Hi All,

Just a quick note to let you know that I decided to start the New Year with a new blog, which I have just finished setting up.  You can find it at http://astronomymike.wordpress.com.

I've just finished setting up some image galleries there too, so feel free to drop by and pay me a visit .

Happy New Year to you all, and wishing everyone clear skies for 2010!

Cheers, Mike

It's been a long time since my last post as I've busy with my business and things have only just started settling down.  I thought I'd just share this little nightmare I recently had with my primary mirror and hope that it may help other "noobs" falling into the same trap!

I recently purchased a new astronomy camera - an Imaging Source DMK41AF02.AS.  Nice camera and much higher resolution than my old Philips SPC900NC (ToUcam III).  First light for the new camera was not in ideal conditions (poor seeing and windy), but I was determined to try it out as we've had a long period of bad weather (which is still continuing!).  The first images out of it showed a number of quite large dark spots, which I eventually narrowed down to being on either the primary or secondary mirror of the telescope.  On inspection, with the mirrors still in place, I could see a few bits of black crud stuck to the primary. 

Now, I've never had a primary mirror out before, and all the reading I've done on the subject suggests that this is not a good thing to do unless absolutely necessary!  Gulp!  Nervously, following the manufacturers instructions line by line, I removed the mirror.  With the warning voices of those who have gone before me ringing in my ears, I soak the mirror in lukewarm water and detergent and proceed to VERY carefully clean it, rinse it and allow it to dry off.

Let the nightmares begin...

OK, so the mirror is now dry and I place it back in its cell and tighten down the rubber mounts that hold it in place.  The cell is then placed back in the tube and secured.  Collimation is done and all looks good.  Whew!  Job done, and no breakages!    We're good to go, right?  Not quite - I have to wait for a couple of days before we get any clear sky.  Finally I get a break and take the scope, camera and laptop out to image Jupiter - hang on a minute, why can't I focus on Jupiter???  Must be "bad seeing".  Let's try the Moon...OMG!  Why does the Moon look like a big hairy white lemon?!!!  There is a distinct "sinking" feeling in the pit of my stomach as thoughts of scratching the primary mirror surface during cleaning come to mind.  Rechecked the collimation and it's still good.  Spent the next half hour trying (unsuccessfully) to get good focus on the Moon.  Oh dear...grasping at straws I think, "maybe the detergent left a streaky film on the mirror?".

...the nightmares continue...

The next day, the primary comes out again and, on close inspection, there are indeed streaks on the mirror (and the black spots of crud are still attached!).  Yes!  So, the mirror gets an even longer soak before cleaning again and this time is VERY thoroughly rinsed before drying off.  Feeling somewhat relieved that I have "found the problem",  the mirror is once again set into its cell and rubber mounts tightened down.  The cell is placed back into the tube and recollimated and the weather waiting game starts again - this time I am even more anxious to see the result!  A couple of days later I get a very small window of opportunity - it's still very overcast but the high wind is creating very brief glimpses of the Moon.  It takes me several attempts between clouds to get as good a focus as I can.  What the...?!!!  Houston, we still have a problem!  The Moon is still a big hairy white lemon!!!  My heart is really racing now, and that sinking feeling in my stomach just dropped out of my trouser leg. 

...waking from the nightmare...

The following day, I emailed a few people for advice, and one of them sends me a document on "optical aberrations" and suggests I compare what I'm seeing with some of the photos in the document.  Unfortunately, all of the photos are based on images of stars and I've only been looking at the Moon so far, so nothing seems to match up.  I wait for another few days for a break in the clouds so I can get the scope out again and look at a star.  Finally a small hole opens up and I can see a handfull of stars and quickly get the scope out to have a look.  What I see doesn't match anything exactly, but has similarites to the "coma" and "astigmatism" images in the document.  Progressively eliminating the potential causes that they list, I come to the conclusion that the mirror may be "pinched" - this apparently occurs when the mirror is too tight in its cell and causes the shape of the mirror to become distorted.  Given that the mirror is about 1.5 inches thick, I doubt that this is the cause but proceed to remove the mirror from the tube (again!) and loosen off the rubber mounts and check that they are still tight enough to hold the mirror in place before placing it back in the tube and recollimating.  It's several days again before the sky clears enough to check it out, and I'm a nervous wreck by the time it does finally clear.  The Moon is up too, so I grab the scope and focus in...........

