天文观察摄影雜记---林月笙香港天文台

台湾

笑笑: 2011-05-03 09:06
原來啊
香港最熱的是 7-8月
很不巧的是我幾次去香港都是這個時候
難怪熱的受不了.. 表情


笑笑:2011-05-05 09:32
看到你有一面面山
那是不是比較沒有光害?


MANDII : 2011-05-06 10:15
是的,西北到东南半边天由山包围,说起来这跟我香港住的地方一样，也是西北到东南一半是山。第三张照片望远镜就是指向正北北极星的位置,第二张是正东。有一半天晚上很黑的，前几个月有一个晚上最暗5等星肉眼看过。西半天就是闹市，房子就很多，不过都不怎么高，一般都在视线以下。天空会光点比较东半天来说，但肉眼也能看到3等多4等的。东边的山不高于30度，应该在20度左右，天球天顶位置（就是面向南70度左右的高空位置）在阳台不用站很外面的位置都能看到,因为楼顶比较高。因此阳台漂移对极这点问题不大，有需要拍摄日后可以考虑，目前以简单的目视为主，找星团为乐，星系恐怕镜子达不到要求。

帮顶

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谢谢
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US ASTRONOMY

Uncle Peter : Yesterday, 07:06 PM from Toronto, Ontario
That's a very nice addition to your observatory, Mandii! Do enjoy it!


MANDII : Today, 11:00 AM
Thanks Uncle Peter , I had nothing to say more , except Thank you .

US ASTRONOMY

BobDob : 05-31-2011, 10:40 PM from South/central Montana, US
Nice going, Mandii. You have an observatory to be proud of...

BobDob


AdamR91 : Yesterday, 12:13 AM from Barnhart, Missouri, USA
fantastic shots, keep them coming and keep them classy.


MANDII : Yesterday, 02:57 PM
Thank you BOB , I will keep on my astro-observation .
And thanks AdamR91 as well .

CLOUDY NIGHTS

LoveChina61 : 06/23/11 04:43 AM
Mandii,

Great shot of the Orion Belt! A little more to the right and the Orion Nebula would have come into view as well.

I really enjoyed my visit to your observatory late last year when I was in Hong Kong for my operation. I learned a lot from that injury. 50 year old guys should not get out there with the young guys and play American football. Ouch! That really hurt when my bicep completely separated from the elbow and balled up near my shoulder. Good thing that Australian doctor knew what he was doing when he pieced Humpty Dumpty (me) back together again! he he

I still lean heavily on my LX200's Go-To system to find my way around the heavens, but I was quite impressed with how you made computer printouts of every target and then methodically planned how you would hop from star-to-star to find the final object you were looking for. It was wonderful to spend time with another "brother" who loves astronomy just as much (or even more!) than I myself do

Clear skies! Mike





MANDII : 06/23/11 04:50 AM

Thanks Mike , ha! ha!
Just a moment ago , I see you also had a thread in this forunm . I see your name .

Take care yourself .
Someday when you come HK again , don't forget to call me , we can have a tea time together on a same table , same as last time . Ha! Ha!
And I totally supporting you in building a observatory in USA , that's a good place to have an observatory indeed !


Wishes you good health ,
MANDII
2011/06/23

台湾


Jeff: 2011-07-13 11:34:36
基座凸出建議裁短~~雙螺栓加雙螺帽

堅固與安全性增加



MANDII : 2011-07-13 15:29:05
谢谢Jeff 兄的一些意见。 Smiley
基坐目前是倆块30公分X30公分尺寸的铁盘,厚0.8公分每块，原意搞大点柱子就比较站得稳，而且特意要做成正方型，因为镜子摆动时上面整个器材的重心不在柱子正中间的，而且日后也有可能会使用更重的赤道仪和望远镜，因此当初不放心就4根爆炸罗丝固定地板会不够力，就告诉厂家搞大点底盘，一定要那么大的尺寸。那样一来，当时在电话里也无法想像到凸出的地方也是比较多，不过现在用了一段时间感觉还好也不怎么占地方，毕竟室内也有接近2米2直径的空间，而且一般观察时脚底是放在盘上面。另你看到的那4根1.5公分又大又长的罗丝每根都有上下倆个罗帽和介子钳住上层的那块底盘，大罗丝就焊死下层底盘,下层底盘就 4根爆炸罗丝固定到地板上,那样柱子才可以调节高度，也是正如你所说的用倆个罗帽比较坚固。

CLOUDY NIGHTS / US ASTRONOMY


The maunal Goto methodology using object's TIME-ANGLE to find a deep sky object and take a picture of it .

