occultation

[JJDOBBER79]

Hi all,
Apparently a lunar occultation of saturn is going to take place at 9am on Saturday the 22nd of feb. How much of this will be visible? Would be a great sight if it is doable. I guess the objects themselves will be ok, I have no trouble seeing the moon or saturn. Its the 9am part that worries me. :confused2:

[mithrandir]

There are a couple of threads on this. See http://www.iceinspace.com.au/forum/showpost.php?p=1051847 and http://www.iceinspace.com.au/forum/showpost.php?p=1055206

For Lismore it starts at 09:49 with Saturn a bit north of west at altitude ~44 degrees and finishes at 11:00 with Saturn at ~30 degrees.

Any of the planetarium programs will visualise it for you.

[Blue Skies]

With the Moon as a reference point you will be surprised how easy it will be see Saturn, especially in the telescope.

I remember well a daytime occultation of Jupiter about 10 years ago, around 11am in the morning. Because of the Moon, it was easy to see Jupiter naked eye! But with Saturn being a bit fainter it might be more of a challenge.

[DaveGee]

Good question. I'll tell you Saturday afternoon!:rofl:

Just be careful of the start time. It all depends on your location.

For me in The Blue Mountains:
D = 2014/02/21 23:01:58 UT (= 22nd Feb @ 10:01:58 am)
R = 2014/02/22 00:09:47 UT (= 22nd Feb @ 11:09:47 am)

I've not observed a planetary lunar occultation, but it shouldn't be too hard. The Moon and Saturn will be in the west and the sun of course will be in the north east. So best if you setup on the west side of a building (with a view to the west) and keep the scope in the shade.

The disappearance will be at the sunlit limb, and the reappearance will at the unlit limb, which of course will be invisible, so Saturn will reappear in "fresh air" so to speak.

For video observers, a deep red (Wratten 25) or an IR-pass filter should darken the blue sky nicely.:thumbsup:

Here is a movie of a similar event...
http://www.youtube.com/watch?v=EA_cyrjiRs8

[OzStarGazer]

I assume it will be difficult to watch the occultation with a small telescope? I can see Saturn quite well in the darkness, but it is small and I am afraid I won't see much during the day...

[JJDOBBER79]

Thanks for the info. And thanks for the exact time Andrew. Hey oz, the abc science guy reckons it should be easily visible with binos or a small scope.

[Pinwheel]

I'm at-
Latitude36° 39' 18" S
Longitude142° 51' 54" EWill it even be visible & if so what time should I try?

[mithrandir]

Doug, for you it's starting at about 09:48 AEDT and ending at about 11:01.
At start the moon will be about 15 degrees north of west (Az: 283deg) and about half way to the zenith (Alt: 45deg) with Saturn at about the 1 o'clock position with regard to the Moon.

Sydney's weather isn't promising, and I've got a lovely new ASI120MM and Atik EFW2 filter wheel I want to test out on the occultation.

[OzStarGazer]

Thanks! Thinking about it, I am a bit worried because I have a collapsible dob. The event will be in the West, the sun in the East, and my secondary mirror will point at the sun (maybe, I am not sure, but it will point East). I am not sure if it can be dangerous?
Otherwise I could just try with my camera and use the scope in May.

[Pinwheel]

Thanks for the data I'll give it a go. My new 12" is due today so it should be set up in time.

Cheers

[OzStarGazer]

VERY thick clouds here.... :(

[pfitzgerald]

Same here in Melbourne.

[JJDOBBER79]

Worst clouds in a month here. Maybe next time

[mithrandir]

In the last hour it has cleared here. Can't see Saturn in my 11x70s. There might be time to set up the scope before it starts.

[doppler]

Clear sky in Mackay at 6.00am but sea cloud rolling in now... it will probably clear after the occultation is over. I did catch a look with 60 x 12 binoculars in the same FOV as the moon but that was just before sunrise.


Update, It is visible in my 102mm f7 refractor....just not easy to find but should get easier when it is closer to the moon.


Rick

[Pinwheel]

Full cloud cover here in the Wimmera no holes in the cloud. It's 9.10 am and not looking good.:( It's due to start here at 9.48 am.

