49P/Arend-Rigaux

Comet 49P/Arend-Rigaux

2012 Jan 21

Mouse-over to browse the entire image without the specially-processed appendix in the upper left.

MPC observation computed with Astrometrica using both UCAC-3 and CMC-14 star catalogs -- the former for astrometric reduction and the latter for photometric work:

COD C42
CON M.-T. Hui, Dept. of Physics, Wuhan University, China
OBS M.-T. Hui, X.Gao
MEA M.-T. Hui
TEL 0.107-m f/2.8 refractor + CCD
NET UCAC-3
0049P        KC2012 01 21.82552 12 25 55.15 +16 10 52.0          16.0 N      C42
0049P        KC2012 01 21.83816 12 25 55.60 +16 11 04.7          15.9 N      C42
0049P        KC2012 01 21.85044 12 25 56.00 +16 11 17.5          16.1 N      C42
0049P        KC2012 01 21.86257 12 25 56.24 +16 11 32.3          16.2 N      C42
0049P        KC2012 01 21.87479 12 25 57.17 +16 11 41.5          16.1 N      C42
0049P        KC2012 01 21.88699 12 25 57.63 +16 11 57.3          16.0 N      C42
0049P        KC2012 01 21.89922 12 25 58.11 +16 12 08.0          16.0 N      C42
0049P        KC2012 01 21.91145 12 25 58.76 +16 12 18.9          15.8 N      C42
----- end -----

Photometry result computed with FOCAS II, which processes images based upon the .LOG file of Astrometrica, by means of Multibox method:

COD C42
CATALOG: USNO A2.0 / CMC-14 - BAND: R

                                   10x10 20x20 30x30 40x40 50x50 60x60 SNR SB COD
OBJECT        DATE       TIME        +/-    +/-    +/-    +/-    +/-    +/-     N FWHM CAT
------------ ---------- -------- ----- ----- ----- ----- ----- ----- ---- ---- ---
49P           21/01/2012 20:50:50 16.02 15.36 15.04 14.86 14.73 14.62 5.7 19.6 C42
49P           21/01/2012 20:50:50* 0.12 0.07 0.08 0.08 0.08 0.10     8 17.9 CMC

FoCAs II - 17/03/2010
www.astrosurf.com/cometas-obs
es.groups.yahoo.com/group/Cometas_Obs

Interpretation of the FOCAS II table headings:

Fisrt line:

OBJECT, DATE, TIME: refering to their original meanings respectively

10x10, 20x20 ... 60x60: the aperture sizes of photometry in term of rectangle in arcsec that are used to measure an object's magnitude

SNR: the Signal-to-Noise Ratio for aperture photometry

SB: stars of faintest magnitude on the images used in data reduction with the used star catalog in Astrometrica, rather than the stars of faintest magnitude in the images

COD: MPC Code of the observatory

Second line:

+/-: precisions of measurement

N: the number of used images for measurement

FWHM: Full-Width-Half-Maximum of total PSF, relevant to degree of seeing

CAT: the used star catalog in Astrometrica

As the comet was overwhelmed with numerous galaxies in southern Coma Berenices, I specifically stacked the images with registration to stars rather than to the comet as a byproduct of the observation. In order to receive photons as many as possible, the stop was fully used, and consequently, the images of the stars were mostly imperfect.

Mouse-over the image to see the one with labels added. Note that only some bright galaxies were labeled as too huge the total number of the galaxies is. Click the above image to browse the one in full resolution.

Feel free to e-mail me with any doubts or questions.