Opposition of Jupiter

Very nice capture with all the moons close in the framing . Those SN-6" scopes are very nice scopes . I have a Bushnell SN-6" stored away . They are really nice scopes for viewing !

Celestron wrote in post #17930088
Very nice capture with all the moons close in the framing . Those SN-6" scopes are very nice scopes . I have a Bushnell SN-6" stored away . They are really nice scopes for viewing !

Thanks! Yeah, I've got 7mm and 26mm eyepieces for viewing. A couple years ago I watched a moon disappear behind Jupiter while another reappeared on the other side of it. When I lived in a high-rise apartment I would watch the moon set across the sound and watch craters disappear behind a tree and reappear on the otherside, literally watching the rotation the of Earth. It's been a good scope to me, even with the limited use I am able to get due to living in cities.

I think now that the weather is getting nice I'm going to start paying attention to the ISS and see when it will be in my viewing window and see if I can image that through the telescope. I remember a few years back you got a nice image of it through your scope. I, unfortunately, have a very tiny window into the Cosmos. About a 2 hour viewing window towards the south-southwest due to all the trees around us. Which is why I had to wait until 2:30-4:30am to image the opposition of Jupiter. Ideally, I would have done it when Jupiter was transiting around midnight, to have less atmospheric interference, but you work with what you've got and do your best to make a quality image.

So, just for fun, some facts about the objects in this image. I posted this elsewhere, so I figured I'd share with y'all as well.

Galileo discovered these moons in 1610 and made the first direct observation of celestial bodies orbiting another celestial body, hard evidence against a geocentric model of the universe. Io is the innermost of the Galilean moons, and also the most geologically active world in the solar system due to tidal forces heating the moon powering over 400 active volcanoes. Europa's surface is covered by water ice with a worldwide liquid ocean beneath, making it a strong candidate for extraterrestrial life. Ganymede is the largest moon in solar system, even larger than Mercury, and is the only moon known to have a magnetosphere due to convection is a liquid iron core just like Earth. Callisto may be the best place for a future human base for human exploration of the outer solar system; it is the most heavily cratered moon and may also contain a liquid ocean beneath its surface. All 4 of these of moons are larger than any of the dwarf planets, including Pluto.

That's a beautiful image.

Incidentally, you can watch transits of the Galilean moon's and their shadows quite frequently. Io, for example, orbits Jupiter roughly every 42.5 hours.

There's a cool story about how an odd behavior observed in the orbit of Io led to the realization that "light" actually has a speed (it was believed to be instant.)

In those days, astronomers timed the orbit of Io down to the second and then made tables predicting the times when Io would disappear behind Jupiter and then later re-emerge on the other side. These tables predicted Io's occultations out to a few years.

But something went wrong when they made observations using the tables... Io started to lag behind the table's predicted times. Eventually Io was quite a few minutes late. Something was slowing down the orbit of Io... but what? And then more bizarrely... Io started speeding up again. It started to arrive earlier and earlier until it not only made up for all lost time but now started to get occulted earlier than the tables predicted.

Nobody could figure out what was causing a moon to slow down and speed up.

But a Dutch astronomer named Ollie Rømer noticed a coincidence... whenever Io was "late" the Earth was also much farther away from Jupiter. Whenever Io was "early" Earth was much closer to Jupiter.

Rømer suggested that Io wasn't changing speeds at all... but that light must have a "speed" and it's simply taking longer for the light to reach our planet when we're on the far side of the solar system from Jupiter.

He was, of course, ridiculed for such an idea. In those days it was simply accepted that light was instant. Eventually Rømer's ideas about the speed of light were accepted. This predated any accurate measurements of distances between planetary bodies in the solar system so the estimated speeds of light were wildly wrong... but it was at least progress that science accepted that light must actually have a speed.

I still look up the transit times for the Galilean moon's to see if there will be any transits visible on the nights when I'm able to observe.

TCampbell wrote in post #17931055
That's a beautiful image.

Incidentally, you can watch transits of the Galilean moon's and their shadows quite frequently. Io, for example, orbits Jupiter roughly every 42.5 hours.

There's a cool story about how an odd behavior observed in the orbit of Io led to the realization that "light" actually has a speed (it was believed to be instant.)

Thank you! And yeah, that's a great story about Rømer and the speed of light. One I am familiar with, but I have a degree in physics (and took some astronomy in college too). It's my fascination with light that led me into photography. I used to teach "Light & Lasers" to non-science majors. My students stopped going to classes and attended my TA sessions only as I taught the material better than the prof. While flattered, I discouraged that behavior... but all my students passed. Astronomy (along with physics) is the oldest science and they are deeply tied to the roots of the Scientific Revolution. I love the sense of of history and that connection to the past you feel when setting up the telescope and watching ancient light that has been traveling across the universe since before Galileo set up his telescope.

Edit: Do you have links to transit times for the moons? I want to set up my telescope some time and watch these transits myself. Thanks for the tip!

