Uranus and moons – view/photo opportunity 4th Oct 2009

[Dennis]

Hello,

I was just looking in Starry Night Pro Plus 6.3.6 at Uranus and his moons and noticed a good opportunity to image and/or perhaps view the brighter moons on 4th October 2009 from around 8:00pm (AEST) onwards.

The attached screen copy shows their positions at 8:00pm and I think the separation increases over the next few hours as Uranus gets higher. At 9:00pm Uranus is at some 56 degrees altitude.

Cheers

Dennis

[Kevnool (Kev)]

I sure hope your going out tonight to capure an image Dennis.
Heres clear skies to you.
Cheers Kev.

[kinetic (Steve)]

bump

No luck here tonight Dennis, clouded in

Thanks for the heads up though, this is on the
to do list.I hope others get a go at it.

Steve

[kinetic (Steve)]

Well I'm glad I persevered, I managed to get the bugger!

Clouds spoiled the view until about 11:00pm and then I was able to
get this set.
DSI pro II at Newt focus on my 12".
I have attached 2 shots. (dustbunnies everywhere!)

First is a crop of the main result of a 5 sec stack, Uranus itself
overexposed.
Second shot is a 2x enlargement with contrast adjustment and
Uranus superimposed over it. The planet shot is a stack result
of 0.0005sec exposures to get the disk size.
Also pasted on this image is the satellite arrangement from
Starrynight backyard for local time Adelaide.
Miranda is a bit out of position when I hover the SNBY layer over
the result.

Thanks Dennis! I hope you got something?!

Steve

[Dennis]

Hi Steve

Well done and top marks for persevering despite the local conditions. We were clouded out in Brisbane so I didn’t get an opportunity to image this event. I almost fell off my chair when I saw your results as was ready to throw out all my Barlow’s, PowerMates and Extenders!

I compared your image to SkyTools and if my interpretation is correct, I think that you may have your 2nd (cropped) image “upside down” compared to the SNP inset?

What put me onto it was the separation between the moons – they didn’t look quite right. So, I took the liberty of comparing your image to SkyTools and annotating it with what I thought were the moons, reference stars and an “asterism” in an attempt to get the correct orientation.

You picked up on this yourself in terms of Miranda’s position discrepancy – truly these types of images are quite difficult to interpret!

What do you think?

Cheers

Dennis

[kinetic (Steve)]

Yep Dennis, you seem to be right eh.
Hmmm...I will tell you my haphazard process :

I aligned the DSI so the field was West at right, South at
top.

Took the frames over the next half hour.
Stacked the result.
Loaded SNBY and oriented the field so South was at top.
Took a cut and paste over to Paint shop.
Resized the stack to 200%
Resized the SNBY crop to fit the satellites span.
HMMM....orientation didnt seem right.
I couldn't work out where I had lost my North/South in the above.
Scratched my head a few mins
Resigned myself to maybe I got North south wrong somewhere.
Flipped the Stack....hey now it fits but Miranda is wrong?

Shrugged my cold , acheing shoulders....and did the paste.
Very scientific eh?

thanks mate for the clarification.

Steve

[Dennis]

Hi Steve

Thanks for the explanation and clarification; identifying these objects can still be quite challenging even with all the software tools at our disposal.

It was interesting to read that you align your CCD to match the field, as with my ST7, I have little choice. I am forced to orient it with cables down, as cables left or right imbalance the system and cables up prevents me from accessing the finder scope, which sits on a fixed stalk on top of the OTA.

Great results none the less; recording the faint moons of these more distant planets is quite a thrilling achievement.

I’d previously overlooked Miranda as SkyTools does not show it. It wasn’t until I upgraded SNP to 6.3.6 yesterday that I looked at Uranus, so Miranda is now on my to do list. Weather and orientation permitting that is.

Cheers

Dennis

[Kevnool (Kev)]

Good on ya Steve for stepping up and imaging Uranus and its moons.
Great images.
Cheers Kev.

[kinetic (Steve)]

Thanks Kev, Dennis.

Dennis does your SNP give mag estimates for the satellites?
All I get in SNBY is mag 16.52 for all of them.
I'm sure that can't be right. there must be some difference ?

Steve

[Kevnool (Kev)]

Iras satellite mag 2.6 on SNPP 6.3.6.
All mags are different.
Cheers Kev.

[Kevnool (Kev)]

All Uranas satellites are different mags as well.
Cheers Kev.

[Dennis]

Originally Posted by kinetic

Thanks Kev, Dennis.

Dennis does your SNP give mag estimates for the satellites?
All I get in SNBY is mag 16.52 for all of them.
I'm sure that can't be right. there must be some difference ?

Steve

Hi Steve

My SNP 6.3.6 shows:
Titania 13.94
Ariel 14.37
Umbriel 15.02
Oberon 14.15
Miranda 16.52.

It only appears to show the magnitudes of the moons of Uranus if I hover the mouse over each moon in turn; I cannot find a list or display magnitude option?

SkyTools also does the same in its “interactive Atlas” although it only displays the 4 brighter moons. However, SkyTools does have an “Object Information” panel which displays magnitude and separation details for the 4 moons on an information panel.

Cheers

Dennis

[kinetic (Steve)]

Thanks Dennis.
Mags noted for future night(s) reference.

I'm up and running tonight as well, have 2 sets in the bag
separated by 1/2hr so far....dodging cloud again.
Seeing is slightly better tonight and touch wood I may
get enough for an animation.

Steve

[kinetic (Steve)]

Tonight's image , 1 of 4
I also made an animation showing one day of
travel against the background stars using yesterday's result.
Easy to eliminate stars as possible satellites this way

Steve

[Dennis]

Hi Steve

Nice work! Chasing these moons of Uranus can become quite addictive huh!

I think (?) that you have recorded Oberon, Umbriel & Titania. The “double” star just above the Oberon candidate doesn’t appear in SkyTools although there is a 12.4 mag star shown in The Sky?

Cheers

Dennis

[kinetic (Steve)]

Yep Dennis, you're right I reckon.
I'm now comfortable with the FOV in SNBY and orientation.
I get the same.
The double star you mention doesn't show in either SNBY or
Cartes with my Tycho 2 plugin activated (stars to mag 12 or 13 I think)

I'm gonna try some colour next with a DSI II mono / DSI II Colour
collaboration.

No moon animation....I only got 2 useful stacks, one at
10:00pm and one at 10:30pm local time.
The 11:00pm and 11:30pm results haven't got enough cloud
free and pinpoint subs to get a noise free smooth stack.
Another night

Great fun

Steve

[kinetic (Steve)]

Ok,

Enough useable frames to make a 1.5hr animation.
A bit noisy and lots of wrong levels!

Steve

[Dennis]

Hi Steve

Nice work! Just love the photo of Dad & Daughter, all rugged up in the control room in the previous post!

I’ve found that imaging over some 3 to 4 hours at long focal lengths can reveal the motion of some of the faster moving moons. The biggest impediment to shooting for a few hours, apart from clouds, is the dreaded mount flip required, when Uranus crosses the meridian.

Cheers

Dennis

[kinetic (Steve)]

Last night was a pretty good arrangement again Dennis
but Miranda was elusive again

result attached with 400x overlay and SNBY positions.
Titania, Ariel and Oberon I think captured.
Yep the GEM flip is at a very bad time Dennis

Seeing was pretty good last night.

Steve

[Dennis]

Nice work again Steve. Miranda is on my to do list but when I set the time step to 1 day in SNP, there didn’t appear to be a nice line up for the next few days. Oct 13th looked promising followed by Oct 23rd.

What’s the focal length of the 12” by the way?

Cheers

Dennis