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J/A+AS/116/1        UBV photometry of MWC560 (Tomov+, 1996)
Monitoring MWC560=V694 Mon in 1990-1995. I.
Conventional and high-speed UBV photometry
     Tomov T., Kolev D., Ivanov M., Antov A., Jones A., Mikolajewski M.,
     Lepardo A., Passuello R., Saccavino S., Sostero G., Valentinuzzi T.,
     Bellas-Velidis Y., Dapergolas A., Munari U.
    <Astron. Astrophys. Suppl. Ser. 116, 1 (1996)>
    =1996A&AS..116....1T      (SIMBAD/NED BibCode)
ADC_Keywords: Photometry, UBV ; Stars, variable

Keywords: stars: binaries: close - stars: binaries: symbiotic -
          stars: individual: MWC560 - stars: magnetic fields -
          stars: mass-loss

Description:
    We present results of an extensive photometric monitoring campaign of
    the peculiar emission star MWC 560 that covers the range 1990-1995.
    The time interval corresponds to the length of the proposed orbital
    period of this highly peculiar binary, which attracted considerable
    interest in January-April 1990, when absorption components, shifted by
    -6000km/s from corresponding emission lines, were observed. Here we
    present photometric data secured during: 113 nights of conventional
    UBV photoelectric photometry, 45 nights of high speed UBV
    photoelectric photometry to study the flickering activity, and 682
    visual photometric estimates. MWC 560 has experienced a decrease in
    magnitude since the bright (V=9.2mag) phase in 1990. After the minimum
    reached in May 1994 (V=10.7mag), the star is currently increasing
    slowly in brightness. The decrease has been accompanied in all bands
    by large fluctuations superimposed on the mean trend. The B-V
    colour has shown a steady increase by 0.0.33mag/yr. U-B has remained
    stable at -0.07mag since late 1990. In all the observing nights
    devoted to high speed photometry we observed flickering activity in
    MWC 560. The data show that the flickering amplitude {DELTA}U
    increases with the decrease of the U magnitude. Quasi-periodic
    variations have always been detected. A period of ∼70min has been
    observed in ∼13 nights which is close to the ∼60min quasi-period
    reported by Michalitsianos et al. (1993). However, no coherent
    variability is traceable throughout the whole set of flickering data.
Object:
  ----------------------------------------------------
      RA  (2000)  DE         Name
  ----------------------------------------------------
   07 23 25.9   -07 38 03    MWC 560 = V694 Mon
  ----------------------------------------------------

File Summary:

       FileName      Lrecl  Records   Explanations

ReadMe            80        .   This file
table1            37      140   UBV photoelectric photometry
table2            15      682   Visual brightness estimates of MWC560 from
                                  Nelson (New Zealand)


See also:
  J/A+AS/122/43 : V694 Mon plate spectra (Tomov+ 1997)


Byte-by-byte Description of file: table1

   Bytes Format Units   Label     Explanations

   1- 11  F11.3 d       JD        Date of the observation
  13- 17  F5.2  mag     Vmag      Star's magnitude in V band
      18  A1    ---     u_Vmag    Uncertainty flag on Vmag
  20- 23  F4.2  mag     B-V       B-V colour
      24  A1    ---     u_B-V     Uncertainty flag on B-V
  26- 30  F5.2  mag     U-B       []? U-B colour
      31  A1    ---     u_U-B     Uncertainty flag on U-B
      33  I1    ---     o_Vmag    Number of independent measurements
  35- 37  A3    ---     Obs       Identification of the Observatory (1)

Note (1): The observatories are:
            Roz = Bulgarian National Astronomical Observatory Rozhen,
            Bel = Belogradchik Astronomical Observatory,
            Kry = Kryoneri Observatory in Greece,
            Tor = Torun Observatory in Poland,
            Ols = Olsztyn Observatory in Poland,
            Suh = Mt. Suhora Observatory in Poland,
            Rem = Remanzacco Observatory of the Assoziazione Friulana di
                   Astronomia e Meteorologia (Italy).


Byte-by-byte Description of file: table2

   Bytes Format Units   Label     Explanations

   1- 10  F10.2 d       JD        Date of the observation
  12- 15  F4.1  mag     Vmag      Visual brightness estimates


Courtesy: T. Tomov, 

(End)                                        Patricia Bauer  [CDS]   15-Jan-1996