c2007n3_20090317

C/2007 N3 (Lulin)

C/2007 N3 (Lulin) � by Bernhard H�usler, Germany

� 2009-03-17 by Bernhard Haeusler, Maidbronn, Germany Original size

20 min. exposure, 2009-03-17 UT 21:12, 12" SCT f-7 + CCD ST10XME
image size: 24' x 16', North up, East left

MPC observation: computed with Astrometrica

COD B82
OBS Bernhard Haeusler
MEA Bernhard Haeusler
TEL 0.30-m Schmidt-Cassegrain + CCD

NET CMC-14

CK07N030 C2009 03 17.88478 07 17 37.39 +21 32 32.1 12.2 N B82
CK07N030 C2009 03 17.88557 07 17 37.18 +21 32 32.3 12.2 N B82
CK07N030 C2009 03 17.88715 07 17 36.82 +21 32 33.1 12.2 N B82
CK07N030 C2009 03 17.88795 07 17 36.64 +21 32 33.2 12.2 N B82

Gauss curve produced by Astrometrica. The total PSF is using the aperture circle of 20 x 20 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:

COD B82
OBS Bernhard Haeusler
CATALOG: USNO A2.0 /BAND: CLEAR

                                                      10x10 20x20 30x30 40x40 50x50 60x60   SNR   SB COD
OBJECT        DATE       TIME       +/-      +/-     +/-     +/-      +/-     +/-  N FWHM CAT
------------ ---------- -------- ----- ----- ----- ----- ----- ----- ---- ---- ---
C/2007 N3    17/03/2009 21:16:21 12.23 11.35 10.88 10.57 10.33 10.13 58.9 19.1 B82
C/2007 N3   17/03/2009 21:16:21* 0.00 0.01 0.01 0.01 0.01 0.01 5 4.5 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.

Facas 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.

links:

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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