Iapetus transit of Saturn in 2022 – 30th April 4:00am Australia

[bigmasterdrago]

Hey Phil, for us it is July 18 ~05:30UT during the 2nd half of the event. Too low the first half.

The next one on December 23rd is daylight and below the horizon for use.

Then wait til late November 2035 where we will have good circumstances predawn except the end.

I had to go in and recalculate the times as I had not corrected the software using SPICE. It's a PIA!

The one in 2035 begins ~23:23UT Nov 25   ends ~06:20UT Nov 26 - So mostly below the horizon except the beginning from Brisbane and slightly better at the end of event from SE Texas, up 20°

For the one this year in Dec

[bigmasterdrago]

Had to log out last night due to the worst lightning storm I can recall. Phil, it looked like it hit you after it hit us. If you play a 3 hour loop beginning at 3UT May 1 at https://www.blitzortung.org/en/historical_maps.php, you'll see what I mean. It was 90% daylight for ~1 hour with all the cloud to cloud hits.

I'll have the data for the December 23 transit in a bit. I'm needing a huge load of help from the author of the software I'm trying to use to get it right.

[bigmasterdrago]

Okay. Got the times for the December 22/23 Iapetus event. Ingress is at 4:47 UTC and egress is at 13:32 UTC. So it's entirely below the horizon for me and Phil. For Dennis, Saturn drops below the horizon at 11:57UT. He will have a good chance.

[bigmasterdrago]

Here is some good news... for me and Phil! Dennis mentioned the July 17/18 event but I had bad positions for Iapetus back then. After those getting replotted, I now have the ephem and timing for Iapetus as well as a bonus transit by Mimas.

Iapetus ingress begins at 18:56 July 17 while Saturn is -39° altitude. All times are CDT. Saturn rises for me 3 hours later with Iapetus ~30% into the transit. The transit appears to end at ~04:36 with Saturn 41° up in the SSW.

Mimas ingress begins at 23:56 with Saturn up 23° and ends with Saturn up 35° at 01:06 on the 18th. That's the bonus if I can spot these sats transit.

Generally we get good weather and astronomical seeing that time of year. I have no idea what it will take to visually spot these moons of Saturn as I've no experience as a Saturn watcher. But I'm guessing a good 7" refractor. It will be interesting to start an observing program now.

[bigmasterdrago]

I just looked up its apparent diameter/angular size and at ~0.2", I'm thinking this is not going to be any sort of visual object.

[Dennis]

Here is a http link to a post on the Cloudy Nights Forum with a photo and an animation taken through a Celestron C14.

https://www.cloudynights.com/topic/82216...ry11869008

I'm not sure if you have to be a Registered Member of CN to access it?

Cheers

Dennis

[bigmasterdrago]

Dennis, thanks for passing that. Stunning!

[theskyhound]

I have clearly fixed Iapetus( ahem):

   

I'm providing this purely for entertainment value, because I thought it was really funny! Please don't think less of me for it.

Actually, this is good news. The position is much more accurate. I just need to figure out what's causing the wonky part and we'll be all good.

[PMSchu]

Was it von Newman who said with 4 terms he could fit an elephant & with 5 he could make him wiggle his trunk? Saturn is wiggling Iapetus or something. 

Must be aliens  .

Saturn looks nice.

Phil S.

[Dennis]

So I fixed Iapetus.

Or not. I have no idea why its doing that. And its not even going in front of the planet?

Sorry, Iapetus, you are no longer my favorite moon of Saturn!

I have clearly fixed Iapetus( ahem):

I'm providing this purely for entertainment value, because I thought it was really funny! Please don't think less of me for it.

Actually, this is good news. The position is much more accurate. I just need to figure out what's causing the wonky part and we'll be all good.

Hi Greg

Just FYI, I sometimes use a couple of other well known Planetarium programs and with one of them, one of the fainter moons is always 180 degrees out of place in its orbit, and with the other, the moon seems to remain stationary even when I scroll the time forward in increments of several hours. This tells me that these kind of problems are not easy to grapple with and provide a fix.

Cheers

Dennis