I use the events in Starry Night Pro Plus. But there are some online websites that will give you transit times as well.

Here's one: http://www.shallowsky.​com/jupiter/

On Monday evening at around 9pm EDT there will be a double transit of both Io and Europa.

Thanks again. Unfortunately I'll be traveling on Monday so I'll miss this pass, but I'm going to check out Starry Night Pro Plus. That sounds like it is something right up my alley.

This is how to show Jupiter.

Hopefully the folks who have commented are still reading this thread. If not, I may need to start another in the Astro Talk forum.

How do I add this photo to my gallery? What do y'all do when you have not used a standard lens and shot with prime focus? In order to add an image to my gallery, I need to select a lens from the dropdown, but no telescopes are in the equipment database. So in order to add this to my gallery I would need to pick some lens I have and mark this image incorrectly as shot with that lens. I don't want to do that. Not only would this image be mislabeled, but then it would show up in the gallery for that lens as well, where it doesn't belong. So is there some sort of workaround to this? Or is it possible to add telescopes to the database? Thanks.

samsen wrote in post #17931246
This is how to show Jupiter.

Thank you. I am very pleased with the results in this image.

heldGaze wrote in post #17930065

Did anyone else get out the telescope for the opposition?

Looks great.
I'm interested in this 2x Barlow with T-mount that you speak of. Could I use it with my small 80mm ED refractor?

Levina de Ruijter wrote in post #17931440
Looks great.
I'm interested in this 2x Barlow with T-mount that you speak of. Could I use it with my small 80mm ED refractor?

Thank you.

I don't know much about your specific telescope, but probably. It is basically an "eyepiece" that instead of a having a cup for your eye, it has screw threads onto which you can screw a T-ring that is specific to your camera. The T-ring is basically like a camera lens mount. It connects to your camera but instead of having a lens it has screw threads which attach to this. Once you connect everything, you just put this into your telescope where the eyepiece goes, lock it in tight, and use live view on you camera to focus and frame the shot. Use focus magnification if you camera has that feature of course.

Here is a link to what I have, in addition to this item, you would also need to buy that T-ring specific to you camera. I actually have a T-ring for Canon cameras, and previously would use it with my Canon 40D, but I have an adapter for the Sony α7R II which makes Canon lenses attach to the Sony body.

http://www.telescopes.​com …lens-universal-1-1-4-inch

heldGaze wrote in post #17931450
Thank you.

I don't know much about your specific telescope, but probably. It is basically an "eyepiece" that instead of a having a cup for your eye, it has screw threads onto which you can screw a T-ring that is specific to your camera. The T-ring is basically like a camera lens mount. It connects to your camera but instead of having a lens it has screw threads which attach to this. Once you connect everything, you just put this into your telescope where the eyepiece goes, lock it in tight, and use live view on you camera to focus and frame the shot. Use focus magnification if you camera has that feature of course.

Here is a link to what I have, in addition to this item, you would also need to buy that T-ring specific to you camera. I actually have a T-ring for Canon cameras, and previously would use it with my Canon 40D, but I have an adapter for the Sony α7R II which makes Canon lenses attach to the Sony body.

http://www.telescopes.​com …lens-universal-1-1-4-inch

Thank you for the reply and the link.
I have done a bit of Deep Sky photography a few years ago so I have all the adapters, mounts, extending tubes etc. My refractor is excellent but 80mm is not really suited for the planets and my results are nothing even close to yours. I didn't know there existed Barlows with a t-mount, so I'd be interested in trying that. It's like a combination of prime focus and afocal. I'm excited to try it out. Thank you again.

Levina de Ruijter wrote in post #17931481
Thank you for the reply and the link.
I have done a bit of Deep Sky photography a few years ago so I have all the adapters, mounts, extending tubes etc. My refractor is excellent but 80mm is not really suited for the planets and my results are nothing even close to yours. I didn't know there existed Barlows with a t-mount, so I'd be interested in trying that. It's like a combination of prime focus and afocal. I'm excited to try it out. Thank you again.

Of course, glad I could help. Best of luck in your future attempts at imaging the planets. If you're not familiar with it already, you may want to read up on Dawes Limit. Even in the best of conditions, our telescopes have limited resolving power, as described by this limit. It's my understanding that viewing conditions often reduce this figure by about half.

https://en.wikipedia.o​rg/wiki/Dawes%27_limit

With a refractor there is an adapter to attach to your camera with T-Ring and this setup is put in place of the diagonal . This way you can use your 80mm scope as a large lens but you are correct that it's not planet friendly. Usually it is much easier to image planets with a larger scope and proper adapters . I have basically retired from astroimaging , I have a Celestron 8" SCT stored away and going to sell eventually with all the attachments needed for a canon SLR . It's not on a GoTo mount, it has tracking motors and has to be manually polar aligned. With new technology in scopes today you just set one up and push a button and your done. So much is missing from learning these days for new amateur astronomers.

Basically tho if you have a big pocket book anything is possible to do to capture that image you want.