ZWO Seestar S50 拍冥王星 

Capturing Pluto with the ZWO Seestar S50

又是趁阴雨天时处理一下日前拍摄的影像, 原来在海洋公园光影汇演时也能轻鬆拍下冥王星。这辈子只拍过2次冥王星，上次是用自己西藏遥控天文台的Officina Stellare RiFast 500口径卡反拍，这次郄是口径小10倍，只有5公分的Seestar，还要在香港这种Bortle 9天空拍，感觉既兴奋又复杂。

照片一 : 2023年9月25日摄于星河科研社新界西活动基地，当晚冥王星离农历十二的大月亮外才10度距离。

照片二 : 2023年9月月29日中秋节摄于海洋公园晚上光影汇演期间，当晚透明度很低，肉眼目视星等才2等多点，但同样是累计曝光5分钟，最暗但能清晰拍下到15.5等星左右。

以Seestar的相机每像素取样度2.4角秒，最少要三四小时才能检测到冥王星在天空的移动，但隔一天比较合理。现在两张照片隔开4天，移动就很明显了。我们后面的每月观星实习可以试拍这个 https://eshop.astro.hk/hk/catalogs/lists?sfor=default&sfna=%E8%A7%80%E6%98%9F%E5%AF%A6%E7%BF%92

Once again, taking advantage of rainy days to process the images taken earlier, I realized that I could easily capture Pluto during the Ocean Park Multimedia Shows. In my lifetime, I have only imaged Pluto twice. The previous time, I used my own remote-controlled astronomical observatory in Tibet with the Officina Stellare RiFast 500 Reflector. This time, the aperture is 10 times smaller, with only a 50mm Seestar. Moreover, I had to capture it in the Bortle 9 sky of Hong Kong, which added an excitement yet mixed feeling.

Photo 1: Taken on September 25, 2023, at the Galaxy Scientific Group activity base in New Territories West. On that night, Pluto was just 10 degrees away from the near full moon.

Photo 2: Taken on September 29, 2023, during the Mid-Autumn Festival at Ocean Park's Multimedia Shows. The transparency was very low that night, with a naked-eye visual magnitude of only around 2th. However, with a accumulated exposure of 5 minutes, I was able to clearly capture stars as faint as magnitude 15.5th. 

With the Seestar camera's pixel sampling of 2.4 arcseconds, it would take at least three to four hours to detect Pluto's movement in the sky, but it is more reasonable to observe the change over a day. The two photos were taken four days apart, and the movement is quite noticeable. We can try capturing this during our monthly stargazing workshop in the future https://eshop.astro.hk/en/catalogs/lists?sfor=default&sfna=stargazing%20workshop