J/A+A/395/11 BV(RI)c photometry of ON 231 during outburst (Tosti+, 2002)
The optical behaviour of ON 231 (W Comae) during and after the great outburst
of spring 1998.
Tosti G., Massaro E., Nesci R., Ciprini S., Nucciarelli G., Maesano M.,
Montagni F., Raiteri C.M., Villata M., Lanteri L., Ostorero L.
<Astron. Astrophys. 395, 11 (2002)>
=2002A&A...395...11T 2002A&A...395...11T
ADC_Keywords: BL Lac objects ; Photometry, UBVRI ; Photometry, Cousins
Keywords: galaxies: active - galaxies: individual: ON 231 - galaxies: photometry
Abstract:
We present the results of the optical monitoring of the BL Lac object
ON 231 from 1997 to the spring 2001, including the large outburst of
spring 1998. After this event the mean source luminosity declined
slowly and continued to show changes greater than one magnitude. A
simple analysis of the variability time scales in the best-sampled
segments of the light curve reveals that the luminosity changes were
faster during the burst and slowed down in the subsequent years.
Description:
The photometric data presented in this paper have been obtained in
the course of a monitoring program of a sample of bright blazars
carried out since 1994 by our collaboration. The telescopes used were
the AIT (0.40m) of the Perugia Observatory, the 1.05m astrometric
telescope of the Observatory of Torino, the TRC 70 (0.70m, f/8.3) of
the IAS-CNR and "La Sapienza" University, the reflector telescope
(0.50m, f/4.5) of the Astronomical Station of Vallinfreda near Rome
and another reflector (0.35m) located near Greve, in Tuscany. All the
instruments were equipped with CCD cameras and standard filters for
the Johnson B, V and Cousins R, I bandpasses.
Objects:
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RA (2000) DE Designation(s)
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12 21 31.7 +28 13 59 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 94 360 BVRI photometry, from March 1997 to June 2001
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See also:
J/A+A/356/L21 : BR photometry of ON 231 (Belokon+, 2000)
J/A+AS/130/109 : BV(RI)c photometry of ON 231 (Tosti+ 1998)
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 10 A10 "YYYY/MM/DD" Date UTC Date
12- 22 F11.3 d HJD Heliocentric Julian Date
25- 29 F5.2 mag Bmag ? B (Johnson) magnitude
33- 36 F4.2 mag e_Bmag ? B (Johnson) magnitude error
39- 43 F5.2 mag Vmag ? V (Johnson) magnitude
47- 50 F4.2 mag e_Vmag ? V (Johnson) magnitude error
53- 57 F5.2 mag Rcmag ? R (Cousins) magnitude
61- 64 F4.2 mag e_Rcmag ? R (Cousins) magnitude error
67- 71 F5.2 mag Icmag ? I (Cousins) magnitude
75- 78 F4.2 mag e_Icmag ? I (Cousins) magnitude error
81- 94 A14 --- Obs Origin of data (1)
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Note (1): Origin of data:
PG: Perugia Observatory
RM: Roma Observatories
TO: Torino Observatory
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Acknowledgements: Gino Tosti
(End) Patricia Bauer [CDS] 17-Mar-2003