Satellites and More – 2020 #1

Edmund Weiss (1837-1917) and many astronomers since have called asteroids “vermin of the sky”, but on October 4, 1957 another “species” of sky vermin made its debut: artificial satellites.  In the process of video recording stars for possible asteroid occultations, I frequently see satellites passing through my 17 × 11 arcminute field of view.

I’ve put together a video montage of satellites I serendipitously recorded during the first half of 2020.  Many of the satellites move across the field as “dashes” because of the longer integration times I need to use for some of my asteroid occultation work. A table of these events is shown below the video. The range is the distance between observer and satellite at the time of observation. North is up and east is to the left.

North is up and east is to the left; field size 17′ x 11′

Interestingly, three of the above satellites (7,9,18) are in retrograde orbits, that is their orbital inclination is > 90˚ and their east-west component of motion is towards the west instead of the east. However, I was surprised to find that two of the prograde orbiting satellites (5,6) appear to be orbiting retrograde! Both have orbital inclinations close to 90˚ (82.6˚ and 87.5˚, respectively), and both were in the western sky at northern declinations at the time of observation. But another satellite (8) with an orbital inclination of 82.5˚ at a southern declination in the southern sky at the time of observation exhibited the expected “barely” prograde motion. I suspect the ~0.5 km/s rotation of the Earth towards the east might have something to do with this “apparent retrograde” motion, but I was unable to find any reference that describes this situation.

Satellite #12 has an interesting story. It is the Inertial Upper Stage (IUS) used to launch USA-48 (Magnum), a classified DoD payload, from the Space Shuttle Discovery (STS-33).

In addition to these 18 satellites, I observed 7 geosynchronous satellites, shown below.

This non-operational Soviet communications satellite is a “tumbler”, meaning its changing orientation causes variation in its brightness, as shown below.

This non-operational communications satellite is also a tumbler, as seen in this light curve from a portion of the video.

SGDC-1 is a Brazilian geostationary communications satellite stationed over longitude 75˚ W, and in this video is followed by Star One C3 which will replace Brasilsat B3, also located over longitude 75˚ W.
Star One C3, a geostationary television satellite led by SGDC-1 and followed by GOES-16.
GOES-16, a geostationary weather satellite that is the primary weather satellite for the U.S., is stationed over longitude 75.2˚ W. Star One C3 precedes it in this video.
Intelsat 16 is a geostationary television satellite stationed over longitude 76˚ W currently.

There were four satellites I was unable to identify, shown in the video below. They were either classified satellites or, more likely, small pieces of space debris that only government agencies or contractors are keeping track of.

Unidentifiable satellites

Occasionally, I record other phenomena of interest. Meteors during this period are described here, and you will find a couple of other curiosities below.

An aircraft with flashing lights passed near the field containing UCAC4 376-101735 between 10:06:44 and 10:06:47 UT on 16 Apr 2020.
High energy particles zap the imaging chip from time to time, and here is one of the more interesting ones during the period, recorded on 9 May 2020 from 9:09:18 – 9:09:20 UT in the field of UCAC4 397-127754.

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

Satellite and Meteor Crossings 2019 #2

Edmund Weiss (1837-1917) and many astronomers since have called asteroids “vermin of the sky”, but on October 4, 1957 another “species” of sky vermin made its debut: artificial satellites.  In the process of video recording stars for possible asteroid occultations, I frequently see satellites passing through my 17 × 11 arcminute field of view.

I’ve put together a video montage of satellites I serendipitously recorded between August 9, 2019 and December 22, 2019.  Many of the satellite crossings are moving across the fields as “dashes” because of the longer integration times I need to use for some of my asteroid occultation work. A table of these events is shown below the video. The range is the distance between observer and satellite at the time of observation. North is up and east is to the left.

Satellites in higher orbits take longer to cross the field. In the next video, the originally geosynchronous satellite OPS 1570 (IMEWS-3, “Integrated Missile Early Warning System”) is barely visible until it exhibits an amazing sunglint around 3:41:22 UT.

I caught one meteor on October 6, 2019 at 9:57:43 UT. Field location was UCAC4 515-043597. The meteor was a Daytime Sextantid, as determined using the method I described previously in There’s a Meteor in My Image. The meteor even left a brief afterglow—a meteor train!