Objective :
- It'a a fixed point observation ( visual and photography in a observatory )
With a low costing mount (EQ3) that do not have the GOTO function ,
- Manually search the deep sky objects in telescope , by using the object's time-angle at the time of observation ,
and turns the RA and DEC circle from the mount , to find out the objects in an eyepiece ,
- And take a picture of the object , note it down in a observation report .



Night Sky condition : In bewteen Urban and village place , not so many clear nights (without the clouds ) in a year , visual magnitude around 4.0-5.0 in clear nights .

Equipment cost : Telescope : Orion 6"/F5 Newtonian ( 2nd hand at price 1500HKD) that comes with several eyepices
Mount : EQ3 with one RA motor .( 2nd hand at price 300 HKD)
The height adjustable Pier ( self made at price 350 HKD)
Camera : DSI-I ( 2nd hand at price 800 HKD)

Total : 2950 HKD


Observing time : most of the time the obeservation taken place from 9:00p.m - 12:00p.m 3 hours of time ,
Within 3 hours time ,need to complete the whole observation in finding the objects and taking down it's image .



Steps :

0. The mount( EQ3) is Polar aligned well . This can be setup One time in ordinary day instead of observing night .
The alignment accuracy and requirement should be reached to the level that , the stars roundness under 2 min exposure in a single frame image , is accepted by your own . The better the mount is aligned , the better( more round ) the stars in a picture , and the more accuracy in finding out the objects by using it's time-angle value . In my case , I had to use drifting method since the polar star cannot be seen inside the obervatory polar scope .



1. At observing night , initialize the mount's RA calibration such that it can synchronise the stars moving position . Meanning that when you rotate the mount's RA axis to a certain value of a Time angle , the telescope should be pointed to the object that is located at the same time angle . Stars or DSO moving from east to west starting at time angle RA 18h00m00s up to 6h00m00s . 18 hour at eastern ground , 19 hour ...24 hour( at the top of the sky ) , 1 hour ,2 hour and so on ... upto 6 hour it reach the western ground . So totally 12 hours of time it moves the whole night sky . The DEC value of the object should be always fixed in reagrdness to differnt observing time . And the object can be seen in a eyepiece directly under the FOV of around 2 degree in an eyepiece . The minumin unit of the mount in RA circle is 10min , DEC circle is 2 degree . Thus , the FOV in an eyepeice should be setup samly to the FOV of the minimun unit( 10min and 2 degree).


The initialize process is :
a. check the target DSO object is located at the eastern or western sky hemisphere at the time of observation .
This can be easily known from the star chat in a computer .

b. If the target object is located at the Eastern hemisphere , point the telescope to the East horizontal level( approximate is OK ) , and then turns the RA circle to value 18h00m00s . After that , find a bright star in eastern sky , and point the telescope to it such that it is located in centre of an eyepice , then check it's time angle( e.g 21h10m00s) from the star chat at that moment of time . And turns the RA circle to it's time angle(21h10m00s) accordingly . After this step ,the bright star should be setup it's time angle in a mount . The RA axis becomes life . It looks like a real clock of the star moving time . Let say after 1 hour of time , even the motor of the mount is not switched on , even the star moves to a certain position of a new time angle , you just check the new time angle of the bright star from the star chat , and you can turns to the new value of RA circle to point directly to this bright star . The DEC value is just fixed no matter the star moves . Such DEC value of a star can also be known from the star chat . So we can point directly to a star by turning these two value of RA( time angle) and DEC of a star . The westren hemisphere initialization is same , but just at first point the telescope to the westren horizontal level first . And set a bright star at western side instead of eastern side . The other procedures are just same .





2. After the mount is initialized as a real clock of actual stars .
We can use the mount to find any of the objects now .
Each object should have a time angle and DEC value at the time of observing .
The bright stars do have , the DSO also have this two values .
Even the planets , and the moon is also have this two values .
Let say in more simpily , I just turn the time angle and DEC value of the mount , after that the moon can be seen in a eyepeice directly . I don't need to find it manually in a telescope . Samely , the Jupiter , the Mars and the DSO is found in same way .
These two values of time angle and DEC , can be known from the star chat in a computer , for any of astronomical objects .
What we need to do first , is just to initialize the mount to a real CLOCK of star moving .





