2 Observations and reductions

The observations were performed with the 1.6-m telescope at the OPD on August 2, 2000, equipped with direct imaging camera #1 (details in http://www.lna.br/instrum/camara/camara.html) and CCD #106 ( $1024\times 1024$ square pixels, 24 $\mu$m each), with RON = 4.1e^- and gain = 5.0e^-/ADU.

The data were acquired with standard Johnson B, V and Cousins R, I filters. The details of the observations are given in Table 1. Photometric calibration was accomplished using standard stars from Landolt (1992). We have used the mean extinction coefficients for the OPD: 0 $.\!\!^{\rm m}$34, 0 $.\!\!^{\rm m}$19 and 0 $.\!\!^{\rm m}$14 in the B, V and R passbands, respectively. The I-band image was obtained under non-photometric conditions and so we have used it to determine the position of the galaxy nucleus only. Reduction of the raw CCD data has been made in the standard manner using the ESO-MIDAS package.

 

 

Table 1: Observation log for August 2, 2000.

Bandpass	Airmass	Exp.	Seeing	Sky
		(s)	('')	mag.
R	1.147	900	1.0	20.4
R	1.109	900	1.0	20.4
R	1.078	900	1.0	20.4
B	1.052	900	1.8	21.5
B	1.033	900	1.7	21.5
B	1.018	900	1.8	21.5
V	1.008	900	1.7	20.7
V	1.002	900	1.7	20.7
I	1.001	900	1.7	Clouds