Novità dell'ultimissimo minuto da un osservatorio professionale:
Telescope: 2.0-m Faulkes Telescope South (f/10.0 Ritchey-Chretien + CCD)
Observing window: 2010 Apr 16 12:02-12:27 UT
Total of 13 images made in 1.5 arcsec FWHM seeing using B,V,R,g',r',i' and Z filters
The PSF of object is slightly non-stellar in that, for example, the
brightest pixel of star of similar magnitude (R=12.7) = 15480 adu (fwhm = 1.5") whilst the brightest pixel of object (R=12.7) = 9641 adu (fwhm =
1.6").
Precise Sloan filter photometry relative to SDSSJ133859.27+044740.0
(r'=14.647, g'-r'=0.408) using 4.2 arcsec radius photometric apertures
yields the following:
NEOCP Object: 04F0011
2010 Apr 16 (UT)
12:14:20 r'=12.973
12:16:20 g'=13.469
12:19:30 i'=12.853
12:26:27 r'=12.959
Hence g'-r'=0.503 and r'-i'=0.113 and the r' magnitude may have brightened by 0.014 mag in 12.1 min. The absolute uncertainty i n the photometry is expected to be 0.015 mag, the relative uncertainty is expected to be less than 0.005 mag (SNR of comparison star >500).
Photometry using 4.2 arcsec apertures of three other R-filter images
indicate brightening of the object amounting to 0.012 mag in 18.6 min.
Astrometry has been reported to the Minor Planet Center.
No extended coma is visible in any image.
No obvious co-moving object is evident in the frames.
Conclude that this moving object is slightly non-stellar and at the epoch of the observations was brightening at a rate of 0.05 mag/hr.
Richard Miles
British Astronomical Association
