When taking the M11 and starfield last night (see my other post), I noticed a trail in a frame, it moved in the next frame, and so on. My measurement indicates the trialing speed is about 15arcsec/sec. Wow, is it a geostationary satellite?
In the next two minutes I stopped the original sequence and the tracker, therefore captured the position of the object while the celestial objects were trialing in the image. Its image was still a point in every one of my 15s or 30s exposures. It was almost confirmed a geostationary satellite.
But wait! The point seemed to be moving laterally (DEC) across the exposures. Here goes the animation.
It moves at a speed of 30arcsec roughly every 2 minutes. This is trivial compared to its 15arcsec/sec speed around RA axis.
LIkely it was at an altitude similar to geostationary satellites, or 36000km. Given its brightness at such a distance, the size must be considerable.
Just, what could it be? Could it even be a near earth asteriod?
If it is an asteroid, its orbital inclination is nearly perfectly aligned with the earth's equator, not the ecliptic. This is somewhat unlikely.
A mysterious visitor
A mysterious visitor
Last edited by hhzhang on Wed Aug 19, 2020 12:04 pm, edited 1 time in total.
Re: A mysterious visitor
Finally I figured out it must be nothing but a geosynchronous satellite.
https://en.wikipedia.org/wiki/Geosynchronous_orbit
https://en.wikipedia.org/wiki/Geosynchronous_orbit
- Airconvent
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Re: A mysterious visitor
Yes...too many of these now. It used to be you are very excited to see them. But these days, astrophotographers and even serious astronomers hate it.
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United Federation of the Planets
Re: A mysterious visitor
Geosynchronous artificial satellites are still far less common than low orbit ones. I have encountered the latter in many of my subs but this is the only one doing geosync motion.Airconvent wrote: ↑Sun Sep 13, 2020 6:34 pm Yes...too many of these now. It used to be you are very excited to see them. But these days, astrophotographers and even serious astronomers hate it.