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Hi all,

Pls take a look to Gamma Virgo (bright star just next to Saturn) , it is a double with separation of 2 arc sec. now . It was resolved in my 106mm refractor at 265X .

Ben

Ben, thanks for sharing.

沒看過這個，我猜以100ED折射鏡來說應該很容易。

因為10年前我們搞學生活動，用一批114/900球面鏡的牛頓鏡及廉價Plossl，都能解分解Epsilon double double的，若用APO則四星完全分離。

http://en.wikipedia.org/wiki/Epsilon_Lyrae

但我有個心願還是想用203APO在香港看天狼B，那次在檳城用228APO很容易看到，但香港過去幾次我看時的視寧度都不配合，現在Paramount的三腳又賣了，203APO又要發到西藏去做深空，所以可能要一兩年後發回來香港才能再看。

Yes , I must be ok for a 4 inch telescope (2" separatiion) . However , I missed this object as I\it could not be resolved in 6 inch APO few years ago , accoring to CN - it would be quite interesting to see the changes of the double from a "snowman" to a clearly splitted double in few years .

However , I could not 100% confirm the Antares B in the 4 inch even using the ultra sharp mono 4 (sharper than LE 5 ) ... I could see it in my 10 inch newtonian couple of years ago.

Besides , Sirius B is also my target in the coming year . I failed this year

對，這是一個很有趣的現象，其實雙星也不是靜態的，就算我們唸書時跟現在比，北極星也走近了北天極很多呢。按理恆星是最高對比度的目標，大口徑反射鏡還是有優勢的，當然前題是光軸及視寧度許可。

Antares B.... 有機會拿台105來試試

用了8年Mono目鏡，總體感覺像80年代用f12長焦折射鏡配Or目鏡看行星月面的一樣高對比度，當你用80APO推上216倍，就算我在上水這種天空背景光，我仍是看不到光欄的，因為眩光壓得太低了。

對大部人來說，除非他的望遠鏡特別大口徑焦距超長，否則就是Mono 4, 5, 6已足夠，加起來就是一個Ethos 21多點。我個人不喜歡在目鏡上花太多時間(望遠鏡也是)。

benben88 寫:It was resolved in my 106mm refractor at 265X .

Great! I saw a discussion about this in Sky & Telescope a few months before but never remembered to look in that direction.

社長 寫:但香港過去幾次我看時的視寧度都不配合，現在Paramount的三腳又賣了，203APO又要發到西藏去做深空，所以可能要一兩年後發回來香港才能再看。

我讓C8給你用吧，很久沒有用這支鏡了，我用它看Sirius B的！

若我肯再用折反射的，從貨架上拿台Maksutov 180/2700便可以了....

What about 80mm APM? Theoretically, it is marginal... Anyway, I will try all 80APM, 120ED & M8 etc.

I can lend you my 203APO, but get yourself an equatorial mount.