Monday, January 31, 2005

2000-1-12, 20:30-22:30 (At home, with Ranger)

This a real wonderful night, the seeing is exceptional!!!

When I went back home after the prayer meeting, I saw the moon from my windows. I setup the Ranger within one minute and begin observing. The cresent moon was so good in my 15x field of view!!! I could see the whole disc, with the help of Earthshine. I couldn't help to ask my little sister to look into my eyepiece! "Woww!!", was her response. I understand that she appreciated it. I pumped it up to 75x with the Powermate, she looked and wonder how nice the view was. Excellent! I pushed it further up to 150x with the 2x Barlows with the original setup, making it very long, but the view was so good!

I called my parents in and my father found it difficult to catch the view into the eyepiece, maybe the eye-relief was too much in that kind of setup. I replaced it with a 20mm eyepiece to make a magnification of 120x with the Powermate, I knew he could find the view finally when I heard the voice "woww..." from him. My mother got next but she didn't make a woww... voice and we guess that she couldn't see it. But that's not the case, she seemed not so excited as us, she described the view to us, showing that she could really saw the image in the eyepiece. Of course, she appreciated the view, but she found nothing special about it. I guess it's because she didn't know how far out there the moon really was.

I continue to watch the moon, try different magnifications, including the weird 381x and even 762x... To my surprise, the Ranger could hold with 381x actually but of course, it brought no further detail. 762x generated a too small exit-pupil, I could see nothing except my own eyes. Not bad. I keep watching the moon at 75x, finding it's the optimal for tonight. The moon sinked without a notice.

My next target was Jupiter, but I have to wait ten minutes or so after the moon disappeared.

The view of Jupiter was so good tonight, it's the best view I had so far. With 75x, I could detected three belts clearly. Pushing it up to 120x (20mm/5) or 150x (6.3mm/2) revealed the fourth belts. That's the first time I could detect four belts. Actually, I suspect I could see five of them, but I ain't so sure about that. I suspect I could also detect the GRS together with some largest festoons on the thick belt in the "lower" portion of the planet disc. It's so nice that I kept on looking it for 20 minutes or even more, before it went out of the view. The Jupiter disappeared below the tall build in front of me, and I discovered that first when the resolution of the image dropped suddenly.

After all, I found that the Celestron Plossl was the worst among my three eyepieces. The Sirius Plossl was not bad, but a dim ghost could be seen on axis. The quality of the image in the Sirius Plossl was not bad, very much comparable to the Tele Vue Plossl. But I could see no ghost in the Tele Vue Plossl. At first, I guess that the Celestron Plossl plus the Orion Shorty barlows could give some pressure to the Tele Vue Plossl plus the Powermate because there were fewer element in the Orion Shorty, but I found it NOT to be the case. Even the Powermate plus the Sirius Plossl showed me more than the Celestron Plossl alone, i.e. with half number of elements.

I was waiting for the Saturn, it took me the time to write the above paragraphs.

It began to pop into the view at 22:00, the ring opened nicely at a large angle. But I couldn't see the Cassini division, I could at best, say that I could barely detect it. However, I would try to see if I could see it next time. I didn't consider it is success this time.

The little Ranger is more capable than I once think.

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