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Thursday, April 19, 2012

Astro Setup

The Celestron Nexstar 4 SE is equipped with 'red-dot' guide scope and fitted into the barrel, is a Neximage CCD imager connected via USB to my Macbook Pro 15" laptop for image editing and processing. '4' means the diameter aperture of the scope is 4" wide - this correspond to the the size of the mirror as well.

The bigger the mirror, the brighter and clearer the image will be.  And with that comes a hefty price tag too!!
It is a 'Go-To' mount.  Just punch in a list of celestial objects you want to see and it will slew towards the position of the object selected by you.  But first you must enter the coordinates and details of your location into the scope's handheld computer so that the scope 'knows where it is on the Earth'!  Get it?


I not only have the Neximage CCD to photograph the sky but I also utilise my old Canon Digital iXUS400 camera to take different shots.  The camera is mounted onto a special 'adapter' made for this type of camera where the camera lens is positioned over the telescope lens.


I bought it off eBay for just US$20.00!  But I wish to get a simple and cheap SLR/DSLR body only with controls for ISO and time-based captures for Deepsky Objects (DSO).  This camera can be fitted with a 'T-adapter' for larger cameras to the back-end of the telescope.

It comes in a nice case!



My lens set (6 pieces) which I bought it online on promotional price for only the equivalent of RM403, and this includes 7 planetary filters  In Malaysia one lens costs RM180!






In the future, I would like to get a C8 SGT (8") for some serious astro viewing and photography.  C8 SGT (XLT) Schmidt cassegrain telescope. Go to Celestron.com for more info.


Wednesday, March 14, 2012

Jupiter & Venus Transition.


Who says the number 13 is an unfortunate number.  March 13th is the best of times because after an overcast and cloud-filled skies above me never seemed to open up.  But the sudden appearance of my 'two friends' suddenly said 'Hi' through my gloomy spell.



Jupiter (left), and Venus.  8:30pm


Both continue their journey westward, pulling away 1deg each day now.

The close coincidence of Venus and Jupiter in conjunction, the steep angle of the ecliptic and Venus’ greatest evening elongation keeps these worlds up for several hours after dark – and ensures  a beautiful gathering of worlds in the western evening sky this month. They are well worth getting outside to see.

Bottom line: Venus and Jupiter are in conjunction on March 13, 2012. This is the best evening Venus-Jupiter conjunction for years, as seen from different parts of the hemisphere.  Venus and Jupiter stay out for nearly four hours after sunset. Venus and Jupiter are close throughout the month of March 2012. They are like twin beacons – two very bright planets – near each other in the west as soon as the sun goes down. (Excerpt from EarthSky.org)

Other than Messier and Caldwell objects, running parallel to these are my quest for 'Near-Earth objects'.  Or a layman would say, asteroids and comets.  And not-so-distant away, the imminent hunt for orbiting satellites and other space junk, will not be foreign as before.

So lookout for my posts, as they say, 'will arise from the East' and you know its here!

Thursday, March 08, 2012

Clear Skies Please



I has been 'gloomy' since my last quest ended with that shot on Venus and 'The Three Friends'.
(Read my earlier blogs)  Seeing conditions are poor, as in cloudy and more towering nimbus clouds at times.  Or,..cold, whispy clouds of altostratus, cirrostratus dancing away high where some may call it beautiful.

For now, my gear is sitting on my table....checking, checking and re-checking, warming up for the next clear skies.  The conjuction of Venus and Jupiter will happen next week - 13th March.
Clear skies pleeeeease!





Tuesday, March 06, 2012

How To Open The Nexstar 4 SE

Fig. 1
Fig. 2
Use a small 'Philips' screwdriver to remove your finder scope. Fig.1

















Make sure you mark your screws before removing them using any sort of 'marker' that wouldn't be rubbed off by your fingers.

You would want the same screws to go into the same hole, and the correct tension, hence the 'marker'.
Fig.3
Fig. 2











Also, it makes sense to mark all three screws differently.  You can mark all three screws 1, 2, 3.  I 'dot' mine accordingly.  Fig.3











Fig.4





Then you can proceed to remove all three screws and 2 screws that secures the quick-release 'slider' to the rear housing.  No need to unscrew the screw at the end of the slider. Fig.4







Fig.5

 






Fig.6
Once all the neccesary screws are removed and stored safely, slide out the tube and the rear housing apart slowly and carefully not letting the 'inner tube' touch the body of the scope.  Use your common sense! 














