Is this Uranus ?

[peterbolson]

I was looking through some not very successful photos I took of Jupiter on Nov 11th and found this. From the colour I wondered if it was Uranus, and what is the moon above it ?

Thanks

Peter

[Psychobilly]

Checking in stellarium they were seperated by approximately 41 degree in Azm on the 11-11-11

[peterbolson]

I don't know how apart they were. It was taken with a 50mm lens on my D80

[carldr]

Hi Peter,

It wouldn't be Uranus - It's a good distance away from Jupiter at the moment (about 40 degrees, at a guess.)

I used Stellarium to go back to that evening, and what is odd is that I can't figure out it what you've got there.

I've attached a screenshot of what Jupiter would have looked like at about 10pm on 11/11/2011, trying to match the scale in your image. As you can see, the moon you can see is likely to be Callisto, but I don't know why you haven't also captured Europa and (possibly) Ganymede.

Could the green disc be an internal reflection of either the telescope or the camera?

Could you confirm the time, and perhaps post a couple of other images you took that night?

Regards,

Carl.

[carldr]

Hmm. From what you've said about the lens you used, I wonder if you're mis-interpreting the image.

I think the large, luminous disk is actually the Moon, and the smallest disk is Jupiter - You can just about see some surface detail on it, which you wouldn't if it was one of Jupiter's moons.

I suspect the green disk is an internal reflection of the camera.

[peterbolson]

I think you're right about my misinterpreting it - I hesitated about posting it but I wanted to be sure. It was taken at 00.24 hours. Here are 2 others at 00.19 and 00.27 hours.

It does seem an odd sort of internal reflection though. No scope involved. Just the camera on a tripod. And why should the moon seem so small compared with Jupiter ?

[andrew63]

From memory, about a year ago, i remember observing Uranus and it was only a few degrees from Jupiter - but as stated it is well away now.

andrew

[carldr]

Hmm - Yeah, you have a point about the relative sizes. The Moon is about 35-40 times the diameter of Jupiter (30 arc minutes vs maximum of about 50 arc seconds.) Your image has the larger disc at 5-6 times the size of the smaller.

Do you mean that image was taken in the early hours (00:24) of the 24th? If so, Jupiter and the Galilean moons would have looked like the attached. My previous image showed them as they were of the evening of the 24th.

I still don't know why Ganymede doesn't show, but perhaps it is Jupiter and Callisto after all. I'm sure someone else can help with the interpretation.

But certainly, within a 6 minute time period, you wouldn't see any celestial bodies move as much as the green disc seems to move, in relation to the other objects. Also, in the three images, the green disc always seems to be the same distance up and right from the bottom-right corner as the bright white disc is to the right and below the top-left corner. So I am still sure that's an internal reflection.

[Shibby]

That'll be the Moon, Jupiter and an internal reflection of the Moon, which is quite normal for such a bright (and over exposed) object. You can tell it's an internal reflection because it is always opposite the centre of the frame to the real image.

The apparent diameter of Jupiter is affected by focus & exposure, both of which can cause the small dot to bloat a bit.

It seems quite unlikely that you'd pick up any of Jupiter's moons at a FL of 50mm.

[Clayton]

That'll be the Moon, Jupiter and an internal reflection of the Moon, which is quite normal for such a bright (and over exposed) object. You can tell it's an internal reflection because it is always opposite the centre of the frame to the real image.

The apparent diameter of Jupiter is affected by focus & exposure, both of which can cause the small dot to bloat a bit.

It seems quite unlikely that you'd pick up any of Jupiter's moons at a FL of 50mm.

I agree:)

The Earth's Moon, Jupiter, and a reflection

[peterbolson]

Thanks guys. In retrospect it was a rather stupid question, but as is so often the case with silly questions I've learnt a lot from the answers

[carldr]

The only stupid questions are the ones you don't ask!

[Psychobilly]

The only stupid questions are the ones you don't ask!

Couldn't agree more...

keep on asking away