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  #21  
Old 25-07-2018, 08:15 AM
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Thanks for explaining!
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  #22  
Old 25-07-2018, 11:41 AM
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Quote:
Originally Posted by Wavytone View Post
The unfortunate part - for the beginners here - is that it is going to be a very unusually long wait for another one over the eastern states - 2031 !
Hi Mr Wavytone,

According to Occult, we (Easterners) will see a Lunar Eclipse on 26th May 2021. See attached. Not so unprecedented as 'Next Saturday's' but all the same.

Then another 7th September 2025.
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  #23  
Old 25-07-2018, 12:21 PM
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Quote:
Originally Posted by Wavytone View Post
Forget the graze if you live in Sydney/Brisbane/Melbourne/Hobart.

You can forget mag 7 stars even in a scope - I tried yesterday.
You do know what a graze is... don't you? I don't think you do!

The graze I was referring to is of SAO 163510 - see previous map.

This star is occulted by the moon during totality, ONLY for observers south of the red line on the map - the northern limit. The graze occurs at sites along the northern limit. Sites South of the Northern Limit will see a Total lunar occultation (during totality).

As to the visibility or not. Most occultation observers use video nowadays and it's quite common to observe lunar occultations of mag. 7 stars will into twilight. I've been able to read my printed notes without a torch light, while the star is quite visible in the scope. Having said that, it is quite hard to predict visibility during eclipse because the of the colour of the umbra.

And notwithstanding clouds...
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  #24  
Old 25-07-2018, 01:03 PM
Wavytone (Nick)
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Ah actually I do - When I lived in Canberra long ago I was one of Dave Herald’s lot timing grazing occultations in funny places in the countryside. But not since moving to Sydney.
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  #25  
Old 25-07-2018, 01:06 PM
Wavytone (Nick)
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Ah actually I do - When I lived in Canberra long ago I was one of Dave Herald’s lot and times many many grazing occultations in funny places in the countryside. But not since moving to Sydney.

The only significant thing that has changed since then is using a camera to record it...

Still think you’ll be struggling to see this.

Good luck !
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  #26  
Old 25-07-2018, 01:22 PM
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Quote:
Originally Posted by Wavytone View Post
The unfortunate part - for the beginners here - is that it is going to be a very unusually long wait for another one over the eastern states - 2031 !
Hi Wavy,

No lunar eclipse visible eastern states in 2031. 7 total eclipses between Saturday and 2031 including this weeks eclipse. Another 4 visible in 2032/33.

Lunar eclipses of some description occur every year. However some of these are fleeting glimpses eg we might just catch the beginning/end of a penumbral as the moon is setting or rising. Total lunar eclipses occur pretty regularly with some years having only partial/penumbral eclipses(worldwide). For example, there is a total next yea but only visible from the other side of the Earth c Pacific, Americas, Europe, Africa but not here.

2020 is a no total year, 2021 there is a total visible here. 2022 there is a total but we only see the penumbral before moonset.

From any one location, we tend to see two or more sequential total eclipses clustered every 3-4 years. I'm making a broad generalisation here. I've attached a table extracted from Chris O'Byrne's eclipse explorer software showing total eclipses visible from Sydney 2001-2040. Where the text is grey, it means that event of the eclipse is below the horizon at the selected location.

Cheers

Joe
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  #27  
Old 25-07-2018, 04:15 PM
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Quote:
Originally Posted by Wavytone View Post
A CHALLENGE FOR VISUAL TYPES: Here is a technicality about this eclipse which might interest a visual observer:

Yes its the longest this century but in the eastern states disappointing. The time of second contact (5:30) is well into twilight so the moon will basically disappear and won't be much of a sight. To see it properly you have to be much further west - Perth, for example.
It is not the longest in the century: one saros ago (16/17 jul 2000, the very first year of the century) it was longer (1:46 and next Friday 1:43) and was closer to the center of the shadow (1.77 vs 1.72 now).


https://eclipse.gsfc.nasa.gov/LEplot...2000Jul16T.pdf



And don't say "2000 is part of the 20th century as there is no year zero", because there *is* a year zero because there are also 'negative' years (BC). Simple basic arithmetics.
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  #28  
Old 25-07-2018, 04:26 PM
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Interesting list - I was looking at the circumstances - including the maps - on Fred Espenaks site - yes there are some total lunar eclipses in the 2020’s but the circumstances for Australia are less favourable even than saturdays eclipse. And I have rather more faith in Fred’s website.

