OzEclipse
29-05-2022, 01:42 PM
The asteroid designated, 1989 JA, has been flying by Earth this week. It was closest over the last two nights, 27/28 May. It was closest Friday night(May 27) but it was cloudy & raining here. Last night (May 28) was clear with a bit of moisture in the air blurring the images.
It's distance from Earth when this sequence was taken was about 4,097,000 km from Earth. That's approximately ten times the distance to the Moon. The bright star top right is HIP 50070 in the constellation of Vela, 9 degrees north west of Eta Carina. It was moving fast with a motion against background stars calculated around 40 arc sec per minute.
In my photograph, I've measured the motion to be more like 1.9 degrees per hour but I can't explain the discrepancy. Although faint, I was definitely on the right target. When chasing fast moving close objects, I always check asteroid positions in my planetarium programs against ephemerides from both the Harvard Minor Planet Centre and NASA Horizons orbit calculators making sure all four sources give consistent results.
https://joe-cali.com/astronomy/astrophotography-2/2022/1989-JA-3.gif
It's distance from Earth when this sequence was taken was about 4,097,000 km from Earth. That's approximately ten times the distance to the Moon. The bright star top right is HIP 50070 in the constellation of Vela, 9 degrees north west of Eta Carina. It was moving fast with a motion against background stars calculated around 40 arc sec per minute.
In my photograph, I've measured the motion to be more like 1.9 degrees per hour but I can't explain the discrepancy. Although faint, I was definitely on the right target. When chasing fast moving close objects, I always check asteroid positions in my planetarium programs against ephemerides from both the Harvard Minor Planet Centre and NASA Horizons orbit calculators making sure all four sources give consistent results.
https://joe-cali.com/astronomy/astrophotography-2/2022/1989-JA-3.gif