Fast Flashing 2004-021B

Just as dawn was starting to set in this morning, I was able to observe the
recently launched rocket booster for Cosmos 2406, labeled as SL-16 R/B on the
Heavens-Above Web Site. (2004-021B or 28353.)

At 4:26 AM (9:46 UT June 20th) it passed through Cygnus and Cepheus nearly
overhead from my yard. I used 7X35 binoculars to spot it, since it was bright
enough for only 1st - 2nd magnitude stars to be visible.

The rocket was flashing very rapidly, very roughly twice a second, going from
2nd or 3rd magnitude down to 4th or 5th (it was tough to make a good estimate).


This is a very interesting object and I hope to keep track of it and see it
under darker skies soon!

Paul Z
Indianapolis, IN

I have been reading some posts on the SeeSat-L list, and even though I
subscribed to this list some weeks ago I can't seem to send email to the group.
An error message comes back telling me that I have attachments or a text that
isn't working. I can't seem to fix the problem.

A recent message in that group says that no flashing was seen on a recent
pass from 04-021B, which took place after the one that I posted here Sunday.

I wanted to reply that when I first saw this object passing overhead through
Cygnus it seemed steady to me, but when it was lower in the north it seemed to
have a definite flash period. The estimate I made of twice per second is
extremely rough. I was observing it through handheld 7X35 binoculars with a lot
of dawn light already in the sky.

I hope that another observer sees a flash period with this object, so I don't
wind up thinking it was just my overactive imagination after a long night at
the telescope!

I also hope I can get my SeeSat-L problem fixed soon. I am definitely a
novice at satellite observing but would love to contribute some worthwhile data
and share any news.

Paul Z
Indianapolis, IN

I have been reading some posts on the SeeSat-L list, and even though I
subscribed to this list some weeks ago I can't seem to send email to the group.
An error message comes back telling me that I have attachments or a text that
isn't working. I can't seem to fix the problem.

A recent message in that group says that no flashing was seen on a recent
pass from 04-021B, which took place after the one that I posted here Sunday.

I wanted to reply that when I first saw this object passing overhead through
Cygnus it seemed steady to me, but when it was lower in the north it seemed to
have a definite flash period. The estimate I made of twice per second is
extremely rough. I was observing it through handheld 7X35 binoculars with a lot
of dawn light already in the sky.

I hope that another observer sees a flash period with this object, so I don't
wind up thinking it was just my overactive imagination after a long night at
the telescope!

I also hope I can get my SeeSat-L problem fixed soon. I am definitely a
novice at satellite observing but would love to contribute some worthwhile data
and share any news.

Paul Z
Indianapolis, IN

PZeller66 wrote:

A recent message in that group says that no flashing was seen on a recent
pass from 04-021B, which took place after the one that I posted here Sunday.

I wanted to reply that when I first saw this object passing overhead through
Cygnus it seemed steady to me, but when it was lower in the north it seemed to
have a definite flash period. The estimate I made of twice per second is
extremely rough. I was observing it through handheld 7X35 binoculars with a lot
of dawn light already in the sky.

I hope that another observer sees a flash period with this object, so I don't
wind up thinking it was just my overactive imagination after a long night at
the telescope!

I saw it on Monday morning, and my observations were similar to yours.
As it approached its apex it was about magnitude 2, and seemed to have
a slight, rapid pulsation in its magnitude; I thought there might have
been a thin layer of cloud in the way. Oddly, this pulsation was more
apparent to the naked eye than through binoculars. It wasn't until
after the bird passed its apex that the variation in magnitude became
more pronounced. It seemed to blink on and off approximately ninety
times per minute.

--Bill Thompson

PZeller66 wrote:

A recent message in that group says that no flashing was seen on a recent
pass from 04-021B, which took place after the one that I posted here Sunday.

I wanted to reply that when I first saw this object passing overhead through
Cygnus it seemed steady to me, but when it was lower in the north it seemed to
have a definite flash period. The estimate I made of twice per second is
extremely rough. I was observing it through handheld 7X35 binoculars with a lot
of dawn light already in the sky.

