Optical Photometry of the Quasar 3C 454.3 during the Period 2006–2018 and the Long-term Periodicity Analysis

2021 ◽  
Vol 253 (1) ◽  
pp. 10
Author(s):  
J. H. Fan ◽  
S. O. Kurtanidze ◽  
Y. Liu ◽  
O. M. Kurtanidze ◽  
M. G. Nikolashvili ◽  
...  
Keyword(s):  
Optical Photometry ◽  
Periodicity Analysis

Long-term optical photometry of the dwarf nova VW Hyi

1987 ◽  
Vol 130 (1-2) ◽  
pp. 127-134
Author(s):  
S. F. Van Amerongen ◽  
J. Van Paradijs
Keyword(s):  
Optical Photometry ◽  
Dwarf Nova

Long Term Periodicity Analysis of OJ 287 at Optical V Waveband

2014 ◽  
Vol 35 (3) ◽  
pp. 301-305 ◽  
Author(s):  
Jie Tang ◽  
Hao-Jing Zhang ◽  
Qiao Pang
Keyword(s):  
Periodicity Analysis

scholarly journals Long-Term Optical Photometry of the Dwarf Nova VW Hyi

1987 ◽  
Vol 93 ◽  
pp. 127-134
Author(s):  
S.F. Van Amerongen ◽  
J. Van Paradijs
Keyword(s):  
Secular Change ◽  
Optical Photometry ◽  
Dwarf Nova ◽  
Upper Limits

AbstractLong-term five-colour photometry of the dwarf nova VW Hyi shows no evidence for a secular change of the flux during the quiescent interval between normal outbursts (3σ upper limits between 0.16 and 0.20 mag in the five passbands). However, the amplitudes in the orbital B-U and U-W colour curves change during quiescence. A delay in the progress of normal outbursts toward higher frequencies confirms the delay, seen with IUE, in the onset of a normal outburst toward higher frequencies. Just after outburst, the system is substantially bluer than later in quiescence.

scholarly journals Long-Term Optical Behavior of BL Lac Objects

1994 ◽  
Vol 159 ◽  
pp. 394-394
Author(s):  
S. Kikuchi
Keyword(s):  
Time Scale ◽  
Shock Model ◽  
Bl Lac Objects ◽  
Optical Photometry ◽  
Preferred Direction ◽  
Bl Lac ◽  
Direction Of Polarization ◽  
Optical Behavior

On the basis of results of optical photometry and polarimetry of OJ287 and Mrk421 since 1981, we find two states of activities for both objects. In OJ287, a color-magnitude relation which is consistent with the standard jet-shock model is seen after the outburst in 1983, while before 1982 the optical colors were almost constant. In Mrk421, the colors became redder in 1985–87, and the change of the preferred direction of polarization was associated on smaller time scale in 1987.

scholarly journals Optical variability of PHL 1811 and 3C 273

2014 ◽  
Vol 10 (S313) ◽  
pp. 79-80
Author(s):  
J. H. Fan ◽  
O. Kurtanidze ◽  
Y. Liu ◽  
Y. H. Yuan ◽  
J. M. Hao ◽  
...  
Keyword(s):  
Time Scale ◽  
Optical Variability ◽  
Optical Photometry ◽  
Analysis Methods ◽  
Periodicity Analysis

AbstractIn this work, we reported the optical photometry monitoring results for two brightest nearby quasars, PHL 1811 and 3C 273 using the ST-6 camera at Abastumani Observatory, Georgia. For PHL 1811, we found 3 microvariability events with time scale of ΔT = 6.0 min. For 3C273, we found that the largest variations are ΔV = 0.369 ± 0.028 mag, ΔR = 0.495 ± 0.076 mag, and ΔI = 0.355 ± 0.009 mag. When periodicity analysis methods are adopted to the available data, a period of p = 5.80 ± 1.12 years is obtained for PHL 1811, and p = 21.10 ± 0.14, 10.00 ± 0.14, 7.30 ± 0.09, 13.20 ± 0.09, 2.10 ± 0.06, and 0.68 ± 0.05 years are obtained for 3C 273.

scholarly journals Long-term and intra-day variability of BL Lacertae since the last great outburst

2006 ◽  
Vol 2 (S238) ◽  
pp. 419-420 ◽  
Author(s):  
Maria G. Nikolashvili ◽  
Omar M. Kurtanidze
Keyword(s):  
Ccd Camera ◽  
Active Phase ◽  
Optical Variability ◽  
Optical Photometry ◽  
Bl Lacertae ◽  
Maximum Variation

AbstractWe present the results of optical photometry of BL Lacertae carried out using ST-6 CCD camera attached to the Newtonian focus of the 70 cm meniscus telescope of Abastumani Observatory. On the basis of observations conducted since August 1997 during more than 550 nights about 17000 frames were collected. They have been reduced using Daophot II.It has been shown that optical variability of BL Lacertae is very complex. The maximum variation was observed at long-term scale and is equal to equals to 3.0 mag (rms=0.03) in B band, while the variation in V and R bands are within 2.71 mag (0.02) and 2.53 mag (0.01), respectively. This means that variations are larger at shorter wavelength or the object become bluer in the active phase. It were also demonstrated that BL Lacertae shows intra-day variability within 0.30 mag (0.02), while intra-hour variability within 0.10 mag (0.01) magnitudes.

Sign in / Sign up

Export Citation Format

Share Document