3. After the object is seen in an eyepiece , I just insert the DSI to the eyepice holder , and starts the imaging process .
Most of the time I use less than 2 min of single frame exposure . And takes around 10 to 20 frames to do stacking and post imaging process . Finally , the DSO picture is got .


THE ABOVE IS SO CALLED " MANUAL GOTO/MANUALLY FIND A STAR BY USING IT"S TIME ANGLE "



I attach several picture samples that was taken by me in past times , using this manual star searching method .



MANDII
2011/07/22

CLOUDY NIGHTS


LoveChina61 : 07/22/11 06:50 AM from USA
Great job of taking some nice pictures with reasonably priced equipment! Keep up the good work. You are an encouragement to us all



Starman27 : 07/22/11 11:14 AM from Illinois, Iowa

Good images. Great classic approach.

Cloudy Nights/ US ASTRONOMY  

I need to revise some of the point in the above .
Firstly , In case it's used in western hemisphere , the RA circle is initially set to 6 hour compared to the 18 hour Eastern case . And also, this kind of initial setup to synchronise the time of the moving star , is a one time setup that can be used throughout the continuous several nights . No need to do the same setup evry night . Because stars position at same timming in two continues night , is bascily same under the FOV of the telescope in 2 degree .  

2ndly , The stars and DSO is fixed the DEC value all the time . The Moon and planets changes this DEC value as the observing time varies . Basicly this mimute and next minute , is differently and obviously seen under a big magnification in the telescope .
Visual position( time angle and DEC ) always changes with time tremendously ,under magnification .   
The Sun may also changes DEC value . I am not sure about the Sun as I haven't observed it previously .
However , even they change DEC , it can be easily got this value from the star chat , in any of the observing time .  

If you turns the mount's two axis( Time angle and DEC ) , to point the telescope to the SUN and take a picture of it in camera .
Such approch do not need to use your naked eye to find a SUN in a telescope , and even throughout the whole imaging procedure .
Meaning that : Avoid the risk of our naked eye to be hurted by the SUN , by using this a cheap and practical way of so called "Human  GOTO" methodology .

US ASTRONOMY


Tarantr : Yesterday, 11:23 AM from Melbourne Australia
Hi Mandii,

Thats a great observatory setup,

Well Done!


MANDII :
Thanks Robert .
Do hope you clear skies .




CLOUDY NIGHTS

UmaDog : 07/25/11 07:23 PM from Long Island, NY

Thanks. Ever get that shot of M93?




MANDII : 07/25/11 09:59 PM
Thanks you remind me this M93 . Yes I have to agree , it's nearly a 5 months time I haven't got even ONE picture of the deep sky ,since last time I did say to get the M93 on end of Feburury . Frankly speaking , it's very difficult to get a picture of DSO . For me , the main challenge is not any other thing , main difficulty is to keep on myself not to become a lazy man throughout the long waiting time of a clear nights . In Hong Kong , basicly every night is cloudy nights . You are getting disappointed during the waiting time . And you are not sure which day a clear night suddenly come . And you have to move your body right away without hesitation ,when such a clear night comes . And that is the real diffculty for me to move my body once again while I have been waiting too long .


But I will keep on doing it , too much excuse is no use , I will keep on to take as much deep sky picture as I can , by using the current equipment in my comming years of time . I insist to say without too much changes starting from the very beginning( 1 or 2 years ago) in using my equipments , the telescope , the mount and the camera ,though they are a very cheap equipments , but I believe they are just situable in my actual situation . They are the real good tools that can help me take Deep sky pictures .

I believe the time can solve this kind of difficluty as well .

US ASTRONOMY


BobDob : Today, 03:52 AM from South/central Montana, US

Mandii, I sympathise with your situation. My advice is as much for me as it is for you: Perservere. We do what we can with what we have.

I encourage you to look into what can be done with video cameras. In light polluted areas amazing views and pic's are possible. Yes, good tracking is important, but you get what you can with what you have. Stacking shorter images is better than no images or views at all.

I'm looking forward to what you will share with us.

Be well, under Clear Skies!