[mozzie]

kids cricket had a cancelation so home for this and hell the clouds are thick..praying for a sucker hole in around 30 mins will be nice

[pw]

Clouds are cleared around the moon here in Melbourne, but I can't see Saturn yet. Checked with 8x42 binocs and my 8" dob, moon is in clear view and Saturn supposed to be very close.

[CJ]

Near as damn it complete cloud cover here on the Sunshine Coast. Boo!

[h0ughy]

well I managed to find the moon get focused and now clouded.

edit here is the focus shot complete with moate at 9:05am

[pw]

Same here H0ughy, big dark clouds across now, but they're moving quickly so may get a clear patch. (Or rain.)

[mithrandir]

Ditto. :(

[OzStarGazer]

No hope here.
Just for fun, I am watching it in Starry Night. :(

[38degsouth]

10min gap in the cloud here in SE Melb -a very rushed unlevelled dummy star align with the lx90, with a reclamp on the moon. Hey I see it! Not bad considering it was drizzling here 20mins ago, and it looks like it will be again very soon, with full cloud down to SW horizon at the moment... First time I've seen Saturn during the day :)

[pw]

Big clouds now, probably won't see it, but watching in Stellarium on laptop.

[mozzie]

heavy clouds still here...
sky safari will be the only way here bugger.......

[bones]

Clouds clouds go away, come back in 2 hours today. Was all ok here on central coast nsw till about half hours ago. Clouds now rolled in - big slow moving sucker. :(
Hope someone got clear skies
Tony

[h0ughy]

wow wasn't I lucky. it cleared with 3 min to go now clouding again, well it just needs to be clear around 11

[mozzie]

what a great sight!!!!!! on sky safari :shrug::lol:
lets hope the clouds clear in 45 mins

[OzStarGazer]

:eyepop::lol: Wow, just wow!

[mithrandir]

:rofl:
10 mins before occultation start Moon was clear.
cloud
10 mins after start moon was clear.
Frustrating hobby chosen have we..

[pdthomas23]

Some showers here in Melbourne.
Hung the washing under the veranda and then noticed it clearing again.
Moved the scope back out onto the lawn and had a look.
There it was!
Saturn (rather faint) right next to the Moon!
About 9:45 am at that stage.
Raced inside to get the kids, the laptop and the USB eyepiece.
But too late.
Saturn had disappeared behind the Moon and then the Moon disappeared behind clouds.
Fingers crossed for ~ 11 am.

Peter Thomas
Oakleigh

[bones]

Hi ozstargazer. Well done. Where are you located? What setup did you use? Also did you use a filter?
Bones.

[OzStarGazer]

Oh, that is just a screenshot from Starry Night. Too many clouds for real viewing here. :(

[bones]

Hi ozstargazer, that's cheatery. Still conditions no good here. Cloud everywhere.Try again for the next one in May.
Bones

[glend]

I saw it, no problem, just used a red filter on a 15mm Superview EP with my big dob.

[OzStarGazer]

Saturn just reappeared....

[OzStarGazer]

The one in May is in the evening and in a very good location for me (perfectly visible from the beach). Fingers crossed!

[Astroman]

I only managed one pic of Saturn near the Moon, but about 10gig of video of Cloud....

[mozzie]

complete cloud out

oh well next time ;)

[sharpiel]

When in May is the next one? Any one know the disappearance/reappearance times for Sydney for it?

[38degsouth]

The re-appearance was completely clouded out from here in Mordialloc (SE Melb). I consider myself very lucky to have observed anything at all this morning. A small break in the clouds allowing me to see Saturn adjacent to the moon for a few minutes approx 15min before the occultation began.
I look forward to reading posts/seeing photo's from those that were able to observe it ;) Regards, Dean

[OzStarGazer]

http://www.abc.net.au/science/articles/2014/01/29/3932747.htm
There is even another one in August! So 3 this year.

[Pinwheel]

The sky completely cleared 11.20am but the occultation finished 11.01am. :shrug:

[Rob_K]

Bit of a stuff-up here. First up, Saturn wasn't visible through 10x50 binocs even quite close to the Moon. Went with the webcam and was getting Saturn very faintly. Then in a total brain-fade I decided to insert a Barlow a couple of minutes before the occultation - missed the whole thing while I was trying to find Saturn again & fiddling with focus!

