Lunar Eclipse on April 15th

[ClaireBaire (Claire)]

Hi All,

I'm new to astronomy and am wondering about the lunar eclipse viewing possibilities for Adelaide on Tuesday.

Does anyone know the best place to view "all six minutes" of totality around Adelaide Or will only the Eastern states be the only lucky ones? eg Sydney gets a whopping 20 minutes!

Excerpt from http://astroblogger.blogspot.com.au/2014/04/total-lunar-eclipse-april-15 2014.html (painfully formatted, hope it comes out ok)
City Moonrise Sunset Maximum Eclipse Totality End Eclipse End
Adelaide c 5:48 pm 5:52 pm 5:16 pm 5:54 pm 7:03 pm
Sydney 5:28 pm 5:33 pm 5:48 pm 6:25 pm 7:33 pm

Cheers,
Claire.

[Wavytone]

You're unlikely to see it before 3rd contact because it will be so low on the horizon the fully eclipsed moon is almost impossible to see due to (a) the murky air) and (b) the background sky will still be brighter than the moon.

Not impossible if you had the ideal location and ideal weather, just highly improbable. Good luck trying !

BTW there was a lunar eclipse many years ago in which the sun rose as the moon set fully eclipsed. With the help of refraction it was possible to see both simultaneously for a few seconds, as I had clear air and was observing it from Mt Stromlo.

[ClaireBaire (Claire)]

[QUOTE=Wavytone;1073128]You're unlikely to see it before 3rd contact because it will be so low on the horizon (Thanks Wavy, what about viewing from Mount Lofty - the tallest Adelaide "pimple" reaching the dizzy height of 727m) the fully eclipsed moon is almost impossible to see due to (a) the murky air) and (b) the background sky will still be brighter than the moon (Dang )

Not impossible if you had the ideal location and ideal weather, just highly improbable. Good luck trying ! Still I will try, the weather at least should not cloudy, plus windy 10-15 knots - don't know if this is good or not.

BTW there was a lunar eclipse many years ago in which the sun rose as the moon set fully eclipsed. With the help of refraction it was possible to see both simultaneously for a few seconds, as I had clear air and was observing it from Mt Stromlo (Lucky you )

Claire.

BTW I have a supposedly fast scope f5, why does f15 rule?

[Wavytone]

Ah. OK, Mt Lofty. Dim memories as a kid long ago.

If it is blisteringly clear - and I mean 10 out of 10, you might just have a chance of seeing the moon while in the umbra.

But - here's the catch - if you don't know exactly where to look you'll easily waste the 6 minutes trying to find it.

I know its a bit late now - the night before - but if you can go there and set up a telescope TONIGHT correctly aligned on the south pole, and place a marker to set the azimuth of your mount (due north or south) on a fence or building this will help you get set to find it tomorrow in daylight.

Why f/15... my first scope was a beautiful 4.25" Thomas Cooke refractor made around 1880 with a superb clockwork mount made of phosphor bronze - a 6" diameter worm with 1440 teeth and circles that read with verniers to 1 minute of arc. Yes you had to use an atlas, and do some maths. The views of the planets through this were exquisite and none of the scopes I have used in the past 40 years have dimmed this. The scope is still in occasional use - it belongs to a private school. These days I have an f/15 Maksutov, next best thing. Maybe in retirement (I hope to move to Bright in the high country in NE Victoria) I will be able to set up a similar scope again, just for fun. A 12"-16" dob of course might be more use but I always have a soft spot for long refractors for planetary observing. While work beckons I am stuck in Sydney where observing is definitely a low priority for a host of reasons - starting with crap weather.

[ClaireBaire (Claire)]

Originally Posted by Wavytone

Ah. OK, Mt Lofty. Dim memories as a kid long ago.

