- “Any intelligent fool can make things bigger, more complex, and more violent. It takes a touch of genius — and a lot of courage — to move in the opposite direction.”
- “Imagination is more important than knowledge.”
- “I want to know God’s thoughts; the rest are details.”
- “Weakness of attitude becomes weakness of character.”
- “Science without religion is lame. Religion without science is blind.”
Archive for the 'Noteworthy' Category
It’s so interesting to disassemble a telescope especially those have a very precise and big gears. I’ve disassembled my computer since I was 8 and 8 years later I disassembled my LX90. I will tell you how to do so step-by-step. However, take it at your own risk, I will not responsible for any damage done to the telescope. I suggest that you read all the procedures before you do anything. If possible, read one more before you start and it’s advisable to print this article with you or leave your monitor on when you are doing your work.
In the Part I, I’m going to tell you how to disassemble the corrector plate. The photos below are clickable for a larger version.
(1) First, unscrew every screw on the black housing in front of the OTA. There are 4 on the top and 3 at the bottom. The screws have to be unscrewed by Allen Wrench. I have 3 from Meade when I bought the scope.
(2) Afterthat, you have to remove the screws on the ring which have the specification of the telescope. Please make sure that you don’t point your scope down at this moment just in case the corrector plate fall down and result in severe damage.
(3) Caution! Although you have all the screws undone, don’t remove the corrector plate now or you will regret for life.
(4) Now, check whether the Meade engineer made a marking over the edge of the corrector plate and the black housing. If he did, continue to the next step. If not, you have to do your own marking. Make sure that it’s visible!
(5) Do you see 6 pieces of cork slices filled in the gap between the corrector plate and the housing? I suggest removing them before you proceed to remove the corrector plate. After removing them, hold your hand on the secondary mirror (the center obstruction) and turn the scope down. If the corrector plate doesn’t fall down at this moment, try the way below.
(6) You suppose to see 2 big gaps, don’t you? I used a knife which was small enough to fit into the gap and insert it to the maximum (the knife holder may touch the corrector plate now). Use the way that you open a tin with a spoon to remove the corrector plate. I heard a loud “boom” when I successfully remove it. Do you still have the secondary mirror mounted on the corrector plate? You better have it untouched because once it’s removed, you can’t put it back precisely. You have to call UPS and pickup the item back to Meade. Haha… Frankly speaking, I did remove it accidentally. Luckily, I made a marking on the screws that hold the secondary mirror. Luck really plays an important role. I was able to put it back almost the same as before.
(7) Okay, the corrector plate is removed. What shall I do next? I did cleaning of the corrector plate and removing of a toothpick which was ACCIDENTALLY dropped into the OTA via the baffle tube.
(8) Let me show you the back of the corrector plate which faces the primary mirror.
(9) No more, I am going to put the corrector plate back now. I restore the cork slices first. Wish you a happy removing! 
The camera on Mars Reconnaissance Orbiter (MRO) captured its first light of Mars in the mapping orbit, thus the high resolution image is obtained.
The image is acquired by High Resolution Imaging Science Experiment (HiRISE) acquired at 8:16 PM. The image scale is 29.7 centimeters per pixel. At this moment, the spacecraft was at the altitude of 280 kilometers. To be more accurate, at this resolution, a people is visible in the image.
Tomorrow, I am going to share some plugins to enchance your Adobe Photoshop CS2 in astromical usage.
My friend March05 has contributed very much this time. He has done the lunar eclipse sequence photo. Credits to him! The photo above was taken by his lovely Casio EX-Z750.
What about mine? I still have to adjust some of their brightness and crop them out. It’s quite time consuming.
Oh yeah! I just received my copy of Sky & Telescope magazine directly shipped from US this morning! This is my first magazine subscribed from US as well as my first Astronomy magazine. Not to mention that the contents are really good; however, the advertisements are just too many that I can see them most of the time. Nevertheless, they are quite informative as I know more about the astronomical instruments after reading them. Credits to all the editors!
Don’t you feel that this photo is nice? I used my home garden as the background in this photo. I like it so much!
This articles is supposed to be posted yesterday night but when I online today, I just found that this is still in the drafts. There must be something happened to my internet connection. Anyway, it’s here now.
Continuing the Pros and Cons of DSLR Astrophotography, Pros and Cons of CCD Imager is here. The chip of the DSLR is not as great as the specially designed CCD imager’s chip. Let’s look at its speciality!
