Monday, January 31, 2005

29-June-2003: Tin Kee with 25" and Ranger

The transparency has been very good these days, the seeing has been good as well despite there was nice breeze blowing which ease the hot wet summer weather.

We arrived at 6:30p and we setup the 25" scope at around 6:45p. The scope was stored in several place. The secondary cage and the primary mirror was stored indoor. The rocker box plus the primary cage was stored indoor as well, but just outside the roof for observation.

We moved the primary mirror up to the roof and it was very heavy such that two persons can barely do it. This huge chunk of glass was a monster. The secondary cage was much lighter and can be handled by one person. That's important for we got to set it up on the top of the tall tall truss tube.

After the EQ platform, the secondary cage and the mirror was transported to the roof, we moved the monster size component. It was placed on top of a big trolley but we got to move it with five persons.

Setting it up was fun, but time consuming, however it worths. The first installation was not done very nicely and the primary has to be moved out and re-install to get enough room for collimation.

In short, with the 25", all clusters become open clusters. Even the highest density globular was resolved to the core at moderate magnification. The light gathering power and resolving power of the 25" is well shown even with lots of light pollution around.

For nebula and galaxies, it does not show well due to the light pollution, not much color can be discerned, again due to the light pollution, and so we said only 30-40% of the power of the 25" is shown.

All the star clusters, globular or open, show better than photograph since you can see it 3 dimensional. Staring at an object will reveal stars which are not shown clearly in the first glance, and the static cluster looked vivid and alive due to this reason.

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