...the nightmare is over!!!

There it is!  The Moon is back in all its big, bold and beautiful glory!  Sharp as a tack!  Jupiter and the Galilean moons look great too, and stars are once again pinpoint!  It's late and my wife has gone to bed, but I whoop it up and dance a jig anyway!  I'm exhausted from all the stress and worry that I've caused myself, and the cloud is returning anyway, so I pack up and head off to bed (I slept VERY well that night ). 

That was about a week ago and I haven't been able to get the scope out since and do some imaging.  The only clear night we've had since then was the night I had to give a presentation on Jupiter to the local astronomical society that I joined recently.  They had some viewing afterwards and we had a good look at Jupiter.  By the time I got home it had clouded up again and it has remained that way ever since .  Never mind, my time will come, and when it finally does it'll probably be an all-nighter!

The moral of the story?  Well, I guess one moral could be "don't panic!".  Another could be, if you're not confident in removing, cleaning and replacing a primary mirror - ASK FOR HELP from someone who knows!  And if things start to go wrong, ask for advice sooner rather than later - you could save yourself a lot of stress!

Clear skies to all!

Mike

A couple of nights ago we finally got a break in the evening cloud cover that has been plaguing us for the last few weeks, so I decided to see what all the fuss was about Comet Lulin.  Quite exciting really, as I now have my first "real" scope and I have never actually seen an comet before.  So, armed with a map of where Lulin should be (courtesy of http://www.rasnz.org.nz/Comets/C2007N3.htm), and full of newbie enthusiasm, I headed out to look for my first ever comet.

Ummm...what does it look like?

A little knowledge can be a dangerous thing, and my only encounter with the comet to date has been through John_Buonomo's blogs and animations (if you haven't seen his work yet, you really must do it now - in fact, leave my blog right now and pay him a visit!).  So, expecting to see the same thing as John (on my 127EQ - what an idiot I am!), I start searching around Spica low on the eastern horizon (again I say "idiot"!) with the binoc's.  Nothing!  After about half an hour of fruitless searching I just happened to catch a glimpse of a very faint, light-grey, round "smudge" close to a faint star not far from Spica.  To me, it looks a lot like the globular cluster 47 Tucanae (sorry guys, you can't see that from the northern hemisphere) through binoculars, so I head inside to the PC and have a look on Celestrons' "The Sky" software...ummm, the faint star must be Theta-Virginis and there's Spica, but no cluster or any other object it could be.  Wow!  I must've found a cluster not listed in the software (how do you spell "I-D-I-O-T"?)!  So, back out I go and line up the telescope with my "new cluster", expecting that, like 47 Tucanae, the stars in the cluster will just magically "pop out" at me.  Hmm,...it's now just a larger light-grey smudge - hey Mike, you don't think that this could be <gasp>...LULIN...do you?  Nah...it's not greenish and doesn't seem to have a bright core.  Oh well, I give up - I'm off to bed.

The next day...

I'm still puzzled about the "new cluster" I found last night and have another look at "The Sky" software.  No, I didn't miss anything - there's definitely nothing there.  Maybe I should ask the guys on CelestronLife what it is?  (In hindsight, I'm sure glad I didn't ask !).  Also still puzzled as to the whereabouts of the missing Comet Lulin, I pay another visit to the Lulin map website.  Now let's see - there's Spica, there's Theta-Viriginis (oh, so that's what the Greek letter for theta looks like!), and there's the path of Comet Lulin running right between the two of them!!!  Many expletives bounce around my head and for the rest of the day I continue to kick myself in the arse with my imaginary foot whilst praying for another clear night tonight.

That evening...