Originally Posted by Wavytone

Hi Wavy, thanks for your time so far. I hope you don’t mind a barrage of questions?
If it is blisteringly clear - and I mean 10 out of 10, you might just have a chance of seeing the moon while in the umbra. But - here's the catch - if you don't know exactly where to look you'll easily waste the 6 minutes trying to find it….. correctly aligned on the south pole, and place a marker to set the azimuth of your mount (due north or south) on a fence or building this will help you get set to find it tomorrow in daylight. I have only a 5” Dobsonian, but it nudges easily (if a little clunkily). A check of Stellarium around 5.50pm tonight says azimuth will be about 101 deg. I will use my compass and cross my fingers. To be on the safe side I am taking a quick trip to the “pimple” this morning to check out the lay of the land – there is an eastern view from mount lofty house. Failing that, it will be out near Murray Bridge. It is not so much whether I succeed at getting a great view it is the learning curve that I am after. So far, with all of 2 months astronomy experience under my belt, the learning curve is steep but fascinating.
Why f/15... my first scope was a beautiful 4.25" Thomas Cooke refractor made around 1880 with a superb clockwork mount made of phosphor bronze - a 6" diameter worm with 1440 teeth and circles (sounds like a beautiful smooth movement unlike my little dob) that read with verniers to 1 minute of arc. Yes you had to use an atlas, and do some maths (hmmm, perhaps this will come for me, since I have no computer to do it for me). The views of the planets through this were exquisite and none of the scopes I have used in the past 40 years have dimmed this. Was it the lenses that made the views so good and are our comtemporary lenses crappier (even with coatings etc). The scope is still in occasional use - it belongs to a private school. These days I have an f/15 Maksutov, next best thing (I looked thru a 70mm mak-cass spotter at the Australian Geographic shop, but was put off by the dim view – and yet I sometimes think my reflector and binoculars are just too bright and starry/spikey – in your view is all this reduced using a mak?) Maybe in retirement (I hope to move to Bright in the high country in NE Victoria) I will be able to set up a similar scope again, just for fun (when we are young and own something beautiful and expensive, it’s hard to forget) A 12"-16" dob of course might be more use but I always have a soft spot for long refractors for planetary observing. While work beckons I am stuck in Sydney where observing is definitely a low priority for a host of reasons - starting with crap weather.

…. I want to chuck the city and go and live in outback SA in the dry summer, and for chilly winter I want an observatory with a self-cleaning, highly polished, glass dome ha ha - pipe dreams lol.
Hope I haven’t bored you. Cheers, Claire.

[Wavytone]

Hi Claire, no... It's always nice to see another developing a growing interest in the heavens. That first scope was a half-size twin of the original Oddie refractor at Mt Stromlo, and used for site surveys before it was donated to the school somewhere around 1930. The objective was in coated of course and produced a textbook - perfect diffraction pattern at high power. Your 5" dob probably has about the same light grasp, but shorter focal length.

[ClaireBaire (Claire)]

Originally Posted by Wavytone

Hi Claire, no... It's always nice to see another developing a growing interest in the heavens. That first scope was a half-size twin of the original Oddie refractor at Mt Stromlo, and used for site surveys before it was donated to the school somewhere around 1930. The objective was in coated of course and produced a textbook - perfect diffraction pattern at high power. Your 5" dob probably has about the same light grasp, but shorter focal length.

My 5" dob unfortunately has no discernible diffraction "pattern", just blurry, wavy lines as I move. I think it could be because of the 6mm thick secondary holder arm.

You were right, I could not see the moon rise at all on Tuesday. At about 2 mins past six I saw what looked like a piece of white cotton hanging in the blue sky which I ignored at first because it was quite high above the horizon. It was my father who recognised it. Together we watched the earth's shadow slip away, as the crescent deepened into a bright golden colour and the opaque "dark side" glowed a little so that we could see some of the darker detail. And the full moon cast dark shadows on the ground.

Claire.

[Wavytone]

As it leaves the penumbra you'll see the brightest possible full moon. One interesting aspect of the lunar regolith is that it's reflectivity is maximum on the axis sun-moon, and falls significantly at off axis angles. Even just a degree or two off axis (as with a normal full moon) makes a significant difference.

