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67P/Churyumov-Gerasimenko  by Bernhard Haeusler, Germany

2009-03-18 by Bernhard Haeusler, Maidbronn, Germany         image frozen on stars and comet        

10 x 1 min. exposure, 2009-03-18, UT 19:02 to 19:13, 12" SCT  f-7 + CCD ST10XME
13.34mag, coma: 1'00", tail: 2'05" in PA 242

MPC observation: computed with Astrometrica

OBS Bernhard Haeusler
TEL 0.30-m Schmidt-Cassegrain + CCD


0067P C2009 03 18.79350 02 45 07.19 +18 35 45.7 13.3 N B82
0067P C2009 03 18.79507 02 45 07.57 +18 35 47.8 13.3 N B82
0067P C2009 03 18.79663 02 45 08.00 +18 35 49.8 13.4 N B82

Gauss curve produced by Astrometrica. The total PSF is using the aperture circle of 10 x 10 pixel around the brightest pixel.
You see the Gauss curve right as the computed ideal line and the real pixels contributed around the ideal line.
The Fit RMS is the deviation from the ideal line (inlay under the Gauss curve).

Photometry computed with FOCAS II, using the Multibox method:

OBS Bernhard Haeusler

                                                      10x10  20x20  30x30  40x40  50x50  60x60   SNR   SB  COD
OBJECT        DATE       TIME       +/-       +/-       +/-       +/-       +/-      +/-  N  FWHM  CAT
------------  ---------- --------  -----  -----  -----  -----  -----  -----  ----  ----  ---

67P               18/03/2009 19:04:53 13.34 12.59 12.26 12.06 11.92 11.81 27.3 17.8 B82
67P               18/03/2009 19:04:53* 0.01 0.01 0.01 0.01 0.00 0.01 5 4.9 CMC

FoCAs II - 07/01/2009-b

FOCAS II is a tool for photometry on the base of data coming from Astrometrica. Focas is basically using the .LOG file of Astrometrica.

Explanation of the FOCAS II table headings:

Object, date and time are self-explaining.
10x10, 20x20 ... 60x60 are the measured magnitudes according to the aperture sizes of photometry in arc sec (rectancle).
SNR is the  Signal-to-noise ratio for aperture photometry (calculator).
SB is the magnitude of the faintest star on the image matching with the used star catalogue. This is not the faintest star of the image!
COD is the MPC Code of the observatory.

second line:
+/- are the precisions of the measurements.
N is the number of the used images for the measurements.
FWHM is the Full-Width Half-Maximum of the total PSF: Measure of the seeing.
CAT is the used star catalog in Astrometrica.

Focas II is using the .log file of Astrometrica and is computing the photometry under different apertures (10x10 ... 60x60).
The graphs are showing the astrometric precision of the images.

The comet is moving towards its Aphel in March 2012 in a Sun distance of 5.67 AU.
March 2009 the distance to the Sun is only 1.29 AU
The European Spacecraft Rosetta will reach the comet in May 2014. A landing on the comet also planned.


http://astrosurf.com/cometas-obs/index_i.htm Visual and CCD Observations and images from the "Cometas Obs" mailing list, using the Focas II format

es.groups.yahoo.com/group/Cometas_Obs The Spanish comet observation group in Yahoo


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Copyright of all sites and images of this web: Bernhard Haeusler, Dettelbach, Germany   IAU code: B82 Maidbronn and K87 Dettelbach Vineyard Observatory