ONSET(Optical-NIR Solar Eruption Explore Telscope) is researched and manufactured by NIAOT for Nanjing university,which was installed at Fu-Xian Lake base of Yunnan observatory in 2011.

　　 Since trial observation,solar chromosphere and white image with high resolution was obtained.

Recently first all disc and local region solar image at wavelength 1083nm was sucessfully obtained.

　　 ONSET will be used to explore the solar eruption in the solar atmosphere layer between the chromosphere and corona with high optical and NIR resolution,which is working on two observing modes(all disc and local region).

 ONSET is composed of four tubes：

1）：f275mm vacuum tube with a 1083nm/0.05nm Lyot filter。

2）：f275mm vacuum tube with a 656.3nm/0.025nm Lyot filter。

3）：f200mm vacuum tube working on 425nm and 360nm by use of corresponding interference filter of 1.5nm FWHM.

4）：f140mm guiding tube。

　　 All tubes are placed in a compact equatorial mounting.

first all disc solar image at wavelength 1083nm 

first local region solar image at wavelength 1083nm