J/A+AS/130/109 BV(RI)c photometry of ON 231 (Tosti+ 1998)
BV(RI)c monitoring of ON 231 during the great outburst in 1994-1997
Tosti G., Fiorucci M., Luciani M., Rizzi M. Villata N.,
Raiteri C.M., De Francesco G., Lanteri L., Chiaberge M.,
Peila A., Cavallone M., Sobrito G., Maesano M., Massaro E.,
Montagni F., Nesci R., Ghisellini G., Takalo L.O., Sillanpaa A.,
Katajainen S., Heinamaki P., Nilsson K., Pursimo T.
<Astron. Astrophys. Suppl. Ser. 130, 109 (1998)>
=1998A&AS..130..109T 1998A&AS..130..109T (SIMBAD/NED BibCode)
ADC_Keywords: BL Lac objects ; Photometry, UBVRI ; Photometry, Cousins
Keywords: BL Lacertae objects: general ; individual: ON 231
Abstract:
We present the most continuous data base of optical multiband data
ever published on the BL Lacertae object ON 231 (W Com). The data have
been collected during an intensive and coordinated BV(RI)c
monitoring campaign carried out in the period from March 1994 to March
1997. During our campaign, the source brightness was at the highest
level ever observed. The light curve shows a complex structure,
characterized by the presence of three major outbursts having the
observed maxima in March 1995, February 1996, and January 1997, when
ON 231 reached its historical maximum (B~=14.2). Variability on time
scales from a few hours up to a month have frequently been observed
and the light curve seems to be the superposition of many flares with
different amplitudes and time scales. The broad-band optical spectral
energy distribution is characterized by a spectral slope which
correlates with the flux level. In particular, the higher is the flux
the flatter is the spectrum.
Objects:
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RA (2000) DE Designation(s)
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12 21 27.5 +28 14 00 ON 231 = W Com = OHIO N 231
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 80 332 List of BVRI data
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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/395/11 : BV(RI)c photometry of ON 231 during outburst (Tosti+, 2002)
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 11 F11.3 d HJD Heliocentric Julian Day
13- 17 F5.2 mag Bmag ? B (Johnson) magnitude and standard deviation
20- 23 F4.2 mag e_Bmag ? rms uncertainty on Bmag
25- 29 F5.2 mag Vmag ? V (Johnson) magnitude and standard deviation
32- 35 F4.2 mag e_Vmag ? rms uncertainty on Vmag
37- 41 F5.2 mag Rmag ? R (Cousins) magnitude and standard deviation
44- 47 F4.2 mag e_Rmag ? rms uncertainty on Rmag
49- 53 F5.2 mag Imag ? I (Cousins) magnitude and standard deviation
56- 59 F4.2 mag e_Imag ? rms uncertainty on Imag
61- 70 A10 ---- Obs Observatory (1)
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Note (1): PG = Perugia
RM = Roma
TO = Torino
TU = Tuorla
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Acknowledgements: Gino Tosti
(End) Patricia Bauer [CDS] 01-Dec-1997