Your friend,

Bob





MANDII : Today, 04:44 AM
Yes BOB . You are going at the front I am sure , for long decade of time , especially in this new field of video cam.
Video camera of macllinicam should be in serious consideration when I start to think about the changes in future . The changes of my equipment mostly I will focus on camera . A good camera with great sensitivity ,and fast capturing speed , is always the best weapon in tackling with the Deep sky under my local sky condition . You had said very well that stacking a bit is better than stacking nothing when the mount's tracking performance is not really good . In my case , 1 or 2 minutes of tracking in single frame under 750mm or 600mm focal length , is still feasible and still works on my mount when it's motor goes . Thus , I can imagine that this 1 or 2 minutes of time , should have a great use for such video device .

But there is still a quite long way to go , before it's changed .

US ASTRONOMY

Uncle Peter : Yesterday, 09:31 PM from Toronto, Ontario, Canada

MANDII, I wish I could give you my clear skies!

I sold my other scopes a few weeks back, and got a 6" SCT that is almost here. Ever since I sold them, the skies have been super clear. I'm imagining already how cloudy the skies are going to be when the scope arrives though.

Looking forward to those awesome photos and clear skies,




BobDob : Yesterday, 10:16 PM from South/central Montana, US

MANDII, if the DSLR is your preference, go for it. I only suggest the vidcam as a much less costly route to get not only good live views, but very respectable stackable images, especially in light polluted areas.

You are getting pretty good tracking from your equipment. I assumed you were getting much less. To my understanding, one to two minutes is ample for a vidcam. May I suggest you consider a Samsung or others of the cams which are being used? I don't know what cams may be coming from Chinese manufacturers. I do know there are a number of cams being used, which are much less expensive than the MC (the best, but very pricey), and with pretty good results.

You are familiar with Night Skies Network Quite a few broadcasters are using cams far, far less expensive than the Mallincam. One fellow in particular, Ken James, an Aussie down in Snake Valley, has some great results with a Phillips ToUcam. I'll find his website for you. Here: Free website built by Ballaratman using My Personal Portfolio . Click on the "Videos" tab for an idea of what is possible.

True, his conditions are very different from your's in Hong Kong, but with a LPI filter you will get stunning results, far better than you might guess. I recommend you contact Ken and introduce yourself. If he can't coach you he may be able to recommend someone who can suggest what you should try in the way of gear.

Perservere, my friend!





MANDII : Today, 09:41 AM

Well uncle Peter , You had did so many DSO observation previously and have well noted all of the objects in report . That's no easy . Actually ... I knew that it needs great skill to find the objects by star hopping method as you did , and probably most importantly the experience in knowing and getting used with those night sky constellations and those importatant reference stars , etc ...

In some of the past days , I had also tried this star-hopping throughout the way in finding the target but most of the time I failed to do so , anyway I was not able and do not have much experience to find the target object by using this method . Thus , I finally decided to change to use the numeric calibration or the scales circle on the mount EQ3 . In such case I can directly point the telescope to the object by numeric coordinates , even I don't familar with the constellations and stars in the night sky . That way is simplier for me . However , it's always true to say that the star-hopping method is a skillful and classic way in finding the objects out .

I know you are planning to do imaging . So probably it's a good time right now to take a rest , or you will be getting very busy latter on in imaging , Ha Ha .



MANDII : Today, 09:42 AM
Again , really thanks BOB for this important information on the cheaper video cam . I will study more on your links above , Thank you !


BobDob : Today, 10:35 AM from South/central Montana, US
You just keep doing what you've been doing all along, Bud'. A lot of us out here are admiring what you have accomplished.

Clear Skies!

Bob

好帖一个，LZ是比较专业一些的同好

作晚上楼拍M27,没拍成,连找也找不到。。。现在也没多少劲写过中经过。
这篇天文杂记，有拍到有照片的固然是好，要正规地记下档案，现在觉得没拍到失败的也得记下，好让日后回头看，不写下来还是没倆天就忘了。上星期5晚做了漂移，首次有机会正式把新装的铁柱对好极轴，算是凑合对好吧，再碰到作晚好天，也有闲情看星，便兴致勃勃的想看看M27，拍个M27来记档也好的。劳累了一整晚三个多小时到11点多钟，结果还是吃白果。有点失望，有5个月没用望远镜看深空了，技术变得很生疏，连找都找不到。。。找得到之后的步骤一彻都好办，找不到真的没啥办法。

