天文观察摄影雜记---林月笙香港天文台

[MANDII]

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

[MANDII]

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

[MANDII]

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 .

[MANDII]

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 .

[MANDII]

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 ！

[MANDII]

台湾

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。。。

[MANDII]

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 !

[MANDII]

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

[MANDII]

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

[MANDII]

NO.27 )

Tonight M15 , little cloud , but transparancy worser than previous observing night .
I can't see the comic near M15 in eyepiece (K25mm) , though I had searched it for long time around the region of M15 . The DSI even much more smaller picture-FOV ( at least 4 times smaller ) than the eyepiece , thus it surely cannot cover this comic in picture . Anyway , this is the result of observing , tonight .


ORION 6"/F5 Newtonian
EQ3 unguide
DSI-I ( 30s X 16)
IRIS

Observe : 2011/08/03 10:00p.m

[MANDII]

CLOUDY NIGHTS

UmaDog : 08/03/11 10:59 PM from Long Island, NY

Thanks for posting! I like M15. I spent some time trying to see the planetary in it on Saturday. I think I found the location but couldn't confirm it.

Do you ever get the chance to make trips to darker skies?




MANDII : 08/03/11 11:50 PM

well sir bascily I am a lazy man . I am lazy going out and no such time as well after work everyday .
I don't want to bring things . It's probably not the reason of distance , let say even I just need to setup the telescope every time observation on my home platform , just on my platform , and evreytime bring back these equipments after complete the observation . " That would also be a diffculty for me " . So you can understand now how it is impossible for me to go out . And that's the main reason I setup an observatory . Also , I want frequent observation , not talking about seldom use my teslecope , so frequent that I observe so many things like the Moon ,the planets and even the Plants on the nearby hill as well . Not only the DSO . So how can I setup the telescope every time if it's needed so frequently ?? That's impossible without an observatory that already setup and keep everything
well for you in a outside place .

2ndly , my location is quite dark already in Hong Kong , though it's not very dark but still OK . If the outside dark area is clear that night , then my place is just same . For me , The main problem is not the darkness in my site , it's the weather of cloudy nights and the quality of sky . I mean the Dust and thin misky layers that always covers the whole sky and make the tarnsparancy very low . And this is geographic weather matter , basicly everywhere in Hong Kong is just same . Not so many nights in a year without the clouds , not so many nights has very sharp stars . No matter where you go in a such small place in Hong Kong , the sky is just same . Cloudy and unclear nights . That's why I come this cloudy night forunm now .

[MANDII]

<< 天文观察报告和照片综合列表 >>

总引：
深空天体观察中，人手寻星是最令人兴奋，最有成功感的一个过程。观察记录便有必要把这方面具体地体验出来。寻星用的星图见其效用，于观察当晚打印出来用。
人手寻星图列表，见“予定的天体目标”数据库。 http://www.hkastroforum.net/viewtopic.php?t=17905&start=45

记录条: 天体名称 日期1_照片顺序号 | ... |日期N_照片顺序号
观察报告图内容:
包含予先造好的寻星用星图,和当晚拍下的实体照片，合并为一份观察图，也能查看予定和实际观察上的时间延迟,方便日后跟进以及管理。

M2 : 2011/08/01_NO.26
M13: 2010/6/29_NO.9
M15:2011/08/03_NO.27
M31:2010/12/26_NO.19
M42 : 2009/12/05_No.1 | 2010/01/12_No.2 | 2010/01/31_No.3| 2010/12/08_No.15
M44 : 2011/01/31_NO.21
M50: 2011/02/05_NO.23
M57:2010/07/04_No.11
M64(天区):2010/07/01_No.10
M101(天区) : 2010/06/07_No.8
M103:2010/12/26_NO.18
NGC457:2010/12/26_NO.16
NGC663:2010/12/26_NO.17
NGC869/884:2010/12/31_NO.20
NGC3242: 2011/02/05_NO.22
NGC7000(天区) : 2009/11/21_No.4
火星: 2010/01/29_No.5
土星: 2010/03/19_No.6 | 2011/02/23_N0.24|2011/02/24_N0.25
Stars : 2010/01/20_No.7
Moon： 2009/12/23_No.0
木星: 2010/10/11_No.12 | 2010/10/12_No.13 |2010/10/13_NO.14|2011/09/27_NO.28




Total 21 objects 29 observations




MANDII
Created on 2010/05/09
Updated on 2011/09/28

[MANDII]

NO.28 )

木星: 2010/10/11_No.12 | 2010/10/12_No.13 |2010/10/13_NO.14|2011/09/27_NO.28


ORION 6"/F5 Newtonian
EQ3
2X Barlow
DSI-I ( 0.0387s X 735)
Meade Envisage Drizzle Box stacking , Registax .

Observe : 2011/09/27 11:15 p.m

[MANDII]

No.29)

补倆张M42和M45漏记照片。那时家里有部老爷机Olympus C-40 Digital camera  , 目镜（K25mm)后拍摄，暴光只能16秒，10张叠加。
这倆个M天体很亮，此DC机够感光，这倆张照片算是我比较满意的，当时给了我很大稀望，以为找到了现成的机子，可以不费一分钱又能达到个人拍M天体的目的。
想一直用它来拍，我是想拍比较亮的M天体，星团类为主，后来很失望在接下来倆三次中拍不到其它的星团，连M6，M7都不行。感光不够没它办法。
所以后来只能继续用DSI，DSI 是三年前决定用的，是我现有相机中感光最高的一部了，一直以来也没打算更新器材。

Orion 6"/F5 newtonian
K25mm eyepiece
EQ3
Olympus C-40Zoom (16s X10 )
IRIS , Photoshop

Observe :2011/12/27

[MANDII]

还有4张今年的要补上，当时因为懒得写中文报告就只记在外国论坛里，现在补贴后整篇贴就完整了。


NO.30)

Tonight very excited . The sky suddenly become a bit clear without not much clouds at around 10 o'clock . So I quickly take action . I spend around 30 minutes to find out this M41 by myself , I am very pleased when I see it . It's really beautiful in the eyepiece , so many bright stars ! And then after looking it for a while I turn to do imaging . At first I use my Omlympus Digital camera since last time it can have enough sensitivity on M45 and M42 , but this time M41 is much dimmer . It cannot be shown even a little bit of this M41 on the camera display at it's maximun 16 seconds exspoure . And then No way so I have to change to use DSI , so fianlly I can catch it at 15 seconds per frame in DSI , I take 22 frames . Finally do stacking in IRIS , and finalize in PS . Tonight the observing session is fine . The time now is 0:46am.