Jump to content


Photo

Jupiter 2 and the GRS

  • Please log in to reply
14 replies to this topic

#1 Dennis_S253

Dennis_S253

    Surveyor 1

  • -----
  • Posts: 1729
  • Joined: 22 Nov 2011
  • Loc: West Central Florida

Posted 07 December 2012 - 08:54 AM

Has anyone confirmed the accuracy of the Jupiter 2 program? I've seen some threads that said to change the absolute position of Jupiter to 188. I tried that one night but still didn't see the GRS. I have also read that the GRS is not as red as it was in the 70's. According to Jupiter 2 the GRS should be center at 7:44 EST tonight. Can anyone confirm this? Are there any tricks to viewing the GRS? A filter or something?

#2 Pinbout

Pinbout

    Cosmos

  • *****
  • Posts: 8035
  • Joined: 22 Feb 2010
  • Loc: nj

Posted 07 December 2012 - 09:05 AM

I use sky&telescope's grs thingy

and they have it at 7:37pm

#3 Tony Flanders

Tony Flanders

    Voyager 1

  • *****
  • Posts: 11209
  • Joined: 18 May 2006
  • Loc: Cambridge, MA, USA

Posted 07 December 2012 - 09:09 AM

Has anyone confirmed the accuracy of the Jupiter 2 program? I've seen some threads that said to change the absolute position of Jupiter to 188. I tried that one night but still didn't see the GRS. I have also read that the GRS is not as red as it was in the 70's. According to Jupiter 2 the GRS should be center at 7:44 EST tonight.


That's correct -- give or take 15 minutes. A GRS transit isn't exactly a single, well-defined moment.

Are there any tricks to viewing the GRS? A filter or something?


Yes, non-red filters such as blue definitely make the Great Red Spot appear darker.

However, the first thing to look for isn't the GRS itself but rather the thin spot that it makes in the South Equatorial Belt (SEB). That's very distinctive.

Good optics, good collimation, and good seeing are all very important. Sadly, Jupiter will still be fairly low at 7:44, which is a serious handicap.

#4 REC

REC

    Fly Me to the Moon

  • *****
  • Posts: 5359
  • Joined: 20 Oct 2010
  • Loc: NC

Posted 07 December 2012 - 09:34 AM

Quick question to ask in this thread. What is the minimum power needed to see it clearly on a night of good seeing?

Thanks,

Bob

#5 JasonBurry

JasonBurry

    Ranger 4

  • -----
  • Posts: 377
  • Joined: 27 Apr 2012
  • Loc: Cape Spencer, NB, Canada

Posted 07 December 2012 - 09:39 AM

I can make out the GRS well enough at 100x in my 8" dob, but much prefer to observe it at about 200x.

J

#6 Dennis_S253

Dennis_S253

    Surveyor 1

  • -----
  • Posts: 1729
  • Joined: 22 Nov 2011
  • Loc: West Central Florida

Posted 07 December 2012 - 09:57 AM

Thanks Tony, pointing out the thin spot opened my eyes. I never thought about that. And yes, Jupiter will only be about 30* above the horizon for me at 7:44. A little later this month will be better.
Thanks Bob for bringing that question up also. With my 6", I usually view at 133x and 161x. But I think Tony made another good point also..."Good optics, good collimation, and good seeing are all very important". Thanks for the help...

#7 REC

REC

    Fly Me to the Moon

  • *****
  • Posts: 5359
  • Joined: 20 Oct 2010
  • Loc: NC

Posted 07 December 2012 - 10:28 AM

That what I thought it might be, will try the 120-160x range. I also get a good exit pupil at those powers.
Thanks!

#8 frito

frito

    Apollo

  • -----
  • Posts: 1183
  • Joined: 05 Oct 2012
  • Loc: Fremont, CA

Posted 07 December 2012 - 02:26 PM

I made out the GRS in my XT8 with the 16mm Nagler in last night, thats a mere 75x magnification.

as Tony said look for the dip in the SEB. also look for the 4th belt that you often don't see because its only dark as it trails the GRS and on the other side of the planet its too light to make out in most scopes i think. also it helps to look for the oval dip in the belt the GRS is on, its pretty obvious as well.

#9 Tony Flanders

Tony Flanders

    Voyager 1

  • *****
  • Posts: 11209
  • Joined: 18 May 2006
  • Loc: Cambridge, MA, USA

Posted 07 December 2012 - 02:53 PM

As Tony said look for the dip in the SEB. also look for the 4th belt that you often don't see because its only dark as it trails the GRS and on the other side of the planet its too light to make out in most scopes i think.


See my colleague Sean's jaw-dropping photo of Jupiter at the bottom of This Week's Sky at a Glance.

