NASA/IPAC EXTRAGALACTIC DATABASE
Date and Time of the Query: 2019-08-25 T07:55:06 PDT
Help | Comment | NED Home

For refcode 2009AJ....138.1428F:
Retrieve 1 NED object in this reference.
Please click here for ADS abstract

NED Abstract

Copyright by American Astronomical Society. Reproduced by permission
2009AJ....138.1428F Optical Observations of 3C 273 From 2000 to 2008 Fan, J. H.; Peng, Q. S.; Tao, J.; Qian, B. C.; Shen, Z. Q. Abstract. The quasar 3C 273 is one of the widely studied quasars that is also a selected target in our monitoring program. In this paper, we present the optical V, R, and I photometric observations done with the 1.56 m telescope at the Shanghai Astronomical Observatory from 2000 to 2008. Our monitoring results show 1118 sets of observations (258 sets for the V band, 414 sets for the R band, and 446 sets for the I band). The observations indicate that (1) the variations in the three bands are {DELTA}V = 1.363 +/- 0.088 mag from V = 12.204 +/- 0.062 to V = 13.567 +/- 0.062, {DELTA}R = 1.299 +/- 0.023 mag from R = 12.014 +/- 0.014 to R = 13.313 +/- 0.013, and {DELTA}I = 1.041 +/- 0.088 mag from I = 11.628 +/- 0.046 to I = 12.669 +/- 0.075. Compared with the result by Toone, who presented the yearly averaged light curve during the period of 1980-2004 and found that the source shows a slow brightening with <V> = 12.95 in 1996-1997 to <V> = 12.5 in 2003-2004, our observations show that it is variable and both a state brighter than the yearly averaged brightness of <V> = 12.5 and a state fainter than the yearly averaged brightness of <V> = 12.95 were detected in our observing period. Intra-day variation timescales are from 13 minutes to 245 minutes. (2) The color indices are variable with V-R from -0.27 to 0.68, V - I from 0.11 to 1.14, and R - I from 0.14 to 0.86. The average values are <V - R> = 0.18 +/- 0.10, <V - I> = 0.64 +/- 0.14, and <R - I> = 0.46 +/- 0.11. Key words: galaxies: active, galaxies: individual: 3C 273, galaxies: photometry
Retrieve 1 NED object in this reference.
Please click here for ADS abstract

Back to NED Home