[ClaireBaire (Claire)]

Originally Posted by Wavytone

As it leaves the penumbra you'll see the brightest possible full moon. One interesting aspect of the lunar regolith is that it's reflectivity is maximum on the axis sun-moon, and falls significantly at off axis angles. Even just a degree or two off axis (as with a normal full moon) makes a significant difference.

That's interesting, there were no dark moon shadows last night. As always, I have to scoot to the books or wikipedia when I read one of your posts - they are great motivators! The moon is the only object I can see in detail - with my little dob. Looks like I need an f/15 refractor with a text book perfect diffraction pattern (sigh).

[Wavytone]

Originally Posted by ClaireBaire

TLooks like I need an f/15 refractor with a text book perfect diffraction pattern (sigh)

Haha no, not really, next best thing is a maksutov - my main scope is a Skywatcher 180mm (7") f/15. This does well enough on the moon and planets.
I have a 102mm ED refractor, f7 which is optically good but the Mak is better. I also have an Intes micro Mak, 7" f/10 but I find the Skywatcher is still better at high power.

Other choices... A long Dobsonian with a good mirror, say 8" f/8 or 10" f/7, or a Meade 10" ACF or Edge HD.

[ClaireBaire (Claire)]

Originally Posted by Wavytone

Haha no, not really, next best thing is a maksutov - my main scope is a Skywatcher 180mm (7") f/15. This does well enough on the moon and planets.
I have a 102mm ED refractor, f7 which is optically good but the Mak is better. I also have an Intes micro Mak, 7" f/10 but I find the Skywatcher is still better at high power.

Other choices... A long Dobsonian with a good mirror, say 8" f/8 or 10" f/7, or a Meade 10" ACF or Edge HD.

Looks like there is quite a bit of searching to do to find a good slow scope in Australia. I can get an f/9, 8" dob from OPT Telescopes in the US (the US has everything! and far cheaper than here) for US $995 but with $400 min shipping cost, then I will have to pay customs to our govt on the cost plus shipping! and on top of all that I will have to pay gst. Too depressing to do the calculations. But the search is on.. until, that is, I have done too many cartwheels, gone around in too many circles and chased after too many wild gooses LOL

[Wavytone]

OK... this is where the choices thin out. Essentially the cheap fast dobs are a plentiful, as you know. For lunar & planetary the choices come down to:

a) opt for a longish refractor, ideally about f/9. Hard to find these days as most refractors as made for "imaging" and are f/7 or less. An aperture of 102mm isn't great for a visual observer and 125mm isn't much better. 150mm defectors are expensive - and heavy. The second problem is how to mount one (also expensive).

b) A DIY long dob, with a primary say 8" f/8 or 10" f/7. There are a few ways to acquire this kind of mirror - order one from a local source (there are a few mirror makers here) or say Zambuto in the US (long wait); watch for one secondhand on CloudyNights and be prepared to pay whatever it costs to get it here - and take a complete guess on its quality; or make one yourself.

Either way won't see much change out of $1k for the mirror, and you still have to make the rest to match. Can be done, but not cheap. There's also at least 1 here on IIS that might make a scope to order if you are patient.

c) Buy a catadioptric scope - a Meade/Celestron f/10 SCT, or a Maksutov (Skywatcher, Saxon, the Meade 7" LX200 Mak, Intes, TEC, or Questar). Optically not quite as good as a long dob, but a lot more compact and far more manageable when it come to handling, storage, transport and mounting. A fair compromise and these can be found secondhand.

A few of the smaller Skywatcher 6" make have come up for sale here on IIS, but I haven't seen a Skywatcher 7" f/15 or a Saxon 8" Mak advertised on IIS, which suggests those who have them are keeping them.

d) Serious DIY territory: two-mirror or three-mirror schiefspieglers, I leave it to you to google what these telescopes are. Typically f/20 to f/23, these are strictly planetary-only monsters with 2 or three mirrors arranged to have no central obstruction. The downside is you have to make one of these entirely yourself. Barry Adcock in the ASV used to have a 12" schiefspiegler that gave exquisite images, long ago; what has become of this now I have no idea.