Author Topic: Starlink satellites on a murky night  (Read 171 times)

0 Members and 1 Guest are viewing this topic.

MarkS

  • O. A. S.
  • Galaxy Cluster
  • *
  • Posts: 7294
Starlink satellites on a murky night
« on: Jan 19, 2020, 19:43:24 »
I decided to do some imaging tonight (my hand has recovered sufficiently from the operation) but the sky quality was pretty bad - very murky with an SQM reading of 20.6 - so I would describe this as a practice run.

Walking out to the obsy at 18:20 I noticed a train of bright objects moving through the sky - 10 of them in all.  I checked on Heavens Above and sure enough it was Starlink - launch 3.  Apparently there should have been lots more but I just caught the final 10.

Here are the details from Heavens Above (location Greenwich):
https://www.heavens-above.com/AllPassesFromLaunch.aspx?lat=51.4934&lng=0.0098&loc=Greenwich&alt=0&tz=GMT

The sequence I saw ended with Starlink AN and they were all 10-15secs apart. Plenty more opportunities in the early evening over the coming days.  Well worth checking out because visually they actually look quite spectacular and it gives us an unfortunate and terrible preview into the future.

Mark
« Last Edit: Jan 19, 2020, 19:55:22 by MarkS »

Carole

  • O. A. S.
  • Galaxy Cluster
  • *
  • Posts: 8321
    • Carole's images
Re: Starlink satellites on a murky night
« Reply #1 on: Jan 20, 2020, 09:15:52 »
Great to hear you are improved enough to start getting back into the "saddle".

It makes grim prospects.  I have been in a conversation on Astrobin about it, and we have all signed the petition I attached on another thread.  During which time I did some internet searching and found an E mail address for ESO who had got involved (European Southern Observatory), it was the Communications Officer, so I E mailed him telling him about all the 1000s of amateur astronomers and imagers who will be affected, not to mention the retailers, manufacturers and astro holiday places like Ollys and Astrofarm etc who might lose business if people gave up astronomy because of it. 

Upshot was he skyped me and we had a face to face conversation about it.

He says the professional astronomers have been in communication with Space Ex who are experimenting with a non-reflective coating on one of the satelittes, but are worried about it causing over heating. 

He suggested we got all the retailers involved since he felt loss of business would be a bigger influence than loss of hobby, and so I am starting to contact the same, but it would be good if others could help.
So far only managed to contact Deep Sky West who have yet to reply, and since then I have been back and forth to Swanley (Dave who comes to Cairds) for a mini astro weekend where he has Bortle 6 skies and no tree in the way of Orion.  Am on my 4th and last day there tonight.

Any further ideas Mark and any-one else.  I can see imaging and Astronomy being a no-go in a few years time unless software can deal with all the satelitte trails. 

Carole




MarkS

  • O. A. S.
  • Galaxy Cluster
  • *
  • Posts: 7294
Re: Starlink satellites on a murky night
« Reply #2 on: Jan 21, 2020, 11:29:38 »
Depending on cloud cover, tonight provides another good opportunity to see them.  The spacing between them has increased but from 17:30 to 18:30 sixty Starlink satellites will pass over.  The first 40 satellites come in a 10 minute period but they might be difficult to see against the dusk sky.

Details here:
https://www.heavens-above.com/AllPassesFromLaunch.aspx?lat=51.4934&lng=0.0098&loc=Greenwich&alt=0&tz=GMT

The early ones will come up close to Venus but this will increase to approx. 20 degrees left of Venus.

They pass over for a second time from 19:00 onwards but they will be lower in the sky and dimmer.

Mark

MarkS

  • O. A. S.
  • Galaxy Cluster
  • *
  • Posts: 7294
Re: Starlink satellites on a murky night
« Reply #3 on: Jan 21, 2020, 23:23:11 »
Here's the video:  https://drive.google.com/open?id=1uq3WlcLf7zalrUSirxJRGyMw9qLRfsh8

Tuesday 21-Jan-2020 starting at around 17:29 GMT and finishing 11 minutes later.
Nikon 35mm lens on Nikon Z6 at ISO 800 F/5.6
135 exposures of 5sec each, pushed 2.5 stops in processing.

A train of 40 Starlink satellites passed across the sky during this time.  Visually I observed a line of 15 satellites in the sky simultaneously.  At magnitude 3.0 they were pretty bright.

For best quality, download the video file and play it locally on your device.

Mark
« Last Edit: Jan 22, 2020, 00:10:15 by MarkS »

Roberto

  • O. A. S.
  • Star Class
  • *
  • Posts: 151
    • Astrobin
Re: Starlink satellites on a murky night
« Reply #4 on: Jan 22, 2020, 17:29:56 »
This is shocking!  It looks like anti-aircraft tracers!  :!

The Thing

  • Mr October
  • O. A. S.
  • Galaxy Class
  • *
  • Posts: 2826
  • The OAS International Branch
Re: Starlink satellites on a murky night
« Reply #5 on: Jan 23, 2020, 09:36:57 »
This is shocking!  It looks like anti-aircraft tracers!  :!

ditto - nasty Are we sure it's not a Tie fghter having a go at an xWing? Might be a cover story put out by Musk as part of the 'government conspiracy' or maybe its just a ploy by flat earthers to stop astronomers looking at the heavens and bleating on about round planets and stars being a the centre of solar systems. I think we should be told!

Meanwhile maybe some clever mathematician type bod can come up with a neural network algorithm thing like the new Star Remover tool to remove the trails. I suspect they will appear in every sub and several subs as they go round and round once they are spread out. I wonder how many will be sharing each final orbit?
¯\_(ツ)_/¯ (Gallic shrug :))
My Website AstroManche

MarkS

  • O. A. S.
  • Galaxy Cluster
  • *
  • Posts: 7294
Re: Starlink satellites on a murky night
« Reply #6 on: Jan 23, 2020, 10:01:13 »
This is shocking!  It looks like anti-aircraft tracers!  :!

Meanwhile maybe some clever mathematician type bod can come up with a neural network algorithm thing like the new Star Remover tool to remove the trails. I suspect they will appear in every sub and several subs as they go round and round once they are spread out. I wonder how many will be sharing each final orbit?

Phase 1 will have 72 orbits with 22 satellites in each, making 1584 in total.  Assuming they are equally spaced that means in any one orbit there will be a satellite every 4 minutes - not one every 15sec like my video.  But the final total could be up to 42,000 satellites!!

Look at the Wiki: https://en.wikipedia.org/wiki/Starlink_(satellite_constellation)

Even so, it won't be an issue for deep-sky-object imaging because we routinely remove satellite trails with sigma stacking - we do this anyway with the geostationary satellites that afflict imaging of Orion.  Once the sun is sufficiently below the horizon we won't see the Starlink satellites because they'll be in the earth's shadow - just like the ISS which is never visible deep in the night in Winter.  The Summer months will be a problem though because just like the ISS they'll be visible all night long.

It's the astro-landscape folk that will be most affected because they take wide views and they don't tend to take sufficient exposures to remove the trails by sigma stacking.

Mark