I hope that another observer sees a flash period with this object, so I don't
wind up thinking it was just my overactive imagination after a long night at
the telescope!

I saw it on Monday morning, and my observations were similar to yours.
As it approached its apex it was about magnitude 2, and seemed to have
a slight, rapid pulsation in its magnitude; I thought there might have
been a thin layer of cloud in the way. Oddly, this pulsation was more
apparent to the naked eye than through binoculars. It wasn't until
after the bird passed its apex that the variation in magnitude became
more pronounced. It seemed to blink on and off approximately ninety
times per minute.

--Bill Thompson

I saw it on Monday morning, and my observations were similar to yours.
As it approached its apex it was about magnitude 2, and seemed to have
a slight, rapid pulsation in its magnitude; I thought there might have
been a thin layer of cloud in the way. Oddly, this pulsation was more
apparent to the naked eye than through binoculars. It wasn't until
after the bird passed its apex that the variation in magnitude became
more pronounced. It seemed to blink on and off approximately ninety
times per minute.


Thanks for the confirmation! I was starting to think that my eyes were
playing tricks on me early that morning. This is a really interesting rocket to
track.

I'm assuming that the constant look to its brightness was because of it's
orientation. Maybe I was first seeing it at a nearly right angle to its axis of
rotation, and then when it was closer to the horizon I was seeing it more from
the side, tumbling end over end.

Paul Z
Indianapolis, IN

I saw it on Monday morning, and my observations were similar to yours.
As it approached its apex it was about magnitude 2, and seemed to have
a slight, rapid pulsation in its magnitude; I thought there might have
been a thin layer of cloud in the way. Oddly, this pulsation was more
apparent to the naked eye than through binoculars. It wasn't until
after the bird passed its apex that the variation in magnitude became
more pronounced. It seemed to blink on and off approximately ninety
times per minute.


Thanks for the confirmation! I was starting to think that my eyes were
playing tricks on me early that morning. This is a really interesting rocket to
track.

I'm assuming that the constant look to its brightness was because of it's
orientation. Maybe I was first seeing it at a nearly right angle to its axis of
rotation, and then when it was closer to the horizon I was seeing it more from
the side, tumbling end over end.

Paul Z
Indianapolis, IN

Thank you Paul and Bill for the reports! I would have seen
this one by now but for clouds every morning (moisture
streaming in from the Gulf of Mexico). I hope too see it
before too long, because over time it will slow down.
Okean O Rk (25861, 99-39B) started out the same way:

http://satobs.org/seesat/Jul-1999/0307.html

Paul, regarding your problem with SeeSat-L, have you contacted
the list administrator? There's an e-mail link in the first
paragraph of this page:

http://www.satobs.org/seesat/seesatindex.html

Ed Cannon - - Austin, Texas, USA
(Remove "donotspam".)

Thank you Paul and Bill for the reports! I would have seen
this one by now but for clouds every morning (moisture
streaming in from the Gulf of Mexico). I hope too see it
before too long, because over time it will slow down.
Okean O Rk (25861, 99-39B) started out the same way:

http://satobs.org/seesat/Jul-1999/0307.html

Paul, regarding your problem with SeeSat-L, have you contacted
the list administrator? There's an e-mail link in the first
paragraph of this page:

http://www.satobs.org/seesat/seesatindex.html

Ed Cannon - - Austin, Texas, USA
(Remove "donotspam".)

PZeller66 wrote:

Thanks for the confirmation! I was starting to think that my eyes were
playing tricks on me early that morning.

I had the same impression when I saw it, too.

I'm assuming that the constant look to its brightness was because of it's
orientation. Maybe I was first seeing it at a nearly right angle to its axis of
rotation, and then when it was closer to the horizon I was seeing it more from
the side, tumbling end over end.

That's my guess, too. It's the upper stage of a Russian Zenit-2
booster; astronautix.com describes that stage as being 3.9 meters
in diameter and 11.5 meters long, which allows a lot of change
in its observed area as it tumbles. My guess is that it did
something odd when it vented excess propellant after reaching
orbit.

I spotted it again less than an hour ago, in clear skies. The
flashing is still impressive.

--Bill Thompson