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

Satellite, Meteor, and Aircraft Crossings 2019

Edmund Weiss (1837-1917) and many astronomers since have called asteroids “vermin of the sky”, but on October 4, 1957 another “species” of sky vermin made its 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 serendipitously recorded between March 31, 2019 and July 12, 2019.  Many of the satellite crossings are moving across the fields as “dashes” because of the longer integration times I need to use for some of my asteroid occultation work. A table of these events is shown below the video. The range is the distance between observer and satellite at the time of observation.

Satellites in higher orbits take longer to cross the field. When possible, I’ve included graphs of brightness as a function of time for these slower-moving satellites after each individual video and corresponding table. When you watch the videos of geostationary satellites, you are actually seeing the rotation of the Earth as the line between you and the satellite sweeps across the stars as the Earth rotates!

Uncertain of identification
A tumbler with sun glints!
A high-amplitude tumbler! Satellite is no longer operational.

I caught one meteor on 4 Jan 2019 between 5:32:57 and 5:32:59 UT. Field location was UCAC4 419-017279. I’m pretty sure the meteor was a Quadrantid!

And two aircraft crossed my field: on 7 Dec 2018 1:40:05 – 1:40:13 UT (UCAC4 563-026131) and 26 Jun 2019 5:02:07 – 5:02:10 UT (UCAC4 291-144196).

And high energy particles (natural radioactivity or cosmic rays) “zing” my CCD/CMOS detector every once in a while. Here are a few examples: 5 Jan 2019 3:46:00 – 3:46:02 UT (UCAC4 473-001074); 20 Apr 2019 3:41:46 – 3:41:47 UT (UCAC4 501-062663); 30 Jun 2019 7:37:31 – 7:37:33 (UCAC4 354-179484) and 7:47:41 – 7:46:44 (TYC 6243-00130-1).

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

Satellite, Meteor, and Aircraft Crossings 2018

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 and some individual videos of satellites I’ve recorded between March 10, 2018 and November 24, 2018.  All of the events are shown below, with the boldface events being presented chronologically in the first video.  Both the NORAD and International designations are given for each satellite.  The range is the distance between observer and satellite at the time of observation.

UT Date
3-10-2018
3-25-2018
4-1-2018
4-2-2018
5-5-2018
7-6-2018
7-26-2018
7-31-2018
8-3-2018
8-23-2018
9-16-2018
10-21-2018 (2 satellites)
10-24-2018

Target Star
UCAC4 459-002239
TYC 621-45742-1
UCAC4 497-035454
UCAC4 416-092784
UCAC4 385-061427
N Sct 2018
UCAC4 429-110724
UCAC4 384-149264
UCAC4 362-194694
UCAC4 526-007192
UCAC4 316-210974
UCAC4 418-144100
UCAC4 302-215969

Satellite
SL-8 RB (Kosmos 726)
unknown space debris
unknown satellite
unknown satellite
unknown satellite
Ariane 5 RB (Payload A)
SL-8 RB (Kosmos 726)
Ariane 5 RB (VA209)
YURI 2A (BS-2A)
Kosmos 1092
SL-8 RB (Kosmos 80)
Galaxy 17 & NIMIQ 6
Sentinel 1B

Satellite
SL-8 RB (Kosmos 726)
unknown space debris
unknown satellite
unknown satellite
unknown satellite
Ariane 5 RB (Payload A)
SL-8 RB (Kosmos 726)
Ariane 5 RB (VA209)
YURI 2A (BS-2A)
Kosmos 1092
SL-8 RB (Kosmos 80)
Galaxy 17
NIMIQ 6
Sentinel 1B

Designation
7737; 1975-028-B
unknown
unknown
unknown
unknown
27946; 2003-043-B
7737; 1975-028-B
38780; 2012-051-C
14659; 1984-005-A
11326; 1979-030-A
1575; 1965-070-F
31307; 2007-016-B
38342; 2012-026-A
41456; 2016-025-A

Range & Direction
2,199.9 km SE
unknown SE
unknown SE
unknown NE
unknown NE
34,141.7 km NE
1,483.2 km SE
18,153.7 km NE
39,042.5 km NE
1,870.9 km NE
3,137.8 km NE
37,737.7 km E
37,736.3 km E
2,028.6 km NW

You’ll notice that sometimes the satellite crosses the field as a moving “dash”. That’s because sometimes I used longer exposure times to record a fainter target star.  A wind gust hit the telescope during the second event (3-25-2018).  The field is oriented North up and East to the left.  In this first video, you’ll notice that Sentinel 1B (the last event) has a unusual retrograde orbit (sun-synchronous) and is moving towards the NW.