感觉越来越难了 ！

台湾

aa: 2011-07-28 14:58
M27 在都市裡應該不容易看到.. 表情


MANDII : 2011-07-28 17:07

喔是AA你来了。我以为它跟M57差不多暗的，样子也差不了多少，去年也同样的在7月份用15秒的DSI，照片上隐约能看到所以作晚就很想试下M27。
其实你问的这个看不看得到的问题，其实是一个很复杂的问题，也是一个一直以来我所关心的核心问题。不是那么简单回答是能看到,还是不能看到便可以的。要怎样来确定是看到还是看不到的一个问题。

我的分析是这样的：
以作晚情况来说麻，当时10点钟左右M27在东边约5，60度的高位，我就人肉时角GOTO把望远镜一指就指过去,指过去以后呢就希望能在那个小范围内（估计2度赤纬和10分钟赤经之间的误差内）再进行星点比对以更进一步确定它的位置，以最终要眼看到它为止。我用K25mm目镜就大概1度视场。去年的 M57 我就能目镜里看到。如果看不到而能确定它的位置也行，那样我依然可以拍它，照片上可能就能看到了。左手拿打印出来的星图和小红光电筒，靠近目镜看，右手细调赤道仪控杆，单眼边看星图边看目镜里的星点。别说在这个小范围内的星点也是蛮多的，高至8，9等的星都有都看到。只要能确定它的位置，便能知道你的问题的答案：就是到底是看得到，还是看不到，还是拍不到等等问题。

那到底问题是在那呢 ？问题是我无法确定它的位置在星点比对的过程中，这难关也是向来我都不怎么能搞得定的难关。K25mm目镜里大概是1度视场，我检查过赤道仪对极后的纬度偏差是2度，这只要看一粒亮星便知道偏差多少了。赤道仪上的刻度我只用到整数位，比如目标纬度本来是24.7度，我就调到24度可以了。赤道仪最少单位是一格2度和10分钟，那再加上对极偏差2度，总共偏差可能在4，5度左右吧。而我的目镜是1度。所以麻，虽说已经走到小范围内了，但这25倍目镜视场的范围，还是蛮大的一个范围，而M27就应该是在这个范围内，我就要在当中确定M27的位置所在，这是一方面问题。

第二个更大的问题是关系到牛反影像倾斜的问题 ，它是没有固定的，望远镜不同指向时倾斜度都不一样，那我怎么知道当时目镜里的星点是应该怎样来看是不是？比如如果我是知道它当时应该是倾斜45度的,那么我就可以把星图旋转45度来看，又比如像折射镜那样无论是那个指向它都是上下颠倒，那我就倒过来看星图是不是？只要我看到目镜里某几个星，它们对得上星图上的，比如它们组成的形状，是四边形，三角形或多边形什么的，只要能对得上，那我就很清楚目前所在位置，那就很容易上下左右移到目标位置那里了是不是。可问题就在于我看不出来，对不出来，我不知道我那张星图纸该要怎么个方向来看才行，而且牛反来说每次都不一样，因为它的影像会随指向旋转。 这便是另一最大最大的问题。

所以麻，我可能还会再试下。。。

US ASTRONOMY

Uncle Peter : Today, 08:02 AM from Toronto, Ontario, Canada

I'm actually glad I didn't buy a GoTo scope when I first started out with Astronomy. You are right, it does teach you very important and essential skills that will help you succeed in Astronomy.

It was hard at first to star-hop, but as with anything, practice makes it easier and easier. I also find that star-hopping is a lot more exciting than using a GoTo scope. It makes you feel like you are on an adventure, or something like that, to try and find a DSO or a star.

Just because I'm getting a Goto scope, this doesn't mean I will stop star-hopping. From what I know about Goto scopes, they have a manual format where you can move the scope with the controller.

Imaging will start shortly after I get my scope, Mandii. I plan to buy a CCD camera this month, and maybe an Orion autoguider and an off-axis guider later on.

Clear skies,






MANDII : Today, 10:08 AM

YES ! Surely agreed to what you said here .
Very well said indeed !

Cloudy NIGHTS


MANDII : 07/29/11 11:46 PM

Thanks Joyce , I guess you are a chinese girl . May be you come from Hong Kong as I do ?? Cause I know that normally chinese people is not being able to connect to this Cloudy Night forunm . Anyway Thank you very much for your kind touch on this thread !