Wasn't confident at all for the re-appearance as Saturn had been extremely faint in the live view and the seeing had gone to rubbish (transparency was cracking!). And I wasn't tracking and the mount motion is jerky. Nonetheless gave it a try and did get a roughie.

Attached are a pic of Saturn closing in on the limb, and another of it re-appearing on the darkened limb. Ah well, good practise for the next one... :P

Cheers -

[tonybarry]

There was considerable interest in this occultation of Saturn in our local club (WSAAG), and four members attended UWS Nepean Observatory from 8am to setup and if possible observe the occultation. There was a 12" Lightbridge with several eyepieces and a polarising filter; a 10" LX200 GPS, and an LX90-10 with a Flea 3 camera.

The weather was particularly dodgy, with some large patches of blue sky that came and went in quick succession, along with a lot of cloud and some glare.

Alignment of the Goto scopes was done using terrestrial references (level and north) and this was good enough to get tracking on brighter objects (the Moon, Rigel Kent, Saturn).

However the target planet was invisible visually, and only with some serious histogram expansion was it visible in the camera using an IR pass filter and a gamma of 2.5. The clouds obscured the Moon for the disappearance, and an inconvenient tree on the UWS property threatened the reappearance. The scope / cam was moved but tracking was not able to continue and the reappearance was not observed either.

The occultation was therefore not observed.

None of the communications (in AS&T, or online) made much mention of the difficulty of the observation, and in my opinion, observation of this occultation was not possible due to the lack of contrast of the target against the bright sky. It was however a valuable lesson in what can and cannot be done.

Attached is one small cropped image of Saturn at 9:35am between breaks in the cloud, and a shot of the terminator of the Moon at the same focal length (2500mm). From left to right, the three craters are Arzachel, Alpetragius, and Alphonsus. The improvement in contrast is due to the relative magnitudes - the Moon is mag -6 (apx) while Saturn is mag +0.6 (and Titan, the brightest moon of Saturn, is mag +9).

It is safe to say that this represents the most challenging occultation I have attended.

Regards,
Tony Barry

[seeker372011]

Tony

I was heartened to read your post..it wasn't me then completely at fault

Through a break in the cloud I attempted to view the occultation with first 9 x60s and then 20x80s but had no luck at all.
Clouded out totally by 11 so by the time I had a telescope set up it was pointless...

[Rob_K]

Hmmm, maybe my shots aren't such a stuff-up after all... :shrug: Haven't seen any other shots of the re-appearance yet but Colin Legg got some crackers of the disappearance.

Cheers -

[tonybarry]

Hi Narayan,

Rob H tried a lot of different things with the 12" lightbridge, but Saturn was invisible visually. The clouds and the glare were killers.

Rob K, your image is the best I have seen. Much better than anything we could put on here.

Regards,
Tony Barry

[Rob_K]

Thanks Tony. Hope Colin posts his - he did a timelapse of the disappearance and it is amazing. Detail is superb.

I too was disappointed in not seeing anything visually. At one point I was weighing up whether to view visually through the scope (4.5") or use the webcam - glad I went with the webcam, after reading your post.

Cheers -

[h0ughy]

my results http://www.iceinspace.com.au/forum/showthread.php?p=1060139#post106013 9

[doppler]

I got this shot just before 8 am in Mackay, it was visible though the eyepiece of my 102mm f7 refractor, but not visible with binos, a lot fainter than a daytime jupiter. It clouded over again after this. Tried a few different exposures but it only just showed on a couple of shots. I think that light gathering capability was of no advantage on this event.

[Suzy]

It was wall to wall cloud here in Brisbane so I missed it too. Tho from what you said Tony, it sounds like this would've been out of reach for my 10" scope even anyway. :sadeyes:

This is the incredible timelapse taken by our Colin Legg that Rob K was talking about.....



http://vimeo.com/87319245

[tonybarry]

Hi Suzy,

The 10" would have done the job if the sky was clear and without glare (= thin cloud). The situation is an extreme example of light pollution, and aperture is a known mitigant of light pollution. A red filter or an IR-pass filter (for a camera) would have made it better.

