=========REPORT === Session on quasar 3C454.3 - 2007.09.07========[UT times]=========

Site: OAPM Osservatorio Astronomico Provinciale Montarrenti, Siena - Italy
Lat. 43°13'57"N - Long. 11°11'02"E

Observers: G.Bonnoli, L.Bruschi, A.Bucci, S.Leonini, A.Marchini, F.Papini,
D.Scutumella, L.M. Tinjaca Ramirez

From: 2007.09.07 h 19.55 UT
To: 2007.09.07 h 23.45 UT

Time: sync via radio-controlled clock
PC-clock precision within 1 second

JD Time: UT GEOCENTRIC (with NO heliocentric correction)

Sky: clear; seeing 4-5/5;
Moon: absent (rises after 1.00 UT)

Conditions: see DatiMeteo-ComuneSiena.txt for meteo data

Map and Photometric data from Bell Observatory
(astro.wku.edu/observatory/3c454.3.html)
Obj1: 3C454.3 (RA 22h53m57.7s Dec +16°08'54.0")
Ref1 (A): B=16.85 V=15.86 R=15.32 I=14.80
Ref2 (B): B=15.87 V=15.21 R=14.73 I=14.31
Ref3 (C): B=15.18 V=14.43 R=13.98 I=13.51
Ref4 (D): B=14.94 V=13.85 R=13.22 I=12.63
Chk1 (E): B=17.10 V=15.76 R=14.92 I=14.26
Chk2 (F): B=16.06 V=15.21 R=14.83 I=-----
Chk3 (G): B=16.28 V=15.42 R=14.83 I=-----
Chk4 (C1):B=----- V=15.67 R=15.27 I=14.71

Coordinates of the field read on the telescope controller:
A.R. 22:54:00 - Dec 16.08.05

Filter: B, V, R, I - SCHULER
Telescope: Ritchey-Chretien 530mm - F 4600mm
CCD: Apogee AP47p, 1024x1024
field 9.95'x9.95' - pixel 0.58"x0.58"

Acquisition software: MaxImDL-CCD 4.51
Data reduction software: MaxImDL 4.56
- calibration: dark-frame subtraction and bias correction
- Photometry: aperture 6 pixels - gap 14 - annulus 6

Additional notes:
- all the images were taken in binning 2x2; the CCD was rotated 90° CW,
(North=right; East=up)
- at 20.30 we noticed in the images an alo due to the condensation of
humidity on the ccd-chip window; it changed continuosly, affecting the
focus and the intensity of the stars
- for this problem we decided to increase the ccd temperature
(setpoint from -20°C to -18°C)
- we tried to take images with B filter with exp.time of 6 and 10 minutes,
setting a 3x3 binning too; no star was visible so we decided to not take
B filtered images
- flat-field frames not taken for the presence of the changeable moisture
on the ccd-chip window
- at the end of the session we inspected the filter wheel and the ccd-chip
window: the B filter was very dirty and we saw some humidity moisture on
the ccd-chip window
- after calibration we saved the images with the proper orientation

--- Conclusions ---
Despite the problems mentioned above, it was possible to measure the
magnitude of the quasar 3C454.3 in V, R, I with sufficient precision.
We used the best images for photometry measurements:
V filter: 4 images x360s, R: 3 x360s, I: 3 x360s

Magnitude of 3C454.3 computed with MaxImDL photometry routine:
- V= 15.43 (JD 2454351.415975 - 2007.09.07 h 21.59)
- R= 15.04 (JD 2454351.391663 - 2007.09.07 h 21.24)
- I= 14.53 (JD 2454351.464159 - 2007.09.07 h 23.08)

==================END OF REPORT ===========================

Se volete invece vedere la curva di luce dell'ultimo mese o degli ultimi anni di questo quasar, eccovi i link:
http://users.utu.fi/kani/1m/3C_454.3_l.png (ultimo mese)
http://users.utu.fi/kani/1m/3C_454.3.html (storico)

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