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 video clip, you’ll see an unidentified piece of space debris, a very faint “dash” (due to integration) moving NE across the field from lower right to upper left, recorded on May 5, 2018 UT.

Next, we see a Ariane rocket body used to hoist SMART-1 towards the Moon and the Insat 3E and eBird 1 towards their geostationary orbits.  This recording was made on July 6, 2018 UT.  The rocket body is traveling NE (mostly east).  The light curve below the video suggests the possibility of some tumbling motion, but the satellite is faint and the photometry noisy.

And here is a rapidly tumbling (but low amplitude) Ariane rocket body, observed on July 31, 2018 UT and traveling NE.

Here is a no-longer-operational Japanese communications satellite named Yuri 2A, launched in 1984 and captured here on August 3, 2018 UT.  It is traveling NE (mostly east) and shows a beautiful long-period large-amplitude light curve.

Finally, we see not one but two geostationary communication satellites, Galaxy 17 (first and fainter) and NIMIQ 6 moving east across the field (as my telescope tracks westward to follow the Earth’s rotation), captured here on October 21, 2018 UT.  Galaxy 17 exhibits no discernible rotation, but NIMIQ 6 shows a low-amplitude long-period change in brightness.

Next we turn to three telescopic meteors I recorded on June 4, July 7, and September 11, 2018 UT.

UT Date
6-4-2018
7-7-2018
9-11-2018

Target Star
UCAC4 408-094611
UCAC4 275-188730
UCAC4 399-093188

Constellation & Direction
Scutum, SSE
Sagittarius, SW
Scutum, NNE

Here these meteors are presented in a video montage.

I even captured an airplane crossing the field on August 22, 2018 UT:

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

Satellite (and Meteor ) Crossings 2017-2018

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 June 21, 2017 and October 20, 2017.  The component events are presented chronologically as follows:

UT Date
6-21-2017
8-15-2017
9-4-2017
9-5-2017
9-12-2017
10-20-2017 (2 satellites)

Target Star
Tycho 5723-663-1
Tycho 1668-1258-1
Tycho 1281-225-1
UCAC4 553-20591
Tycho 5731-996-1
Tycho 6289-1504-1

Asteroid
798 Ruth
30981(1995 SJ4)
34532 (2000 SO213)
1294 Antwerpia
85985 (1999 JW)
25036 Elizabethof

You’ll notice that sometimes the satellite crosses the field as a moving “dash”.  That’s because sometimes I used longer exposure times to record a fainter target 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 video clip, you’ll see a slow-moving “tumbler” satellite moving from right to left across the top of the field.

UT Date
8-25-2017

Target Star
Tycho 676-828-1

Asteroid
179462 (2002 AJ202)

 

On January 10th of this year, I figured out how to identify satellites crossing the telescope field of view using the amazing program Guide 9.1, which I use for all my observatory research work.  On March 4th, I was hoping to be the first to record the asteroid 3706 Sinnott passing in front of a star.  This asteroid is named after Sky & Telescope Senior Editor Roger Sinnott, whom I had the good fortune to work with in writing the article “A Roll-Down-Roof Observatory” in the May 1993 issue of Sky & Telescope, p. 90.  Roger is amazing.  He took an article that I had written and edited it in a way that only lightly touched my original text yet ended up saying what I wanted to say even better than I was able to say it myself.  The mark of a great editor!  Anyway, I’m sure Roger remembers me and I was looking forward to giving him the news that I had observed the first stellar occultation by “his” asteroid.  Alas, it was not to be, because, as so often happens, the too-faint-to-be-seen asteroid passed either above or below the target star.  The consolation prize, however, was recording a third stage Long March Chinese rocket booster (CZ-3B R/B; NORAD 43004U; International # 17069D) passing through the field.  This rocket launched on November 5, 2017, and added two satellites to China’s Beidou positioning network.  As you can see in the light curve below, the rotation period of the rocket booster is a bit longer than the 19 seconds of usable video I had.

UT Date
3-4-2018

Target Star
UCAC4 556-42881

Asteroid
3706 Sinnott

 

Once in a great while, I record a telescopic meteor.  Here are two.

UT Date
7-15-2017
3-4-2018

Target Star
Tycho 6269-2747-1
UCAC4 561-14746

Asteroid
17136(1999 JE82)
6890 Savinykh

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

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