J/ApJS/281/44 NGT optical monitoring of the blazar OJ 287 (Yuan+, 2025)
Optical monitoring and spectral analysis of OJ 287.
Yuan Y.-H., Chen Q.-M., Liu Y.-T., Liang B.-Y., Yang W.-X., Ou L.-J.,
Chen G.-H.
<Astrophys. J. Suppl. Ser., 281, 44 (2025)>
=2025ApJS..281...44Y 2025ApJS..281...44Y
ADC_Keywords: Active gal. nuclei; BL Lac objects; Photometry; Optical
Keywords: Blazars ; CCD photometry ; Active galaxies
Abstract:
We present a comprehensive multiband optical monitoring and spectral
analysis of the blazar OJ 287, conducted using the 1.26m National
Astronomical Observatory-Guangzhou University Infrared/Optical
telescope (NGT). During an intensive 17 day observational campaign
from 2022 December to 2023 January, we obtained 2716 high-quality
photometric observations (929 in the g band, 887 in the r band, and
900 in the i band). The data reveal significant variability across all
bands. Our main findings are as follows. (1) Significant magnitude
variations were detected: Δmg=0.945±0.048mag (g band),
Δmr=0.648±0.023mag (r band), and
Δmi=0.945±0.051mag (i band). (2) Numerous intraday
variability (IDV) events were identified, with characteristic
parameters (Δm, ΔT, and VR=Δm/ΔT) showing
consistent patterns between the g and r bands but distinct behavior in
the i band. (3) Successful modeling of intraday light curves using a
multi-Gaussian function, yielding brightening (ΔTb') and
dimming (ΔTd') timescales, and revealing an average peak
separation of ΔTc=42.96±0.99 minutes that appears to be
frequency independent. (4) Development of a novel radiation framework
suggesting that the observed IDV phenomena originate from multiple
components-with the frequency-independent variations attributable to
the central black hole, while frequency-dependent variations stem from
jet and accretion disk processes.
Description:
The 1.26m National Astronomical Observatory-Guangzhou University
Infrared/Optical telescope (NGT) is located at Xinglong station,
National Astronomical Observatories, Chinese Academy of Sciences.
Our monitoring duration is from 2022 December 4 to 2023 January 28,
and contains 2716 observations at the g, r, and i bands.
Objects:
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RA (ICRS) DE Designation(s)
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08 54 48.87 +20 06 30.6 OJ 287 = OHIO J 287
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 59 929 NGT g, r, and i band observations of OJ 287
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See also:
J/A+AS/116/403 : VRI photometry of stars in 12 BL Lac objects (Fiorucci+, 1996)
J/A+A/450/39 : BVRI photometry of 8 red blazars (Gu+, 2006)
J/AJ/132/1256 : BATC e, i and m photometry of OJ 287 (Wu+, 2006)
J/ApJ/716/30 : SED of Fermi bright blazars (Abdo+, 2010)
J/A+A/559/A20 : Historical outbursts of OJ287 (Hudec+, 2013)
J/ApJS/213/26 : Optical light curves of PHL1811 and 3C273 (Fan+, 2014)
J/ApJS/226/20 : X-ray, opt. & radio SEDs of Fermi blazars (Fan+, 2016)
J/ApJ/837/45 : 2006-2012 Rc-band & 4.8GHz obs. of AO 0235+164 (Fan+, 2017)
J/ApJS/229/21 : VRI monitoring of the QSO 3C 273 in 2005-2016 (Xiong+, 2017)
J/AJ/157/95 : Optical variability of OJ 287 in 2016-2017 (Gupta+, 2019)
J/ApJS/269/60 : Optical monitoring from 2020-2022 of BL Lac (Yuan+, 2023)
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 6 F6.3 d JDg [17.86/72.93] Julian Date in g-band, JDg-2459900
8- 13 F6.3 mag gmag [15.36/16.32] Apparent g-band magnitude
15- 19 F5.3 mag e_gmag [0.007/0.05] Uncertainty in gmag
21- 26 F6.3 d JDr [17.86/72.96]? Julian Date in r-band, JDr-2459900
28- 33 F6.3 mag rmag [14.78/15.44]? Apparent r-band magnitude
35- 39 F5.3 mag e_rmag [0.008/0.02]? Uncertainty in rmag
41- 46 F6.3 d JDi [17.86/72.98]? Julian Date in i-band, JDi-2459900
48- 53 F6.3 mag imag [13.98/14.94]? Apparent i-band magnitude
55- 59 F5.3 mag e_imag [0.015/0.045]? Uncertainty in imag
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History:
From electronic version of the journal
License: CC-BY-4.0
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 29-Jun-2026