Hi all!
This is my first post here. I'm looking for satellite observational
site/forum after having noted an unknown trail on my astronomical photo with
CCD camera.
Yes, my main interest is astro-imaging. I'm an amateur astronomer living in
L'Aquila, a small town close to centre of Italy. I consider satellite
observation a fascinating activity too. Moreover, sometimes activities
"crossing" are inevitable! Just like what is happened a few days ago.
Following a CCD camera recent purchase, I begin a survey principally for
test the new equipment, a Starlight Xpress SXV-H9 CCD camera (a very
sensitive camera) with a Pentax astrograph (500 mm focal lenght).
I find a mysterious trail on two photos of the Great Nebula of Orion (code
Messier 42). Both trails direction are on the same alignment, therefore it
seems that the object show a change of position between first and the second
shot. This is the reason to exclude cosmic rays cause (CCD cameras are very
sensitive to cosmic rays, resulting in a trail when they strike the CCD
image sensor at glancing angles).
A peculiarity is the relative low angular speed. I find approx 7'/minute
(about 1/8 of degree per minute). Then the unknown object is too slow
compared to an usual satellite (low orbit type) or an airplane, too fast
compared to an asteroid or a so faint comet.
Another important observation: on the basis of simple geometric
calculations, I find the object had to be at least 15000 Km from earth
surface so that it's outside earth shadow and the sun can light up it. In
fact the observation time was at about 00:45 local time (unusual moment for
common visual satellite) and the object was at about 40 degree above horizon
toward south azimuth.
Then, what is the object? I think about high altitude satellite in highly
eccentric orbits or geosynchronous transfer orbits (GTO) or mid earth orbit,
etc.
Furthermore I read about several satellite launch on 21 december, the same
day of my observations. Here is a list:
COSPAR/WWAS USSTRATCOM SPACECRAFT LAUNCH
INT.ID CAT. # NAME DATE (UT)
----------------------------------------------------------------
2005-049B 28912 MSG 2 21 December 2005
2005-049A 28911 INSAT 4A 21 December 2005
2005-048B 28909 Rodnik 21 December 2005
2005-048A 28908 Gonets-D1M 1 21 December 2005
2005-047A 28906 Progress-M 55 21 December 2005
May be a Rocket in transfer orbit?
I submit this questions to you, I think this is the best place to find an
answer! Meanwhile I request an account at Space-Track to retrieve global TLE
for simulations.
Follow all related observational informations:
Site coordinate
City: L'Aquila, Italy
Long.: 13° 24' 24" EAST
Lat.: 42° 20' 05" NORTH
Altitude: 700 meters over sea level
Photo #2 (complete trail)
Date: 21 december 2005
Time: U.T. from 23h:45m:46s to 23h:47m:46s (precision +/- 3 sec)
Total exposure time: 120 sec
Photo #1 (incomplete trail)
Date: 21 december 2005
Time: U.T. from 23h:43m:38s to 23h:44m:38s (precision +/- 3 sec)
Total exposure time: 60 sec
I find equatorial and azimutal coordinates (RA, Dec, Alt, Azim) for a
specific moment, thanks to the trail crossing over a note star. Star is
named SAO 132323 (visual star of apparent magnitude 2.75):
Right Ascension (RA2000): 5h 35m 26s
Declination (Dec2000): -5° 54' 36"
Crossing time: U.T. 23h:46m:30s
Alt. at crossing time: + 39°
Azim. at crossing time: 200°
I don't know the object apparent magnitude, but the CCD sensor is very
sensitive, then certainly it's not a very bright satellite.
This is the link to my photos, so you can estimate brightness and other
feature of the trail:
http://www.acvaquila.it/app/sat_track_aq.jpg
I Hope this is not an off-topic argument and you find it to be to your
liking. Waiting for good news!
Best regards and clear sky!
Paolo
PS: sorry for bad english...
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