As I said, a very long wait for a decent one over the eastern states.
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  #29  
Old 25-07-2018, 05:44 PM
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There are more total lunar eclipses visible from the East Coast in the 20s.


The most remarkable is New Years Eve 2029, at midnight the Moon is almost totally eclipsed.


Find the scheme here (times in UTC).
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  #30  
Old 25-07-2018, 08:41 PM
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Take a closer look
http://www.eclipsewise.com/lunar/LEd...2029Dec20T.pdf

There's a huge issue with the date and time and visibility of your prediction. If there's a lunar eclipse on December 20 there can't be another 11 days later. Mr Eclipse is Fred Espenak, who has been running the NASA/JPL eclipse ephemerides for decades.

I know which one I'm inclined to believe.
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  #31  
Old 25-07-2018, 10:33 PM
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Hi Wavy,

Chris O'Byrne's calculator works off the 5MCE (Five Millennium Canon of Eclipses) which was produced by Fred Espenak. The eclipse you referred to is December 20, 2029, not 11 days earlier, but 12 synodic months after the new years eclipse on Jan 01, 2029.

The website you are looking at is expressed in UT, the calculator I used is EST, and the data Skysurfer posted December 31 is expressed in UT. The eclipse skysurfer and I listed is time consistent after converting time zones. He did refer to new year's eve 2029 which I can understand may have thrown you off but the circumstances in his post did clearly state Dec 31, 2028.

All circumstances published in this thread are correct and consistent. No huge problem exists with the predictions.

The list I published only lists total eclipses visible from Sydney. It lists the eclipse even if only a penumbral part is visible above the horizon using the grey text to show sub horizon events.

These lists can be confusing to read. It's easy to make mistakes with dates especially with the UT/EST confusion across midnight. When that change occurs across a year change, it's even easier to misread.

This eclipse and the July 16, 2000 are part of the same saros series 129, a series of very long eclipses.
1964 June 101 mins
1982 July 106 mins
2000 July 106 mins
2018 July 103 min
The 1982 & 2000 events were the longest/deepest of the saros and the eclipses of this series are now getting shorter.

So if you are waiting for a longer eclipse to call decent, you'll be waiting a long long time.

kind regards

Joe
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  #32  
Old 26-07-2018, 12:03 PM
Wavytone (Nick)
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Quote:
Originally Posted by skysurfer View Post
...New Years Eve 2029...
To me that is 31 December not January 1.

Oh never mind let it pass.
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  #33  
Old 26-07-2018, 07:10 PM
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Quote:
Originally Posted by Wavytone View Post
To me that is 31 December not January 1.

Oh never mind let it pass.
I do agree with you that it was a confusing way for him to express it. I would also have thought he meant Dec 31, 2029 had I not already seen the Jan1 2029 in my list. His attachment with circumstances did list it as Dec 31 2028.

I know that all the various people producing interactive maps, circumstances, predictions etc for solar and lunar eclipses have put a lot of effort into getting it all correct and consistent right down to moving from the old Watts lunar limb profile to the much more accurate Kaguya profile so that even limb corrections are consistent.

I trust anything by :
Espenak (mreclipse.com)
Ernest Wright (NASA)
Bill Kramer(eclipse-chasers.com)
Xavier Jubier(xjubier.free.fr)
Michael Zeiler (eclipse-maps.com)
Chris O'Byrne(eclipse explorer calculator)
Dave Herald(Occult software)
and probably quite a few others.

Cheers and clear skies

Joe
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