VizieR Online Data Catalog: Long-Term Photometry of five PMS stars (Semkov+, 2019)

The photometric UBVRI data were collected in the period from February 1998 to November 2016. The CCD observations were obtained with four telescopes, in two observatories - the 2-m Ritchey-Chretien-Coude (RCC), the 50/70-cm Schmidt and the 60-cm Cassegrain telescopes of the Rozhen National Astronomical Observatory (NAO) in Bulgaria, and the 1.3-m Ritchey-Chretien (RC) telescope of the Skinakas Observatory of the University of Crete in Greece. The total number of the nights used for observations is 295. The observations were performed with eight different types of CCD cameras. Their technical parameters and specifications are given in Ibryamov et al. (2015PASA...32...21I, Cat. J/other/PASA/32.21). All frames were taken through a standard Johnson- Cousins UBVRI set of filters. The frames obtained with the CCD cameras at the 2-m RCC and the 1.3-m RC telescopes are bias frame subtracted and flat field corrected. All frames obtained with the CCD cameras at the 50/70-cm Schmidt and the 60-cm Cassegrain telescopes are dark frame subtracted and flat field corrected. The photometric data were reduced using the IDL based DAOPHOT subroutine. As a reference, the UBVRI comparison sequence reported in Semkov (2003IBVS.5373....1S) was used. All data were analyzed using the same aperture, which was chosen as 6 arcsec radius, while the background annulus was taken from 10 to 15 arcsec.

(6 data files).