Satellite Crossings 2016-2017

Edmund Weiss (1837-1917) and many astronomers since have called asteroids “vermin of the sky”, but since October 4, 1957 another “species” of sky vermin made their debut: artificial satellites.  In the process of video recording stars for possible asteroid occultations, I frequently see satellites passing through my ~¼° field of view.

I’ve put together a video montage of satellites I’ve recorded between December 14, 2016 and August 5, 2017.  The component events are presented chronologically as follows:

UT Date
12-14-2016
1-15-2017
5-5-2017
6-7-2017
6-19-2017
7-25-2017 (2 satellites)
8-5-2017

Target Star
UCAC4 538-7253
Tycho 586-1051-1
Tycho 1422-911-1
Tycho 4997-136-1
Tycho 6799-309-1
Tycho 666-190-1
UCAC4 548-7392

Asteroid
2485 Scheffler
19807 (2000 SE16)
71612 (2000 EH12)
11133 Kumotori
68112 (2000 YC143)
491 Carina
151 Abundantia


In all cases, the asteroids were too faint to be recorded.  And, in all cases, the target star was not occulted by the asteroid (a miss).  In the final event, the satellite passed right over the target star (9:40:11.679 UT) during the period of time the event would be most likely to occur (9:40:10 ± 3 s)!  Fortunately, the seeing disc of the target star was never completely obliterated by the passing satellite, so I was able to determine unequivocally that the asteroid missed passing in front of the star from my location on Spaceship Earth.

Here’s a graph of the brightness of UCAC4 548-7392 during the last video clip.  You can definitely see the close appulse of the satellite with the star!

In general, the slower the satellite is moving across the field, the higher is its orbit around the Earth.  One must also consider how much of the satellite’s orbital motion is along your line of sight to the satellite.  In the following montage of two video clips, the first satellite is very slow moving and thus most likely in a very high orbit.  The second video clip shows a satellite that is quite faint.  Again, the asteroids are too faint to be recorded and no asteroid occultation event occurred.

UT Date
5-14-2017
6-8-2017

Target Star
Tycho 5011-133-1
Tycho 5719-308-1

Asteroid
190471 (2000 DG27)
321656 (2010 BM90)

References
Hughes, D. W. & Marsden, B. G. 2007, J. Astron. Hist. Heritage, 10, 21

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