Stellarium GRS position on Jupiter

[bus_ter]

It's been a while (years) since I've used Stellarium to predict the GRS position. Does it now work correctly? or do you still have to find a setting online and apply it to the Stellarium config file? If so does anyone have the current figure?

[beamish]

for accurate GRS d/load WinJupos 10

[Tinker1947]

Get Jupiter up on the Stellarium screen, zoom in, then advance the time, looking at it today it goes off the right side around midnight and comes back around 06:00.....

[bus_ter]

for accurate GRS d/load WinJupos 10

I downloaded this and had a play. Afraid it's a bit too complicated for me and I couldn't work out how to show the GRS timings

Get Jupiter up on the Stellarium screen, zoom in, then advance the time, looking at it today it goes off the right side around midnight and comes back around 06:00.....

I'm quite aware how to see the GRS on stellarium. My questions is, have they fixed the accuracy of this in the last year or so? It used to be way off and you had to put in a correction factor into the stellarium config file.

[Tinker1947]

I downloaded this and had a play. Afraid it's a bit too complicated for me and I couldn't work out how to show the GRS timings

I'm quite aware how to see the GRS on stellarium. My questions is, have they fixed the accuracy of this in the last year or so? It used to be way off and you had to put in a correction factor into the stellarium config file.

Sorry its to cloudy to check....

[bus_ter]

Well I've answered my own question. I just took a quick and nasty photo of Jupiter.. Stellarium shows the GRS showing.. my picture says ..NO!

Anyone know the current correction factor for Stellarium?? Someone must know what I'm talking about?

[ArmyAirForce]

I just enter the date halfway down this page, and it gives you the transit times.

http://www.skyandtelescope.com/observing/objects/planets/3304091.html?page=1&c=y

[bus_ter]

OK after a lot of trial and error I have calculated what I was trying to find.

To fix the GRS prediction in Stellarium you need to edit this file:

C:\Users\USERNAME\AppData\Roaming\Stellarium\data\ssystem.ini (This is the location for Windows 7/8 - you may need to enable viewing hidden folders)

Change line 161 to read this:

rot_rotation_offset = 95 #just some value good for GRS #old:151

So the current value for November 2012 is '95'.

The GRS is essentially a chaotic weather pattern, and thus can not be forecasted long term. This figure should stay accurate for several months.

If you find this thread sometime in the future, feel free to update this figure to a current value for others to use.

[ArmyAirForce]

Just tried this but it won't let me edit the file, and I've tried a number of different ways. It's not marked as read only.

[bus_ter]

Worked ok for me. I'm logged in with Admin rights and I had Stellarium closed when editing the file. I had to enable 'show hidden items' to see the 'AppData' folder. I used (http://notepad-plus-plus.org/) to edit the file, but that shouldn't have made any difference? Try SAFE mode?

[ArmyAirForce]

Thanks to that link, I've edited the file, but the spot isn't showing in the correct place according to this transit website - http://www.skyandtelescope.com/observing/objects/planets/3304091.html?page=1&c=y

Stellarium now says the closest transit to now is around 19:00 tonight, but the transit website says 13:20 or 23:15 tonight. Something is wrong somewhere!

I'm using Windows 7 and Stellarium 0.11.4

[bus_ter]

I've just tested this. I started Stellarium, forward the time to 23:15 (tonight) and zoomed in on the Spot. It's in the centre of the planet as expected. I tried 1900, and it's not showing.

Have you saved the file and then restarted Stellarium? (sorry if that's obvious).

Can anyone else verify if '95' correctly places the GRS according to forecast?

[ArmyAirForce]

Stellarium was closed when the adjustments were made. I've checked the file, and the new '95' figure is saved in the file. When Stell was opened, and time fast forwarded, the spot isn't where it should be!!

[bus_ter]

OK need a third person to test this ....

[Stu]

Not sure if it uses the same system, but GRS is currently around 185 degrees from the meridian. You could try this figure?

Cheers

Stu

[ArmyAirForce]

Confused! I've tried saving a number of different values this morning, yet every time I start Stellarium, the cloud patterns on Jupiter are in the same position when I zoom in. As I fast forwards time, Jupiter rotates as it should, but as of 9:00am this morning, always starts with the red spot on the far side of the planet.

[bus_ter]

I've tried it on my laptop with a completely different install of Stellarium and it works okay. I have an idea.. could you be changing the config file for a different user than you are logged in as?

[ArmyAirForce]

I'm the only user/admin on my laptop.

[bus_ter]

I'm quite confident after checking on a second computer that it all works fine. For some reason your Stellarium is not reading the system.ini file. Perhaps try reinstalling Stellarium? Try a different pc if you have one?

[Rossco72]

My ssytem file isn't in nice lines. It's one mass of text.

There are a few mentions of rotation offset. How do I know which one to change?

Cheers

Stuart

[bus_ter]

Do 'Find' (ctrl-F) for "#just some value good for GRS" and it should put you to the right line. In front of this is the old value I think it's 251? Anyway change it to 95, save and restart Stellarium.

[StuW]

If you use wordpad to open the file it should parse the linefeeds correctly and be easier to read

Sent from my HTC One X using Tapatalk 2

[bus_ter]

I've also found how to correctly update the position of the GRS in Starry Night.

GOTO --> C:\Program Files (x86)\Starry Night Pro Plus 6\Sky Data\JupiterGRS.txt

Edit the value in the file to read 184.

This figure is actually the current Longitude of the GRS and can be found online (such as the GRS transits site above)

The stellarium figure AFAIK doesn't correspond to anything and is just a correction factor.

[Daggerstab]

The stellarium figure AFAIK doesn't correspond to anything and is just a correction factor.

AFAIK, It's the rotation angle of Jupiter's texture, relative to whatever the rendering engine considers to be the prime meridian.

[deepskeye]

Just updated stellarium.  85 gets the grs very close to the prediction at calsky.com.  I went to Stellarium, data, ssystem.  I opened it in wordpad and did a search for name=jupiter.  The next instance of rot_rotation_offset = is the one I changed.  I had trouble saving my changes until I right clicked on ssystems, clicked on securiy in the properites tab, selected user, and added modify to the permisions.