UBVRI field comparison stars for selected active quasars and BL Lacertae objects

Smith, Paul S.; Balonek, T. J.; Heckert, P. A.; Elston, R.; Schmidt, Gary D.

doi:10.1086/113824

Cited by 132 publications

(141 citation statements)

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“…In this work, for S5 0716+714, the VR comparison stars are from Villata et al (1998) and the I comparison stars are from Ghisellini et al (1997), and for 3C 273, the comparison stars are from Smith et al (1985). All the comparison stars have been listed in Table 1, in which, Col. 1 is signed label of comparison stars, Col. 2 is comparison stars at V band, Col. 3 is comparison stars at R band, and Col. 4 is comparison stars at I band.…”

Section: Observations and Data Reductionsmentioning

confidence: 99%

Optical monitoring of BL Lac object S5 0716+714 and FSRQ 3C 273 from 2000 to 2014

Yuan

Fan

Tao

et al. 2017

A&A

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Context. Using the 1.56 m telescope at the Shanghai Observatory (ShAO), China, we monitored two sources, BL Lac object S5 0716+714 and flat spectrum radio quasar (FSRQ) 3C 273. For S5 0716+714, we report 4969 sets of CCD (Charge-coupled Device) photometrical optical observations (1369 for V band, 1861 for R band and 1739 for I band) in the monitoring time from Results. The two sources both show IDV properties for S5 0716+714. The timescales are in the range from 17.3 min to 4.82 h; for 3C 273, the timescale is ∆T = 35.6 min. Based on the periodic analysis methods, we find the periods P V = 24.24 ± 1.09 days, P R = 24.12 ± 0.76 days, P I = 24.82 ± 0.73 days for S5 0716+714, and P = 12.99 ± 0.72, 21.76 ± 1.45 yr for 3C 273. The two sources displayed the "bluer-when-brighter" spectral evolution properties. Conclusions. S5 0716+714 and 3C 273 are frequently studied objects. The violent optical variability and IDV may come from the jet. Gaussian fitting can be used to analyze IDVs. The relations between brightness (flux density) and spectrum are strongly influenced by the frequency.

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Section: Observations and Data Reductionsmentioning

confidence: 99%

Optical monitoring of BL Lac object S5 0716+714 and FSRQ 3C 273 from 2000 to 2014

Yuan

Fan

Tao

et al. 2017

A&A

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“…No dark frame was needed since the CCD camera was cooled sufficiently. Instrumental magnitudes of BL Lac and comparison stars B and C from Smith et al (1985) were extracted using an auto photometry package (AUTOPHOT), which was developed to minimize the repetition. Subsequently, the instrumental magnitudes were converted to apparent magnitudes through differential photometry.…”

Section: Observations and Data Reductionmentioning

confidence: 99%

Intra-night optical multiband variability of BL Lacertae during the 2011 outburst

Zhai

Wei

2012

A&A

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Aims. We present our optical multiband (B and R) observations of BL Lacertae, which were acquired over 20 nights from May 26 to August 3, 2011, and analyse our data to study the optical emission variability properties of BL Lac. Methods. The simultaneous photometric observations were carried out using the 0.8 m Tsinghua-NAOC Telescope (TNT) at the Xinglong Observatory of National Astronomical Observatories, Chinese Academy of Sciences (NAOC). TNT is equipped with the Princeton Instrument CCD and standard Johnson-Cousin UBVRI filters. Exposure times were well chosen to make a good compromise between high precision and high temporal density. Results. A multipeak outburst was observed in 2011 observing season. The brightest magnitudes for BL Lac during our observations were B = 14.48 mag and R = 12.89 mag at JD = 2 455 709.2810 (May 27). One of the most rapid variations was detected on July 9, when a flux increase of about 0.34 mag occurred over 2.8 h. In general, both the amplitude of variability and the variation rate are higher at the shorter wavelength. A colour analysis shows that the colour variability processes are apparently complicated. A bluerwhen-brighter trend was detected during the outburst. These trends may be the interactive contribution from a "mildly-chromatic" component and a "strongly-chromatic" one. Meanwhile, intra-night variability in B and R bands was found to be correlated, without any time delay exceeding 2.5 min.

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“…Smith et al 1992 and references therein) for all observations. The data acquisition and reduction follow the procedures employed in past projects with Two-Holer to calibrate comparison stars in the fields of quasars and both radio and X-ray-selected BL Lac objects (Smith et al 1985;Smith, Jannuzi, & Elston 1991). Between 10 and 30 equatorial photometric standards (Landolt 1983(Landolt , 1992 were observed each night to transform instrumental magnitudes to the standard UBVRI system.…”

Section: Observationsmentioning

confidence: 99%

Photometric Calibration of Stars in the Fields of Selected BL Lacertae Objects and Quasars

Smith¹,

Balonek²

1998

PUBL ASTRON SOC PAC

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ABSTRACT. We present the results of UBVRI photometry of stars in the fields of 13 BL Lacertae objects and quasars. The calibrated stars are intended to facilitate photoelectric and CCD differential photometry of these highly variable active galactic nuclei (AGNs). The magnitudes of most of the stars were measured on more than two occasions, and we provide two to five stars per field. Several stars are common to those calibrated by previous observers, although the earlier efforts do not cover all five bandpasses. Our results for these stars are typically in close agreement with previous measurements obtained using common filters. In addition, we present UBVRI magnitudes for stars in the fields of four AGNs (CTA 26, 0716ϩ332, OVϪ236, and PKS 2345Ϫ167) with no previously published comparison stars.

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UBVRI field comparison stars for selected active quasars and BL Lacertae objects

Cited by 132 publications

References 0 publications

Optical monitoring of BL Lac object S5 0716+714 and FSRQ 3C 273 from 2000 to 2014

Optical monitoring of BL Lac object S5 0716+714 and FSRQ 3C 273 from 2000 to 2014

Intra-night optical multiband variability of BL Lacertae during the 2011 outburst

Photometric Calibration of Stars in the Fields of Selected BL Lacertae Objects and Quasars

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