electric influence on Jupiter aurora's because of electric discharges. The discharge spots are even visible in the polar regions opf the planet:
Quote FaceDeer ( ) Aurorae on planets with multi-polar magnetic fields
Wow, I don't want to be a pain in the neck but I asked for exactly that on this thread: http://en.spaceengine.org/forum/21-11-48054-16-1420670037
Martian auroras are visible in the UV frequencies because of the atmospheric composition of the planet but indeed I found very important to add those strange auroral structures on Space Engine to show multipolar magnetic fields on alien planets. Maybe an extremely magnetized mountain could have its own auroral structure in the skies.
Quote FaceDeer ( ) Phosphorescence in surface minerals on airless worlds that are subject to high radiation environments.
Wow, we trully are soulmates or something because I have been calculating the last week the posibility of finding such worlds. I will post the details in a new thread one day soon. Mineral phosphorescence could be quite noticiable with some specific parameters (for example in the surface of bodies located quite far away from Blue Giants and Wolf Rayet stars). Soon I will post, soon... 
Edited by FastFourierTransform - Sunday, 02.08.2015, 19:59 |
| |
| |
| Alienart | Date: Sunday, 08.11.2015, 18:08 | Message # 6 |
 Space Tourist
Group: Users
United States
Messages: 38
Status: Offline
| I didn't want to start a new thread about this and this thread seems pretty close to a similar question I have:
Auroras aside, would brown dwarfs emit any kind of visible at all due to their internal heat, as in the way a coal glows red under its ash?
I need to know because I am working on a space art painting -- yes, with actual paint instead of digital. None of the astronomers at the university where I work have been able or willing to respond to this question.
I know that brown dwarfs are often depicted as bright red, but I'm thinking it would look cool if they have Jupiter-like clouds dimly lit from within with a ruddy glow showing through the spaces between the clouds or storm systems.
Does anyone know? Are they strictly infrared or could we see them with our own eyes if we were in the vicinity?
|
| |
| |
| FaceDeer | Date: Sunday, 08.11.2015, 20:48 | Message # 7 |
|
Space Pilot
Group: Users
Canada
Messages: 117
Status: Offline
| Brown dwarfs do indeed glow naked-eye visible orange or red from their internal heat. Some of them, anyway. Brown dwarfs come in a wide range of temperatures and the coolest ones are just a few hundred degrees, cold enough that they're probably dark to the human eye. And the hottest brown dwarfs are actually about as hot as a red dwarf, so they'd look a lot like a "real" star at that end.
I think what you're looking for is the middle range, where the brown dwarf is hot enough to be glowing but cool enough that it can have high-altitude clouds of solid or liquid particles. here's an artist's conception of a T-class brown dwarf that falls in that range, along with some discussion of the sorts of clouds and "weather" that might be found on such stars.
|
| |
| |
| Alienart | Date: Monday, 09.11.2015, 00:25 | Message # 8 |
|
Space Tourist
Group: Users
United States
Messages: 38
Status: Offline
| ^Excellent! Thanks so much, Astronaut! It's amazing what simple facts slip by us just because they may seem too obvious to mention, so I've been looking a very long time for this information.
As icing on the cake I'm going to give my brown dwarf some kind of accretion disk or maybe a ring system, also lit from within.
|
| |
| |
| FaceDeer | Date: Friday, 11.12.2015, 06:56 | Message # 9 |
|
Space Pilot
Group: Users
Canada
Messages: 117
Status: Offline
| And brown dwarf aurorae appear to be in for the next verison. Yay!
|
| |
| |
ENG
New site
Canada 
Spain 
Pirate 
United States