US ASTRONOMY



MANDII ：
ha ha ! BOB you are right . I also thinking about my financial ability to own this mallincam , I will study more those cheaper videocam as you mentioned above , anyway really thanks you a lot for this importatnt information !

BobDob ：
MANDII, I don't know if you are a spriritual person. I happen to be one. I follow the direction I feel from within. In your case, I have felt led and directed to support and encourage you. This is where I am coming from. This is a full disclosure.

I have watched you perservere with limited means to achieve great accomplishment. You have created an observatory of substance in a difficult enviornment. You have communicated with your peers in a very foreign culture and language, and they have shown you respect and offered you fellowship. You have accomplished a great feat, in my eyes. I could have not have do so. I admire you.

My brother, I only want to thank you for being you.

Your brother and friend,

Bob



MANDII ：
wow BOB don't say this ... I just have little achievement as of now .
It's my pleasure indeed to come to this place in an occasional way back to two years ago . I am just a person who enjoy the night sky . And I want to do somthing on this area . In my eye , you are really a great person , who have did a BIG project and BIG observatory in a HIGH mountain !! The point is the harzard place in a high mountain ! The monata mountain in US !! WELL , that's really not easy for an ordinary person . And much more difficult even for an old man like you to do this kind of TOUGH JOB !! NOT EASY ! Though I am not sure finally how finally your observatory goes on , But that's not important . Final result is not a matter . The point is you have tried it ! So I really admire you on a such attempt to build an observatory in high mountain . BRAVE MAN !


BobDob：
My dear brother, let me clear up a misconception. Your admiration of me is misplaced. I began my observatory on a misconception. This is a long story, so please forgive and bear with me.

When I came to Montana, it was to build an observatory for a client. The hope for both of us was I would like this area, which I did very much, and I would like to stay here. I did love this region and wanted to retire here. He was to provide the materials and I would provide the labor and expertise, and we would build an observatory for us to share.

Well, my years (69 this August) betrayed me when I had to begin working nights in security at the local precious metals mine. So, I had to admit I could not honor my part of the agreement, and we parted ways.

In the process of this, I realized he had taken my wheelbarrow and used it for his own needs. Naturally I resented this, but said nothing. My great error was I held him in judgement for his behavior.

And, I relocated and began my own observatory. It was very hard for me. My age betrayed me and I found each day of labor nearly more than I could bear. How I regretted the passing of my youth. I pressed on.

One day, I had an insight. For the two years since I had left my friend's project, I had resented what he had done. But, I had not once needed a wheelbarrow. There were two at the ranch where I was living and building my observatory, but I had never used or needed either one.

Then, came the realization that I was holding my former friend guilty for an offense which made no sense. And, it had made the building of my observatory far harder than could be justified.

So, I emailed him and told him I had forgiven him and the wheelbarrow was his. I gave it freely to him.

He emailed me back and asked me, "What wheelbarrow?"

Then came the understanding that he had thought the wheelbarrow had been dropped off at his place by a friend who had told him he would do this. You see, he did not know the wheelbarrow was mine.

And, all this time I had thought he had done a very mean thing to me. He had no idea of this. So, we have cleared all of this up, and are the best of friends. And, we are sharing the observatory which we started to be for the both of us.

So, my observatory? It is nearly finished, but is no longer of interest to me. I have a friend who is sharing his observatory which we began to be for both of us. And, we are sharing it in fellowship and good will, and enjoying this very much.

The moral? As in many religions and philosophies: judge not, forgive all, and love everyone without condition. Lao Tsu, Jesus, Buddha and many others have made this plain. Unfortunately, even though I knew this, I managed to overlook it in this case. So, I am embarrassed but wiser for the lesson I thought I had already learned.

Life has a way of giving us tests to see if we have really learned its lessons.

Be well, and be wise...Bob



MANDII ：
Understand BOB . Anyway , take it easy .
You are always Number ONE in my point of view !



BobDob ：
Thanks, MANDII, I have the highest respect and regard for you, too!

Bob

NO.26)

今晚拍到M2 . 天空没什么云,没有很清,肉眼能看到约5个星座的主星.

ORION 6"/F5 Newtonian
EQ3 unguide
DSI-I ( 30s X 17)
IRIS

Observe : 2011/08/01 10:45p.m