長久以來，我們對於外太陽系都知之甚少。那是一個寒冷的世界，陽光十分微弱、天體的密度也很低。在這裡圍繞太陽公轉的天體是半人馬型小行星和海外天體。他們是太陽系最原始的天體，因此，他們也是探索太陽系形成與演化未解之謎的關鍵。

在我們的研究中，我們利用了Zwicky Transient Facility的最新觀測數據，對半人馬型小行星和海外天體的表面特性進行研究。研究包括他們的顏色分佈、表面變化以及彗星活動。在我們的長期觀測下，我們得到了32個天體的顏色數據，其中的5個是我們首次獲知它們的顏色。

對於半人馬型小行星(517717) 2015 KZ120，我們大量的觀測數據證明這是一個偏紅色、偏橢圓的天體，自轉週期為10.7633小時。通過檢查它的表面亮度和不同自轉角度下的顏色，我們並沒有找到其具有明顯的彗星活動或是表面顏色變化。此外，我們的動力學模擬還發現(517717) 2015 KZ120受到來自行星很強的引力影響，中位生存時間只有大約1200萬年。

For a long time, we knew very little about the outer solar system. There is a freezing world, sunlight is extremely weak and the density of object is very low. Orbiting in that region, Centaurs and Trans-Neptunian Objects are the most primitive objects in our solar system. Therefore, they are the key to
understanding the mysteries of the formation and evolution of the solar system.

In our study, we use the latest observational data from the Zwicky Transient Facility to investigate the surface properties of Centaurs and TNOs, which include their color distribution, surface variations and cometary activity. We have 32 Centaurs and TNOs object color data during our long-term observations, 5 out of 32 samples have color measurement for the first time.

For the Centaur (517717) 2015 KZ120, a large number of observations indicate it is a red and elongated object with a rotation period of 10.7633 hours. Searching for its surface brightness profile and color at different rotational phase, we didn't find any cometary activity and significant color change at different faces. Moreover, our dynamical simulations show that the orbit of (517717) 2015 KZ120 was strongly affected by planets' gravity, with the median lifetime is only ~12 Myr.

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