منبع: سایت کمان آسمانی
حتما" تمام علاقمندان به رويت هلال ماه علاقمند هستند تصويری از آقای جيمز استم را مشاهده نموده و در مورد ايشان اطلاعات بيشتری را بدست آورند. من در اين مورد با ايشان تماس گرفتم. ايشان هم لطف کرده و اطلاعات درخواستی را ارسال کردند.
I found a picture that my wife, Chris took while we were canoeing in Canada. It is a favorite of her's, so I will include it for you. It is more than 10 years old, and my beard has much more gray in it now.
What I consider the most important aspect of my record new moon sighting is the fact that it was the culmination of a 15 year GOAL. In 1981 I read in Guy Ottewell's Astronomical Companion about the 15 hour record, and that seeking early crescent records was a competition amongst amateur astronomers.
Since I had been fascinated by seeing the thin crescent for as long as I can remember (I had always wondered if it was visible the day before), I decided that if one knew _precisely_ where and when to look, then the 15 hour record could be broken.
I soon learned how extensive the calculations were (this was before computer software was widely available), and I was sure that I would make a mistake before finishing. So I "relearned" BASIC programming, bought my first computer, and developed programs to describe the Moon's characteristics and location. I got so involved that I accepted a position to teach BASIC programming at Berea College in Kentucky.
As I sought out thin crescents, I learned that Robert Victor at the University of Michigan broke the record with the sighting of a 13 1/2 hour moon with binoculars.
Maybe I wouldn't be able to beat that, but I could always seek to improve my own personal record. Then conditions came together favorably in December 1995, and three of us in southern Arizona planned to go after the record from various locations. All three of us were thwarted by clouds.
Then looking at January circumstances, I found that conditions were even more favorable than for December. The new moon for January would also usher in the month of Ramadan!
My computer programs were still as precise as anything commercial, but I still went about tweaking the code to improve results. The mount in my yard was perfectly placed to follow any image nearly to the theoretical horizon. And as the day approached, the weather was looking very good.
As a practice run, I observed the Friday morning old moon crescent well into the sky after the sun rose.
My technique for the Saturday new moon crescent was to set up the night before, and aim the telescope to the precise location where the Moon would be at 5:52 p.m. MST. Then I would watch certain stars pass through the eyepiece field, and adjust a little R.A. or Dec. or focus. I noticed that each of the seven stars that I chose required the scope to be adjusted slightly. This was a "discovery" of refraction changes due to temperature, etc.
A partly cloudy day often clears up after sunset in Tucson, so I was optimistic for the last couple of weeks. And when Saturday remained crystal clear all afternoon, I knew we would get the chance at our long sought "Very Young Moon." While running some errands in the car I was extremely defensive and cautious. I knew a bad wreck might make me miss the observation. I even kept checking my watch against clocks and the Sun.
We all (3 adults and 4 children) assembled as the Sun set, and the time approached for the 5 degree high Moon to slip into the fields of view of the C-8 and C-90. It stayed too bright to even attempt viewing through the binoculars or finders, right up to the time
(00:52:12) to engage the clock drive of the C-8. I did not see Beta Cap drift through the field of the 41' 50x C-8 eyepiece at 00:42:54, as I had expected, so there was doubt.
I decided to start searching through the eyepiece right at 00:52, while everyone else looked through the other glasses. My eyes are not that good, and I didn't want anyone else yelling out "There it is!" first. For five minutes I uttered disclaimers to my wife and neighbor, assuring them that there actually had been a real possibility of seeing something, and that they would indeed share in a world record if we were successful. Then it just appeared, as if to have come from behind something, as I slowly rotated the declination knob of the C-8. The crescent was close to the center of the field! At 00:57:06 I was able to confidently announce "I've got it!"
In a minute I was certain that none of us could see the thin sliver in binoculars, so we spent the next 16 minutes taking turns looking through the C-8, and watched the Moon set at 0.9 degrees (not factoring in the 34 arc minutes of refraction). Two of the children never did see the image in the telescope. One of my strategies had been to use children's eyes to maximize our potential. I'm now sure that experience is a far more important factor in making tough observations.
At the time of first visibility, the Moon's elongation from the Sun was 7.7 degrees. Percent lit was 0.6. Altitude was 4.3 degrees (without effects of refraction considered). AGE WAS 12 hours 07 minutes!
استفاده از مطالب فقط برای مقاصد غیرتجاری و با ذکر منبع بلامانع است. کلیه حقوق این سایت متعلق به تیم برنامه نویسی آویسا میباشد .