Asteroid 18590
Asteroids are small rocky bodies or minor planets which orbit the sun, normally in the so-called
asteroid belt between Mars and Jupiter. This area is about 180 to 270 million miles from the Sun.
Literally thousands of asteroids are known ranging in size from almost 600 miles in diameter to just a
few meters. It is unclear how asteroids formed, but it is thought that they are the remains of larger
bodies that broke up long ago, probably while the planets were being formed.
On March 25, 2009, the magnitude 16.1 asteroid 18590 passed visually near the 12th magnitude
galaxy, NGC5211. Asteroid 18590 is relatively small, being only about 7 km in diameter. Images of
this event were taken by J.W. Brinsfield (http://www.viacapotesky.com/) with an Apogee Alta U6
camera and covered a 6 hour period. The images were provided to me by my friend, Fred Pilcher,
who is active in the Minor Planet Society.
The GIF animation shown below was created as follows…..
1. Selection of images…. A total of 82 FIT images were provided. Those showing elongation or a
relatively bright background were discarded. This left 52 images. Every other image was selected
for the animation. The selected 26 images cover a period of about 4 hours.
2. Alignment….The FIT images were aligned with CCDStack . They were then collectively cropped,
digitally developed and saved at TIFF images. This alignment step proved to be critical to reducing
“jitteriness” in the animation. Without it, there was some movement of the frames within the animation.
3. Further digital development…. Images Plus digital development was then applied to all the
images. The resulting images were saved as TIFF files.
4. Photoshop development….. PS “actions” were used to apply curves, adjust levels, apply noise
reduction (Noise Ninja), convert to 8-bit, and save as GIF files. Use of "actions" proved to be very
helpful in applying repeated edits to each of the 26 frames. Each image was then individually edited
to remove most cosmic ray hits and other noise.
5. Animation….GIF Movie Gear was used to create the animation. File size was improved by
reducing the size of the images and by reducing the number of colors used from 64 to 32. These
measures can reduce the file size from over 4MB to less than 1MB.
asteroid belt between Mars and Jupiter. This area is about 180 to 270 million miles from the Sun.
Literally thousands of asteroids are known ranging in size from almost 600 miles in diameter to just a
few meters. It is unclear how asteroids formed, but it is thought that they are the remains of larger
bodies that broke up long ago, probably while the planets were being formed.
On March 25, 2009, the magnitude 16.1 asteroid 18590 passed visually near the 12th magnitude
galaxy, NGC5211. Asteroid 18590 is relatively small, being only about 7 km in diameter. Images of
this event were taken by J.W. Brinsfield (http://www.viacapotesky.com/) with an Apogee Alta U6
camera and covered a 6 hour period. The images were provided to me by my friend, Fred Pilcher,
who is active in the Minor Planet Society.
The GIF animation shown below was created as follows…..
1. Selection of images…. A total of 82 FIT images were provided. Those showing elongation or a
relatively bright background were discarded. This left 52 images. Every other image was selected
for the animation. The selected 26 images cover a period of about 4 hours.
2. Alignment….The FIT images were aligned with CCDStack . They were then collectively cropped,
digitally developed and saved at TIFF images. This alignment step proved to be critical to reducing
“jitteriness” in the animation. Without it, there was some movement of the frames within the animation.
3. Further digital development…. Images Plus digital development was then applied to all the
images. The resulting images were saved as TIFF files.
4. Photoshop development….. PS “actions” were used to apply curves, adjust levels, apply noise
reduction (Noise Ninja), convert to 8-bit, and save as GIF files. Use of "actions" proved to be very
helpful in applying repeated edits to each of the 26 frames. Each image was then individually edited
to remove most cosmic ray hits and other noise.
5. Animation….GIF Movie Gear was used to create the animation. File size was improved by
reducing the size of the images and by reducing the number of colors used from 64 to 32. These
measures can reduce the file size from over 4MB to less than 1MB.
| Asteroid 18590 passing visually near galaxy NGC5211. The asteroid moves from right to left near the center of the frame. Click on this image for full size. It takes about 30 seconds to fully load. |