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..

日本MIZAR望远镜最近也搬来深圳用,没为了别的,就为了找找星,喜欢找星。说起来我为什么会那么喜欢找星,这个也不太知道。可能和读中学一年级自然科学时第一次在实验室接触显微镜有关吧,香港初中一年级就开始有进入实验室,当时我有一段时间下课便走到图书馆里看一些这方面的书,微观生物的世界令我印象深刻。而现在利用望远镜,恰恰相反看的是宏观世界,遥远广阔的宁宙,目镜里看似平凡的东西,欲又不平凡。本是两回事,却又是同一回事,就是在那里找自已想找的东西。。。

把其中一部望远镜搬来深圳早在去年年中就有这个打算了,一直没真的去做,现在终於搬过来了,因为有时候我一家大小也在这边的。我会在阳台看,阳台能看东和南方的天空,或且有时会上楼顶看,楼顶的北极星幸好未被山挡住,我就住在顶层。

深圳是个年轻活泼的城市,年轻人多,我住的这个房子今年也有十一个年头了,深圳这个地方有著许多许多我的回亿 ,曾经走过的街角,有美好的回亿,也有伤感的回亿。我爱香港,也喜欢深圳。回想起,当年真没想到许多年後的今天,竟然会在这个土地上看起星来了。。。



MANDII
11年五一假期

看到你有一面面山
那是不是比較沒有光害?

下面是引用 笑笑 於 2011-05-05 09:32 發表的 :
看到你有一面面山
那是不是比較沒有光害?

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。  

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

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/ 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 .

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 .

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 ！

M27 在都市裡應該不容易看到..