'UFO' over Sydney

[tgdavies (Tom)]

I just saw an interesting object in the sky:

Travelling West to East, around 50 degrees above the Southern horizon, travelling about two widths of my outstretched thumb in ten seconds.

It was invisible to the naked eye, except that it flashed roughly every 10 seconds -- some flashes were about the intensity of the brighter stars in the Southern Cross, some longer but dimmer. The flashes were brief, and white.

It looked as though it was moving too slowly to be an aircraft -- is there a satellite with that sort of flashing behaviour? (spinning and reflecting the sun?)

[dimithri86 (Dimithri)]

Helicopter?

[tgdavies (Tom)]

I suppose a helicopter flashing a bright searchlight around is *possible*, but:

- no sound,
- no navigation lights
- flashes were always the same length (very short) although not always the same intensity
- moved very predictably over a period of about five minutes
- flashes seemed to be in a regular pattern of intervals

[astroron (Ron)]

It is probably what I call a flasher,in other words a rotating satellite which has a number of reflecting surfaces and probable a larger solar panel which reflects more light than the smaller reflectors.
They are quite common to observers who study the sky regularly.
Nothing to be concerned about and definitely not a UFO.
Cheers

[tgdavies (Tom)]

Thanks Ron -- I seem to remember reading that the Iridium satellites tend to do that, for instance.

Definitely not concerned, just interested.

But with all due respect I'll call it a UFO until I know which satellite it was! :-)

Tom

[big_dav_2001 (Davin)]

I observed a similar object a few years ago... Further research revealed it to be a failed Russian satellite which was tumbling in its orbit, creating irregular flashes....

Davin

[astroron (Ron)]

Originally Posted by tgdavies

Thanks Ron -- I seem to remember reading that the Iridium satellites tend to do that, for instance.

Definitely not concerned, just interested.

But with all due respect I'll call it a UFO until I know which satellite it was! :-)

Tom

Go to heavens above and put in the time etc and you can find out.
Iridium Satellites don't normally tumble, they just have the reflection of the sun on their solar panels at a certain angle to the sun.
They just have a single solar panel, the rotating satellites have a number of reflective surfaces/panels.
Cheers.

[Atmos (Colin)]

I saw one of these in Melbourne a couple of months back, was kinda tempted to point my telescope at it as it was out at the time but I know I didn't have a chance in hell of tracking it!
As curious as to whether I could resolve a satellite with a 12" dob.

[astroron (Ron)]

Originally Posted by Atmos

I saw one of these in Melbourne a couple of months back, was kinda tempted to point my telescope at it as it was out at the time but I know I didn't have a chance in hell of tracking it!
As curious as to whether I could resolve a satellite with a 12" dob.

The ISS you can,I don't know any others.
You can track satellites with goto scopes that have fast slew and satellites in the data base.
You can also track them with a dob if you use a wide angle lens and especially if the are going away from you as it is normally just pushing the scope, you will probably have to adjust at times.
A pair of binoculars are good enough for the flashers as you can see the minor flashes before the bigger one.
Cheers

[Atmos (Colin)]

I know with my old Meade I could update it with recent satellite movements. I assume that I can with my Orion Dob (uses Synscan) but I haven't looked into it.
Problem is that I want to view it at 300x

[gary]

Originally Posted by astroron

The ISS you can,I don't know any others.
You can track satellites with goto scopes that have fast slew and satellites in the data base.
You can also track them with a dob if you use a wide angle lens and especially if the are going away from you as it is normally just pushing the scope, you will probably have to adjust at times.
A pair of binoculars are good enough for the flashers as you can see the minor flashes before the bigger one.
Cheers

Hi Ron,

Once you install the ServoCAT you will be able to track satellites with
your Argo Navis/ServoCAT combination on the 16" Dob.

There's some sophisticated software in the most current Argo Navis
and ServoCAT firmware release especially devoted to tracking them.

Up at Coonababran last month, one of the highlights was tracking them
on James Pierce's Argo Navis/ServoCAT equipped 14" SDM truss Dob.

That's a nice size scope to track them with as you don't have to stand
on a step ladder.

If you do try and track them from a larger scope up a ladder,
then you need to take care!

It's very exciting watching them appear to be stationary in the eyepiece
as all the background stars go zipping by. It's like in the movies
when they jump into hyperspace.

We observed a good handful early evening one night and everyone was
blown away. You actually feel your heart rate increase.

None of the ones we observed on that night had observable detail
and we were thwarted by cloud in the early morning to track the ISS
when it passed.

James is now hooked.

Best Regards

Gary Kopff
Managing Director
Wildcard Innovations Pty. Ltd.
20 Kilmory Place, Mount Kuring-Gai
NSW. 2080. Australia
Phone +61-2-9457-9049
Fax +61-2-9457-9593
sales@wildcard-innovations.com.au
http://www.wildcard-innovations.com.au

[sharptrack2 (Kevin)]

Interesting that someone mentions this... the past two nights, when I have been setting up on Jupiter, there has been a "flasher", right next to Jupiter. At first I thought it was an Iridium satellite, but none of the tracking sites suggested one at this altitude and azimuth. Tonight it came up at about the same time as yesterday, roughly 19:20 or so, and passed right across my view, it flashed 3 times at a rate of every 4-5 seconds, moving about the same speed as a slow satellite. This one was also moving west to east, and was only visible for 15-20 seconds.

I did not have a high enough magnification to see anything other than the flash, but I would guess it is a tumbler by the way it flashed. I can't help but wonder if it might be the Japanese observatory that was recently lost. I only mention it because it is the first time I've seen anything like this. Have seen an Iridium flare, and many, many known satellites. But this just looked like something out of control.

Will be watching for it again tomorrow night, maybe get the binos on to it.

[mjfitzhenry (Matthew)]

I saw that too tonight, around 7.20pm around Centaurus heading south. It flashes at random magnitudes and durations.

[koputai (Jason)]

If you keep an eye out about 20 to 45 degrees above the Western horizon at dusk, you will see 'flashers' or 'rollers'. They are quite common. I've seen a number of them every evening this week.

Cheers,
Jason.