#10 Regos

Regos

    Sputnik

  • *****
  • Posts: 33
  • Joined: 01 Feb 2012
  • Loc: East Tennessee

Posted 07 December 2012 - 02:57 PM

And yes, Jupiter will only be about 30* above the horizon for me at 7:44. A little later this month will be better.


Also remember that Jupiter's days are ~9 hours and you won't need to wait later in the month for a GRS transit when Jupiter is high. For instance, the GRS transit occurred at 11:46 EST PM last night, when Jupiter was high.

#11 frito

frito

    Apollo

  • -----
  • Posts: 1183
  • Joined: 05 Oct 2012
  • Loc: Fremont, CA

Posted 07 December 2012 - 04:20 PM

As Tony said look for the dip in the SEB. also look for the 4th belt that you often don't see because its only dark as it trails the GRS and on the other side of the planet its too light to make out in most scopes i think.




See my colleague Sean's jaw-dropping photo of Jupiter at the bottom of This Week's Sky at a Glance.


excellent image of Jupiter there.

A few weeks ago i made my first attempt at sketching jupiter here is a link

http://www.cloudynig...5538759/page...

if one is persistent and waits for the right moments you can make a lot of the major features out that are in photos. i was able to see the GRS, the turbulence following it in the SEB and even the festoons coming off the NEB

#12 Seldom

Seldom

    Viking 1

  • -----
  • Posts: 835
  • Joined: 05 Aug 2012
  • Loc: N of Cedar City Light Dome

Posted 07 December 2012 - 05:38 PM

Has anyone confirmed the accuracy of the Jupiter 2 program? I've seen some threads that said to change the absolute position of Jupiter to 188. I tried that one night but still didn't see the GRS. I have also read that the GRS is not as red as it was in the 70's. According to Jupiter 2 the GRS should be center at 7:44 EST tonight. Can anyone confirm this? Are there any tricks to viewing the GRS? A filter or something?

Jupiter 2's been working fine for me. It shows the GRS rising right now. My eye's must not be as sensitive as the video camera in Tony's link, because last night I didn't see as much contrast in the body of the spot. It's more like a pool of creamy coffee with a creamless outline. Glare can also be a problem. Clouds last night made it easier to see as did throwing a towel over the end of my Newt on a couple of earlier occasions.

#13 frito

frito

    Apollo

  • -----
  • Posts: 1183
  • Joined: 05 Oct 2012
  • Loc: Fremont, CA

Posted 07 December 2012 - 05:41 PM

Has anyone confirmed the accuracy of the Jupiter 2 program? I've seen some threads that said to change the absolute position of Jupiter to 188. I tried that one night but still didn't see the GRS. I have also read that the GRS is not as red as it was in the 70's. According to Jupiter 2 the GRS should be center at 7:44 EST tonight. Can anyone confirm this? Are there any tricks to viewing the GRS? A filter or something?

Jupiter 2's been working fine for me. It shows the GRS rising right now. My eye's must not be as sensitive as the video camera in Tony's link, because last night I didn't see as much contrast in the body of the spot. It's more like a pool of creamy coffee with a creamless outline. Glare can also be a problem. Clouds last night made it easier to see as did throwing a towel over the end of my Newt on a couple of earlier occasions.


my visual observations agree with your description of the GRS. it can be quite hard to see the creamy swirls in the center sometimes but it is there.

#14 Ed D

Ed D

    Gemini

  • *****
  • Posts: 3079
  • Joined: 30 Apr 2010
  • Loc: Sunny South Florida

Posted 08 December 2012 - 08:27 AM

"Are there any tricks to viewing the GRS? A filter or something?"

Conditions are everything when observing planets. There are nights the humidity, heat waves, haze, etc., are bad enough that a smaller scope will be preferable to a larger one. Also, use the magnification that gives the sharpest image detail, not necessarily the highest magnification, at the time you are observing. This not only varies from night to night, but can vary as the night wears on.

Broadband filters, aka Light Pollution or Moon and Skyglow filters, are commonly used for observing Jupiter. They tend to increase contrast between the light and dark areas making the features stand out a little better without any overpowering color. Another one I sometimes use is my yellow planetary filter on nights that the contrast is pretty low. The effect is similar to using yellow tinted glasses on a heavily overcast day.

Nights of pristine conditions and planets perfectly poised are far and few. But, those rare times when all comes together... :jump:

Ed D

#15 Seldom

Seldom

    Viking 1

  • -----
  • Posts: 835
  • Joined: 05 Aug 2012
  • Loc: N of Cedar City Light Dome

Posted 08 December 2012 - 11:14 AM

Jupiter 2's prediction of the Io transit time last night was right on (10:15 MST).






Cloudy Nights LLC
Cloudy Nights Sponsor: Astronomics