Cloud rolled in late afternoon and I just know that I'm never going to see Lulin again <sob>.  About 10pm I step out the door and find that the cloud has disappeared!  Yes, yes, yes!  Grabbed the scope, polar-aligned, and pointed east looking for Spica and my friend Theta-Virginis, knowing that the comet was still close by the latter.  Oh, but wait, they haven't risen yet (spell it with me folks - "I-D-I-O-T").  Ahh, but look, Saturn has!  And the seeing was fabulous!  I have never seen Saturn so crisp and clear - not only that, I actually could make out at least 2 of its moons (I think that I occasionaly caught a glimpse of a 3rd every now and then too).  In fact, the image in my 20mm eyepiece was so clear that I didn't want to go and spoil it by adding the 3x barlow and having to refocus.  So, I tracked Saturn for a bit, had a look at some of the bigger Milky Way objects, and finally Spica rose.  Located Theta-Virginis and quickly found my "new cluster" (aka Comet Lulin) through the binocs again, lined up the scope and hey-presto!  There she was - still a round smudge, but tonight I could easily make out a brighter core.  I tracked Lulin for about an hour and, the further it rose off the horizon, the better I could see the core.  Sadly, the cloud cover started rolling back over then and I had to wait for glimpses of the comet until finally the cloud blanketed the sky for the evening.

Still, at least I can say "found it, seen it, loved it", and next time I'm looking for a comet, I'll know what I should be looking for!

Until next time, take care and clear skies to all!

-Mike

Where did our summer go?

Unbelievable!  Ever since I bought my 127EQ early in the New Year, I seem to have been battling the weather for supreme control of the skies.  Don't get me wrong, we have had lovely warm days, but by early evening high cloud starts rolling in and destroys any chance of a decent nights' viewing.  Still, I'm sure that you northern hemisphere folk are having similar weather problems over the winter and probably having to contend with cold, rain and snow to boot, so I guess I shouldn't moan.

Anyway, for about 2 weeks straight we've had the type of weather above, with the last week being almost solid rain.  However, last night the weather finally cleared!  So I quickly grabbed the 'scope, made a quick list of things I wanted to see (thanks Celestron "The Sky"!) and headed outside.  I certainly wasn't disappointed - the recent rain and cold air flow above combined to make some great seeing conditions.  Here's a quick list of things I managed to view last night:-

• Clouds of Magellan - in the Large Magellanic Cloud (LMC) I viewed NGC 2032 (Seagull Nebula) and NGC 2070 (Tarantula Nebula).  At least I think that's what I viewed!  There's so much to see in the LMC, and I'm still finding my way around, but even if it wasn't those nebulae, whatever I saw in there looked great!
• Just off the Small Magellanic Cloud (SMC) is 47 Tucanae - a globular cluster of several million stars.  Only visible from the southern hemisphere, and I have to say, very, very impressive!
• Omega Centauri (NGC 5139) - a globular cluster, visible by the naked eye, but again very impressive through a telescope.
• Orion Nebula (M42 & M43) - impressive as ever!  I can't help myself - every time I get the telescope out, I have to look at this!
• The Pleiades (M45) - I have to time my viewing of this, as it is in the northern sky and I have to wait until it is between two large (about 30 metres high) trees on our property to view it.  I keep threatening to cut down all the tall the trees around our section, but my wife just let me near the chainsaw!
• Saturn - finally!  After several nights spent figuring out that over-magnifying was NOT the way to go (750x mag on a 'scope with a "useful" mag of 300x acheives nothing!) and that viewing low on the horizon was not a "good thing", I finally got a decent view of Saturn!  Although the rings are edge-on to us at present, it was still a great sight to see, and I even managed to resolve one of its' moons.
• Comet Lulin - I wish!!!  Alas, Comet Lulin should be close to Spica at present, so I patiently waited for Spica to rise, only to find that the Moon (about 3/4) also rose at the same time!  After several attempts to locate the comet through binoculars, I came to the realization that it just wasn't gong to happen, and decided to do a spot of moon-viewing instead.  I have to say that even though I was disappointed about not getting to see Lulin, the Moon was pretty spectacular viewing last night.

That pretty much wrapped up the evening, and I toddled off to bed a happy man.  I awoke to beautiful blue skies and they remained so for the rest of the day, luring me into a false sense of security that I was going to get another "fix" tonight.  Unfortunately the high cloud again started rolling in at about 8pm (it gets dark here about 9pm) and, as I write this, we are completely overcast again.

Ah well, such is life.  Until next time folks - clear skies!  And thanks for joining me.

Mike