Cooling system
Operating the imager under low temperature allows you to easily capture a library of fixed-temperature dark frames always needed in serious astrophotography.
Left: SBIG’s STL11000M
Noise is also significantly reduced becaused of the low temperature. There is a form of cooling called TEP (Thermo-Electric Power) fixing the temperature at a certain degree kevin. This is the best cooling system ever used.
Convenient
All of the imagers are controlled by a computer. You don’t have to click on the shutter or press on the bulb cable. As far as I know, every imagers are compatible on all of the commercial telescopes. Whenever you get a new scope, you don’t have to get an adapter.
Cost-saving
You could get a built-in autoguider imager to save the cost to buy a guide scope and a autoguider or another autoguiding capable imager. However, some of the autoguiding capable imagers are more expensive than the combo of guide scope and autoguider.
Antiblooming
Antiblooming is a must-have for long exposure imaging or the stars in the view will have long tails. Blooming is caused by the overwhelming photos in a pixel. Nevertheless, non antiblooming CCD has higher sentivity which shortens the exposure.
Others
Smaller chip is able to focus faster and transfer the data faster to the computer. B&W (Black & White/Monochrome) chip allows LRGB (Luminance, Red, Green and Blue) imaging by using a wheel of filters set and etc. B&W chip is always more sensitive than colour chip. Therefore, the photo by combining LRGB images into colour is more cheerful than one shot colour chip. A monochorme chip with a certain colour filter is more sensitive to that certain colour. It comes in handy to stress on certain features.
Cons
I would say that the only con of CCD imager is a large CCD chip is very expensive. Let’s say the SBIG’s STL11000XM Monochorme CCD imager. It costs USD10,000! It is possible to take a large image with a small imager by doing mosaic. It saves money but it takes time.
I’m sure that some of your know what does DSLR stands for. It’s Digital Single Lens Reflex. Let’s straight into the topic this time.
Dual Use
As you see from the left image, DSLR is just like a conventional camera. Therefore, it’s able to take both your family’s photos and astrophotographs. It’s more valuable!
Larger Chip Larger FOV
What does you get this time? This is maybe the greatest advantage over CCD imager. It has larger chip, thus it typically has more pixels in the chip. What can you do with this? You may print a poster! If you want to get the CCD imager which is as large as the CCD of DSLR, you need USD3k-6k. Let’s take SBIG’s ST-2000XM as an example, it costs USD2695 during the offer period! If you are concerned about the pixels, it does only have nearly 2 mega pixels but Canon EOS20Da has 8.2 mega pixels. However, don’t judge it just by the pixels. Everything has its advantages and disadvantages. (I suddenly remembered that we can print larger photos just by doing mosaic. This will be explained in Sunday)
Cheaper in the same chip size range
Just by comparing the Canon EOS20Da and ST-2000XM, you will know why I say so. Sure, it doesn’t mean that ST-2000XM is not a good buy.
Convenient
DSLR can be operated with batteries and the man’s hand. It does not need a laptop to control it. It does also take all colours in one step (this can be a disadvantage though, you may refer to The Best Imager: Monochrome CCD to know the pros of monochrome CCD).
However, DSLR usually producees more noises. It has to be modified in order to be cooled using the devices like the astrophotographers usually use. If the DSLR is not specially designed for astronomical use, it cuts the lights which is considered important by astronomer but unwanted by the public.
This Sunday, I am going to write about the CCD imager. Stay tuned! 
This farthest galaxy cluster observed from Earth is discovered by astronomers from the U.S., Europe and Chile.
Almost 10 billion light-years from Earth, cluster XMM-XCS 2215-1734 contains hundreds of galaxies surrounded by hot X-ray-emitting gas. The existence of the cluster so early in the history of the universe challenges ideas about how galaxies formed, said lead author Adam Stanford, a research scientist at UC Davis and the Lawrence Livermore National Laboratory.
A student at Carnegie Mellon University determined the mass of this galaxy is 500 trillion times the mass of the Sun by using the temperature of the emitting gas. Most of the mass is “dark matter,” a mysterious, invisible form of matter that dominates the mass of all galaxies in the universe.
The European X-ray Multi Mirror (XMM) Newton satellite is used by the XMM Cluster Survey (XCS) team to discover the cluster and then determined its distance from Earth using the 10-meter W.M. Keck telescope in Hawaii. The team is working on a long-term observing program to find hundreds more such clusters using telescopes around the world.
