USA 103 - Optical Tracking Of HEO Centaur
From CANADIAN SPACE SOCIETY BBS (416)-458-5907
Organization: Johannes Kepler University Linz - Computing Center
Date: Fri, 6 May 1994 17:19:46 CDT
From: Herbert Raab
Newsgroups: sci.astro,sci.space
Subject: CCD Image of Barium Cloud
Lines: 38
A large, bright object, looking much like a comet, has been observed on
the evening of May 3, 1994, by many amateur astronomers across Europe.
When I first noticed it above the northwestern horizont around 19:45 UT, while
doing astrometric observations of minor planets together with two of my
friend, E.Meyer and E.Kolmhofer, it was located near Alogl (Beta Persei).
The location of our observing site is about 20km north of Linz, Austria.
With the naked eye, it was a bright, circular, diffuse cloud with an total
magnitude of about 0mag or 1mag. Through 7x50 binoculars, a stellar "nucleus"
was visible, with four jets pointing towards southeast and bending backwards
at some distance from the source. It looked much like the drawings of comet
"P/Swift-Tuttle" made during its appearence some 140 years ago.
While the hour angle did not change, the object moved northward by about
5 degrees per hour. For about an hour, the object remained very bright and
easiliy visible. Later, it faded constantly, and around 21:15 UT, only a faint,
diffuse cloud some 2 degrees in diameter was visible.
We contacted Mr.Marsden (Center for Astrophysics, Cambridge, USA), who in-
formed us that observers from Germany and France have also reported the
object, which probably was a Barium cloud released from some satellite.
If you know of any such experiment at that time, I would be glad to get some
more information|
I have posted a composite of three one-second-exposures made with an ST-6
CCD Camera on a Schmidt-Cassegrain Telescope of 288mm Diameter at an focal
length of 1500mm, as "CCD Image of Barium Cloud" on alt.binaries.pictures.
Each individual CCD image covers about 15'x20'. The central "point source"
and the bright jet towards the southeast are clearly visible. The image of
the "point source" was taken on 1994 05 03.83425 UT, with the 6,4mag (un-
filtered CCD magnitude) "point source" at R.A. = 03h 06m 18sec
Decl = +45d 43.7' (2000.0)
Greetings
Herbert
Newsgroups: sci.astro,sci.space
From: thomsona@netcom.com (Allen Thomson)
Subject: Re: CCD Image of Barium Cloud
Date: Sat, 7 May 1994 00:04:22 GMT
Lines: 8
Satellite watchers think that the diffuse object seen in Europe may
be venting from the Centaur upper stage of the Titan IV carrying a
classified satellite launched from Florida this week. The high inclination
of the launch leads to the speculation that the payload and upper stage
may have been put into a Molniya-type orbit. Observers are trying to spot
either of the objects.
From: thomsona@netcom.com (Allen Thomson)
Newsgroups: sci.space
Subject: USA 103/Centaur (was: Barium Cloud)
Date: Sat, 7 May 1994 13:56:07 GMT
Lines: 115
This message from Joel Runes appeared on the Celestial BBS; in the
interests of timeliness, I'm reposting it here before receiving his
approval to do so.
Please respond directly to Joel as well as posting here if you have
any observations to contribute.
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Observers throughout Europe reported sighting a luminous object up to
30 arc-minutes in diameter and as bright as 2nd magnitude. The observations
took place after sunset May 3rd as early as 2022 UTC and until at least
2200 UTC. Several of the observations were reported to Brian Marsden at the
Harvard-Smithsonian Center for Astrophysics. After determining that the
object was not a comet, the observations were handed off for determination
of possible earth-orbiting phenomena.
Analysis of the data suggest that the object is most likely to be a cloud
of vented residual propellants from a Centaur upper stage. A Titan IV-Centaur
was launched from Launch Complex 41 at Canaveral Air Force Station at 1555 UTC
on the 3rd. Press releases and other reports claim that the launch was into an
initial 57 degree inclination, that the Titan stages were in suborbital
trajectories impacting off the east coast of North America, and that a burn of
the Centaur stage placed the classified payload, USA 103, and Centaur into a
parking orbit.
