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ASTRO: NEO 2014 CU13 The Movie
Near earth asteroid 20114CU13 passed by us March 11 about 5 hours UT.
Since it was forecast (and really was) cloudy at that time I tried for it just before dawn the night before, March 10. There were some clouds but they soon cleared. I was able to get 30 minutes of data before dawn started to brighten the sky. First few frames were dimmed a bit by the clouds but otherwise it worked well. The asteroid was about 1.2 million miles from us at the time of the movie and about 1.1 million miles at closest approach the following night so the difference is rather small. We had three other asteroids pass by, one only 38,000 miles out the last few days but all were either clouded out or too far south or lost in the sun from my view. 2014CU14 was discovered exactly one month ago, February 11, 2014. It is quite large so it is good it kept its distance. Estimates put it at about 200 meters in diameter. The movie consists of 30 one minute frames and covers about 32 minutes of time as it takes a few seconds to download each frame. The frames were taken at 1.5" per pixel then downsized to 3" per pixel to reduce the size of the animation but keep the full frame. Due to the bright moon not far away the image is rather noisy which greatly enlarged the file. During the imaging run the mount was tracking on the asteroid rather than the stars. No alignment of the frames was needed. While its motion was calculated from orbital data a couple days prior to the night the earth hadn't perturbed the orbit to any great extent so the values I used to offset from the sidereal rate were sufficient to keep the asteroid near the center of the frame. Computers and today's robotic mounts make such feats rather easy to accomplish. Not long ago even the pros had a hard time doing this type of tracking. The asteroid moved about 1 minute of arc per minute of time. So the star trails pretty well define 1 minute of arc. 14" LX200R @ f/10, 30x1' binned 3x3, STL-11000XM, Paramount ME Movie is too big for USENET and it's klutzy 7 bit attachments so I've just provided a link to the animation. The first frame is attached as a JPG. http://www.prairieastronomyclub.org/...2014CU13-3.wmv Rick -- Prefix is correct. Domain is arvig dot net |
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ASTRO: NEO 2014 CU13 The Movie
Rick,
without the ability of the mount to track on the asteroid that would have been almost impossible. It's speed is quite impressive. Stefan "Rick Johnson" schrieb im Newsbeitrag ... Near earth asteroid 20114CU13 passed by us March 11 about 5 hours UT. Since it was forecast (and really was) cloudy at that time I tried for it just before dawn the night before, March 10. There were some clouds but they soon cleared. I was able to get 30 minutes of data before dawn started to brighten the sky. First few frames were dimmed a bit by the clouds but otherwise it worked well. The asteroid was about 1.2 million miles from us at the time of the movie and about 1.1 million miles at closest approach the following night so the difference is rather small. We had three other asteroids pass by, one only 38,000 miles out the last few days but all were either clouded out or too far south or lost in the sun from my view. 2014CU14 was discovered exactly one month ago, February 11, 2014. It is quite large so it is good it kept its distance. Estimates put it at about 200 meters in diameter. The movie consists of 30 one minute frames and covers about 32 minutes of time as it takes a few seconds to download each frame. The frames were taken at 1.5" per pixel then downsized to 3" per pixel to reduce the size of the animation but keep the full frame. Due to the bright moon not far away the image is rather noisy which greatly enlarged the file. During the imaging run the mount was tracking on the asteroid rather than the stars. No alignment of the frames was needed. While its motion was calculated from orbital data a couple days prior to the night the earth hadn't perturbed the orbit to any great extent so the values I used to offset from the sidereal rate were sufficient to keep the asteroid near the center of the frame. Computers and today's robotic mounts make such feats rather easy to accomplish. Not long ago even the pros had a hard time doing this type of tracking. The asteroid moved about 1 minute of arc per minute of time. So the star trails pretty well define 1 minute of arc. 14" LX200R @ f/10, 30x1' binned 3x3, STL-11000XM, Paramount ME Movie is too big for USENET and it's klutzy 7 bit attachments so I've just provided a link to the animation. The first frame is attached as a JPG. http://www.prairieastronomyclub.org/...2014CU13-3.wmv Rick -- Prefix is correct. Domain is arvig dot net |
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ASTRO: NEO 2014 CU13 The Movie
The Paramount with The Sky 6 makes it very easy. Just hit the button to
add orbit offsets to the tracking rate and it makes the calculations. It does turn off if you give any other command to the mount and the button is on a menu I have to pull down so I have to center a tad ahead of the asteroid then find the menu and hit the button. Other than that task its simple to do. Will track satellites the same way but since it doesn't go through the meridian that's not all that useful. I've not tried it. Rick On 3/17/2014 4:28 PM, Stefan Lilge wrote: Rick, without the ability of the mount to track on the asteroid that would have been almost impossible. It's speed is quite impressive. Stefan "Rick Johnson" schrieb im Newsbeitrag ... Near earth asteroid 20114CU13 passed by us March 11 about 5 hours UT. Since it was forecast (and really was) cloudy at that time I tried for it just before dawn the night before, March 10. There were some clouds but they soon cleared. I was able to get 30 minutes of data before dawn started to brighten the sky. First few frames were dimmed a bit by the clouds but otherwise it worked well. The asteroid was about 1.2 million miles from us at the time of the movie and about 1.1 million miles at closest approach the following night so the difference is rather small. We had three other asteroids pass by, one only 38,000 miles out the last few days but all were either clouded out or too far south or lost in the sun from my view. 2014CU14 was discovered exactly one month ago, February 11, 2014. It is quite large so it is good it kept its distance. Estimates put it at about 200 meters in diameter. The movie consists of 30 one minute frames and covers about 32 minutes of time as it takes a few seconds to download each frame. The frames were taken at 1.5" per pixel then downsized to 3" per pixel to reduce the size of the animation but keep the full frame. Due to the bright moon not far away the image is rather noisy which greatly enlarged the file. During the imaging run the mount was tracking on the asteroid rather than the stars. No alignment of the frames was needed. While its motion was calculated from orbital data a couple days prior to the night the earth hadn't perturbed the orbit to any great extent so the values I used to offset from the sidereal rate were sufficient to keep the asteroid near the center of the frame. Computers and today's robotic mounts make such feats rather easy to accomplish. Not long ago even the pros had a hard time doing this type of tracking. The asteroid moved about 1 minute of arc per minute of time. So the star trails pretty well define 1 minute of arc. 14" LX200R @ f/10, 30x1' binned 3x3, STL-11000XM, Paramount ME Movie is too big for USENET and it's klutzy 7 bit attachments so I've just provided a link to the animation. The first frame is attached as a JPG. http://www.prairieastronomyclub.org/...2014CU13-3.wmv Rick -- Prefix is correct. Domain is arvig dot net |
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