Store and cover the rear cell away safely from arms reach (you do not want it to roll away do you?).

Again carefully not touching anything of the mirror or tube assembly! Fig.6


Fig.7












Hold the tube with the opening facing 'down' so any dust would just drop away while you use the 'puffer' as I called it. Fig.7

If your hands are small enough you could use the soft lens brush to brush lightly away on the 'corrector lens'.  Once again be gentle and use very, very light strokes.

Make SURE your brush is CLEAN and free of particles!!


Fig.8






'Stand' the tube like this (Fig.8) so dust would not enter the tube as you work away on the other part of the telescope.










Fig.9






Now we come to the mirror.  The object is that you don't want scratches on the mirror!  So use light strokes for dust particles that seem to 'stick' on the mirror.

You can use the 'puffer' first to blow away the particles. Fig.10 Whichever way you can alternate between them.



Fig.10

 Use the 'puffer' at an angle to the surface whether its the mirror or the front lens you're cleaning, so dust is removed effectively away from the surface.




A word on using the lens brush, brush on the surface as if you're almost touching it. Remember that you want to remove the particles and not 'pressing' them onto the glass while you swipe away.




Fig.11


Fig.11 At times I would also clean the angled-mirror inside from the lens barrel.  The same goes through the rear of the cell where you'd screw the 'T-Adapter' at the back - remembering to hold the rear cell pointing downwards for the dust to fall through.


Give it a soft and gentle sway of left to right motion to let any residue fall away. A gentle 'shake' would also do the job.



Fig.12
NOTE: For an 'un-opened' Nexstar 4SE

NEVER..ever use a vacuum cleaner's hose and suck dirt from the opening of the rear cell!! Fig.12  I've read from a forum that someone did that and guess what? I did it! Foolish me!

By doing so, all the dust or whatever that's at the back of every corner of the rear cell is going to get sucked into the main tube and get stucked to the back of the 'corrector lens', then you're a goner!!

The suction power will multiply through the secondary tube inside the telescope's main tube.  My heart dropped when I saw my corrector lens was full of dust particles stuck on the corrector lens.  That is how I dared to learn to open my one-week new 'baby' and cleaned it.  I wanted to clean it because of a speck of dirt that I saw on the lens.  Of course I managed to find someone who did open his Nexstar 4 SE on YouTube.

Lastly, I didn't post anything on using lens-cleaning liquids here, especially on cleaning the main mirror.  You shouldn't be touching it anyway!


But I did use some alcohol dropped onto a lint-free soft cloth (camera or spectacle cloth) and folded without any nasty crease on it.  Just straight folds.  I 'puffed' the mirror first to make sure I would not scratch it when I wiped it with the cloth.  And that's it!  I just imagined that I was an archeologist dusting away some precious artifact - that's how you should do it.  With greatest care.

I'd like to remind you again that I only cleaned using the the alcohol twice, only after my foolish act and none after that.  Like I mentioned, you've got no business letting your fingers wander near the mirror, all because the focusing screws are behind that mirror.  Never put pressure on the mirror, or any parts inside the tube and rear cell. 

The Nexstar 4 SE is known for its 'no collimation needed' assurance. So if any of its assemblies are 'off' by your mishandling, then its back to the dealers for adjustments - minus your warranty and plus whatever costs needed!!

Re-assembling is easy enough.  Just reverse the process, carefully as you go along and lastly screw it back to its mark.  Hope my 'foolish' adventure helps.  'Curiosity Kills the Cat.'  Clear skies!!!

 End note: I did checked with the dealers that sold me the scope about my 'dirt', and they say it's nothing to worry about as it wouldn't have any detrimental effects as far as veiwing is concerned.  So no worries!!



Sunday, March 04, 2012

My Precious.

6th February, the end of Chinese New year.

Awesome!

                                                                                        NGC 3242

There it is, the 'bluish' dot near the middle.


 This planetary nebula is most frequently called the Ghost of Jupiter, or Jupiter's Ghost, but it is also sometimes referred to as the Eye Nebula. It can easily be observed with amateur telescopes, and appears bluish-green to most observers. Larger telescopes can distinguish the outer halo as well.[3]


 
This is what its supposed to look like, taken from a 10" telescope.  Be reminded that mine is only a 4" telescope!





Moon Craters






















Out came the moon and I whipped out the telescope, punched in the coordinates of my locality into the handheld computer and away it went - slewing to the moon!  It was a clear night, so forget about shooting the stars.  The Moon is just too bright.