Speculation as to the final orbit for the payload centered on the prospect
of being boosted into an elliptical Molniya-type orbit with perigee in the far
Southern Hemisphere to provide prolonged observations of the Northern
Hemisphere. Because systems of the Centaur stage are battery-powered, the
second Centaur maneuver was anticipated within several orbits after launch.
The European observations indicate that a Centaur maneuver occurred about
an hour after launch over the Southern Ocean boosting the orbit's apogee to
approx. 40,000 km. Either as a part of the apogee-raising maneuver or as a
separate maneuver 2 - 3 hours after launch, the inclination was changed from
57 degrees to more than 62 degrees, and the RAAN moved eastward by 8 - 10
degrees. Following the final maneuver of the Centaur Stage and separation of
the payload, it is customary to vent residual propellants to prevent
generation of debris from combustion or explosion. The cloud of residual
propellants was the likely phenomenon observed.
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A preliminary "working orbit" for the Centaur Stage based on the
European observations is being released to facilitate efforts by observers
to find the stage and/or payload. This working orbit is far from perfect.
I will continue my efforts to better fit the orbit to the European
observations and urge others to try their hands at it. High quality
observations from a group of Italian astronomers headed by L. Bittesini
(made from Farra d'Isonzo) and from the Ondrejov Observatory in the Czech
Republic by Petr Pravec and R. Peresty are summarized below:
Here are some approximate positions from the Ondrejov Observatory,
Czech Republic (longitude 14.7837 deg east, rho cos/sin phi' =
0.64530, +0.76148)
"comet" 1994 05 03.8588 03 38 00 +49 10 2 T 557
"comet" 1994 05 03.8672 03 49 30 +50 32 557
"comet" 1994 05 03.8714 03 54 50 +50 53 557
"comet" 1994 05 03.8799 04 01 40 +51 28 557
Here are the UT, R.A. and Decl. (J2000.0) of the object,
as observed from Farra d'Isonzo, Italy (longitude 13.53 deg
east, rho cos phi' = 0.697, rho sin phi' = +0.715 (rho being
the geocentric distance in earth-equatorial radii and phi' the
geocentric latitude).
CCAF37 C1994 05 03.84928 03 23 25.77 +48 39 50.8 595
CCAF37 C1994 05 03.85325 03 28 25.50 +49 19 32.2 595
CCAF37 C1994 05 03.85869 03 35 18.26 +50 10 58.6 595
CCAF37 C1994 05 03.86275 03 40 26.67 +50 47 20.0 595
CCAF37 C1994 05 03.86735 03 46 16.41 +51 26 44.9 595
CCAF37 C1994 05 03.87228 03 52 32.65 +52 06 56.2 595
CCAF37 C1994 05 03.87641 03 57 50.46 +52 38 50.4 595
Additional observation reports:
Approx positions:
03 40 +50 (1950) 20:30
Frauenstein
04 10 +50 (1950) 20:55 Luebeck
04 30 +54 (1950) 21:25 Luebeck
03 57 +50.75 (1950) 20:53 from site 10.65deg E, 52 deg 7 N
22:00 Object faded
The working orbit:
USA 103 Centaur 9.1 3.0 0.0 5.0 39736 x 618
1 23098E 94026B 94123.70803633 .00003650 00000-0 33989-3 0 15
2 23098 62.3466 8.4497 7365366 268.3594 359.9956 2.00624612 27
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Anyone with improved elements consistent with these observations is
requested to distribute them promptly and widely since the prospects of
observing USA 103 and/or the Centaur Stage will diminish rapidly. Reports
of observations of either object are also solicited.
Joel Runes
71177.3700@compuserve.com