Colin Legg's excellent Vimeo movie shows what can be done, if the clouds co-operate. Thanks Suzy for posting the link

As it was, we were pretty well outgunned by the weather, but there's always a next time. For us here in Sydney, that's 14th May at about 9pm.

Regards,
Tony Barry

[doppler]

Saturn was easily visible in binos and 102mm refractor here in Mackay at 6.00am, just on sunrise but near on invisible by 8.00am. WA had the advantage of the early occultation with more contrast in the sky evident in the images and video taken in WA. I think that saturn is just too faint for full daylight viewing. Looking forward to may 14.
Rick

[Dhufish]

Hi all,

Here in Perth we had light clouds but as they moved through still allowed visibility of both ingress and egress. I had my 10 inch reflector and had no problems seeing Saturn in the early morning light.
I did not use any filters and had no webcam setup.
I did take a picture before occupation with my phone to MMS others, but as it is an older non-smart phone, I do not know how to get it off to post here.
If some one wants to PM me I can text it to you to post.

It was great to watch and fantastic to see Saturn "appear from the blue".
I could even follow it for a while after.

Matt.

[Quoll]

Being a newbie to astronomy the occultation of Saturn was something I was really looking forward to and it didn’t disappoint. What a magnificent view seeing it so close to the moon -fantastic! The image is still imprinted in my mind.

There were clouds drifting around the moon just as Saturn was disappearing so I missed seeing that last final moment, but I managed to get many clear views of it with my 8” DOB when it was really really close to the moon.

After Saturn disappeared I went in for breakfast and then came out again for it’s re-emergence (what a civilised activity astronomy is!). It was getting very bright now with the sun up but I managed to make out Saturn as it re-emerged amid all the glare. Within minutes it became quite difficult to keep watching as the sun was up now and there was lots of glare which made Saturn look devoid of colour. Roll on May for the next one!

As I said, I’m a newbie and a bit confused about the occultation. Everything I read says “the moon passes in front of Saturn”. But when you’re viewing the actual event common sense says that it’s “Saturn passing behind the moon”.

Saturn was east of the moon when it disappeared and west of the moon when it reappeared which seems to suggest it’s Saturn moving rather than the moon. If it was the moon moving then common sense says it would have to be moving west to east across the sky which is of course the opposite direction to what it is actually moving.

Am I missing something?

[mithrandir]

Bill, "the moon passes in front of Saturn" is the right way round. During the occultation Saturn moved a fraction of an arcsecond relative to the stars, while the Moon moved 2'11" in RA and 2'42" in Dec.
As not seen in Sydney due to cloud.

[axle01]

Looking at this site it looks like we won't be able to see it here in Townsville in May.

http://www.lunar-occultations.com/iota/planets/0514saturn.htm

Al

[Quoll]

Thanks Andrew. I've still lots to learn.

[N1]

Tried to observe from South Canterbury with the 60mm refractor - no luck. Contrast way, way too low, as was the moon itself. Agree with Tony - just about impossible to observe during the day without major equipmentation. I take my hat off to those who managed to get an image, or even a glimpse with the sun up. :prey2:

[mithrandir]

With a quick approximation in CdC I'd say the line through Middlemount and Gladstone gets a graze, so you'd need to be south of that. Quite a drive.

[axle01]

Yeah just what I thought and I think it is a Wednesday evening so looks like I will miss it again.

Alan

[doppler]

I am in Mackay so a graze will be fine with me... hopefully in the same field of view of my 8" f6

Cheers Rick

[OzEclipse]

Alan,

Don't worry, Townsville will get a great view of the Saturn occulatation on August 4. Rings begin disappearing behind a dark limb at 1108UT.

Joe

[mithrandir]

CdC says for Mackay it's a miss by a bit less than 3 arcmin.

[Suzy]

Ah, I see. Many thanks Tony for the explanation. I'm so happy to hear that I have hope yet. I have a red filter so I'll take your advice and give it a try. :)