Автор Тема: Помогите определить точное время  (Прочитано 3806 раз)

Serj

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Помогите определить точное время
« : Февраль 09, 2011, 22:51:43 »
Парни, помогите! Наверняка для вас это не будет сложно. В общем, снимали наши французские друзья покрытие звезды астероидом Huya (извините за мой плохой французский ;D) и произошёл с ними epic fail. К счастью на одном из кадров есть что то похожее на спутник. Привожу письмо полностью:
Цитата: Huya and geostationary appulse at Pic du Midi this morning.
From J.Lecacheux

On Wed, 09 Feb 2011 10:01:16 +0100, frappa@euraster.net wrote:
Показать цитату
...
 Again perfect conditions but new clear negative result for
 the Huya event, observed on the 1m telescope with a Raptor
 Merlin camera (0.5s integration) from 5h05 to 6h20 UT.
...

Help !
We met some difficulties when setting up the precise datation
of our HUYA data acquisition this morning. It is based upon a
Garmin GPS18, but the string of characters corresponding to
the UTC was wrong at the beginning of our observation.
Fortunately, following some frenzied hardware resets, starting
from 5:02 UT our recorded time seemed have become correct.

There is high probability that the initial problem then had
disappeared, but a slight doubt can subsist. Any error at
5:02 UT would have persisted along our whole 79 mn record
of the Huya event.


Fortunately a geostationary satellite passed very close to
faint HUYA target at our recorded time 05:07:46.9 UTC.
***
Is somebody among the [planoccult] community able
1/ to identify this satellite,
and
2/ to check the accuracy of the above UTC ?

***

The attached image i647.jpg is a JPEG version of our 647th
half-second exposure.

Remark: The original images are in Fits format. The JPEG
compression here is needed in reason of the size limit of
[planoccult] messages.

North is up, East at the left.
The bright trailed satellite (7.5 arc sec. East-West trail)
is just above the image centre.

The tiny star just above the satellite is the HUYA target,
V ~ 15.8, R ~ 15.4  (the extra flux from Huya being
negligible).

A fainter star (V ~ 16.7 , R ~ 16.4) lies 15.5 arc sec. WSW
from the HUYA target. Another fainter neighbour star (V ~ 17.1,
R ~ 16.9) lies 43 arc sec. south from the Huya target, below
the satellite trail, but here is almost erased by the JPEG
compression.

Remark : The distorted star images at the FOV periphery are due
partly to chromatic aberration (as no filter was used), partly
to excessive focal reduction (about 0.21 instead of the nominal
0.30 of the used focal reducer).


Recall :
Huya target (UCAC2): J2000: 15h 14m 59s.328  -04o 35' 13".62
Pic-du-Midi (WGS84):       E00o 08' 32".5 E  N42o 56' 10".9  2870m

Estimated satellite position at 05:07:46.9 UTC :
                     J2000: 15h 14m 59s.33   -04o 35' 32".3

Temperature: -3 deg. C   Pressure : 718 HPa    Humidity : 22 %


Thank you in advance.
Скажите, можно ли определить точное время этого снимка? Координаты обсерватории 42°56′N 0°8′E / 42.933°N 0.133°E, точнее пока сказать немогу.

Serj

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Re: Помогите определить точное время
« Ответ #1 : Февраль 09, 2011, 23:11:46 »
Кажется уже идентифицировали:
Цитата: Jan Manek
Hello Jean,

according to my finding the satellite is Intelsat 6-3. Attached is image showing the satellite just 3 seconds before the reported time, together with track for next 6 seconds. It can be seen the appulse occured few tenths of second prior to 5:07:47 UT. I think this is in a good agreement with your image and basically confirmation of your timing.

Best regards, jan

Intelsat 6-3
Period of orbit      1436.08 minutes
   Epoch of elements   JD 2455600.71241253 ( 8 Feb 2011  5:05:52)
Perigee 35784.3 km
Apogee 35790.2 km
Elements, in TLE form:
1 20523U 90021A   11039.21241253  .00000076  00000-0  00000+0 0  7695
2 20523 007.8025 060.1457 0000702 270.0438 255.6972 01.00273015 69507
Breakdown of data from the TLE:
  NORAD designation: 20523
  International designation: 1990-021A
  Elements are unclassified
  Epoch of elements,  NORAD-style (year & day of year): 2011 039.2124125
  Rate of change of mean motion,  revolutions/(day*day): .00000076
  BSTAR drag term:  .00000E+0
  Bulletin number: 769
  Inclination of orbit: 007.8025
  Right ascension of ascending node: 060.1457
  Eccentricity: 0.0000702
  Argument of perigee: 270.0438
  Mean anomaly: 255.6972
  Mean motion: 01.00273015 revolutions/day
  Revolution number: 6950