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- ID:
- ivo://CDS.VizieR/J/AJ/113/2104
- Title:
- UBV photometry of 163 stars around SU Cyg
- Short Name:
- J/AJ/113/2104
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Photoelectric, CCD, and photographic photometry is presented for a sample of 163 stars in the field of the short-period Cepheid SU Cyg for the purpose of searching for a putative cluster that might be associated with the Cepheid. Although the variable is situated in a clump of stars that has the appearance of a sparse cluster, the photometric evidence indicates that they are not a physical group. About two dozen B and A-type stars randomly distributed in the field lie at a common distance of 1086+/-60pc (V_0_-M_V_= 10.18+/-0.12 for R=2.94+/-0.38), but they are likely to represent at best a segment of the Vul OB4 association, which overlaps the region. SU Cyg is unlikely to be a member of that group. The close optical companion to SU Cyg, an A2 V star with a radial velocity (<VR>=-23.6+/-7.1km/s) close to the systemic velocity of the Cepheid, is a spectroscopic binary that might be physically related to the variable. Its primary importance is for helping to establish a space reddening of E_(B-V_)=0.15+/-0.01 for SU Cyg. Despite the lack of related cluster stars to SU Cyg, its two unresolved companions can be used to place restrictions on the likely luminosity of the Cepheid. The resulting value of <M_V_><=-3.02+/-0.23 relative to its companions agrees closely with a value of <MV>(PLC)=-3.03+/-0.07 obtained from the Cepheid PLC relation.
- ID:
- ivo://CDS.VizieR/J/PAZh/26/535
- Title:
- UBV photometry of UV Cas
- Short Name:
- J/PAZh/26/535
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- UBV observations of UV Cas during 1996-1999 show mostly irregular light variations.
- ID:
- ivo://CDS.VizieR/J/other/JAD/17.1
- Title:
- 1961-1999 UBV photometry of 14 variables
- Short Name:
- J/other/JAD/17.1
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Photoelectric UBV photometry of the variable stars V636 Cas, alpha UMi, V440 Per, zeta Gem, UU Cnc, TYC2-880-515-1, V473 Lyr, chi Cyg, V1794 Cyg, DT Cyg, V1334 Cyg, V532 Cyg, pi Aqr, and DY Peg is reported.
- ID:
- ivo://CDS.VizieR/J/AJ/142/117
- Title:
- UBVrcIc differential photometry of V1853 Ori
- Short Name:
- J/AJ/142/117
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present precision CCD light curves, a period study, photometrically derived standard magnitudes, and a five-color simultaneous Wilson code solution of the totally eclipsing, yet shallow amplitude (Av~0.4mag) eclipsing, binary V1853 Orionis. It is determined to be an extreme mass ratio, q=0.20, W-type W UMa overcontact binary. From our standard star observations, we find that the variable is a late-type F spectral-type dwarf, with a secondary component of about 0.24 solar masses (stellar type M5V). Its long eclipse duration (41 minutes) as compared to its period, 0.383-days, attests to the small relative size of the secondary. Furthermore, it has reached a Roche lobe fill-out of ~50% of its outer critical lobe as it approaches its final stages of binary star evolution, that of a fast spinning single star. Finally, a summary of about 25 extreme mass ratio solar-type binaries is given.
- ID:
- ivo://CDS.VizieR/J/AZh/87/462
- Title:
- UBV(RI)c light curves of BD+66 1663
- Short Name:
- J/AZh/87/462
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have obtained the first UBV(RI)C photoelectric light curves of the recently discovered eclipsing binary BD+66 1663 = GSC 4479 412 (P=7.04d, V=10.14). We have derived relative and absolute parameters of the binary, and analyzed the interstellar extinction towards the object. Though the star is located in the field of the young open cluster Be 59, we demonstrate that it is not a member.
- ID:
- ivo://CDS.VizieR/J/A+AS/119/281
- Title:
- UBV(RI)c photometry of active stars.
- Short Name:
- J/A+AS/119/281
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- High-precision UBV(RI)_c_ photometry of 12 selected active stars, collected at the European Southern Observatory (La Silla, Chile) over the period February-March 1990, is presented. Significant evolution of the light curves, period variations and, in most cases, evidence for long-term variability of the global degree of spottedness are found. Some of the spectral classifications are discussed. This paper is part of a more extensive program focusing on the global properties and evolution of active stars and is aimed at establishing a time-extended photometric database which can give important clues on topics such as the stability of the spotted areas, differential rotation and solar-like cycles. For a description of the UBV and (RI)c photometric systems, see e.g. General Catalog of Photometric Data <GCPD/01> and <GCPD/54>.
- ID:
- ivo://CDS.VizieR/J/A+A/367/910
- Title:
- UBV(RI)c photometry of active stars. IX
- Short Name:
- J/A+A/367/910
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- As a part of an extensive program focused on the global properties and evolution of active stars, high-precision UBV(RI)_c_ and UBV photometry of 31 selected stars is presented. The UBV(RI)_c_ observations were collected at the European Southern Observatory over the 31 December 1992-18 January 1993 and the 20 November-3 December 1993 intervals. Additional UBV photometry obtained by the ``Phoenix" and by the Catania Astrophysical Observatory Automatic Photoelectric Telescopes from 1990 to 1993 is also presented for some of the program stars. Significant evolution of the light curves, period variations and evidence for long-term variability of the global degree of spottedness are found. Some spectral classifications are revised and the inferred photometric parallaxes are compared, whenever possible, with the values measured by the Hipparcos satellite (Cat. <I/239>). These observations are finalized to the construction of an extended photometric database, which can give important clues on topics such as the stability of spotted areas, differential rotation, solar-like cycles and the correlation between inhomogeneities at different atmospheric levels.
- ID:
- ivo://CDS.VizieR/J/A+AS/127/207
- Title:
- UBV(RI)c photometry of active stars. VII.
- Short Name:
- J/A+AS/127/207
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In the framework of an extensive program focusing on the global properties and evolution of active stars, high-precision UBV(RI)c photometry of 19 selected stars, collected at ESO over the 15-31 March 1991 interval is presented. Significant evolution of the light curves, period variations and evidence for long-term variability of the global degree of spottedness are found. Most of the spectral classification are discussed. A flare event was detected for the star HD 127535 = V841 Cen. These observations contribute to the establishment of a time-extended photometric database which can give important clues on topics such as the stability of spotted areas, differential rotation, solar-like cycles and the correlation between inhomogeneities at different atmospheric levels.
- ID:
- ivo://CDS.VizieR/J/A+A/400/659
- Title:
- UBV(RI)c photometry of active stars. X.
- Short Name:
- J/A+A/400/659
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- As part of an extensive program focused on the global properties and evolution of active stars, high-precision UBV(RI)c and UBV photometry of 18 selected stars is presented. UBV(RI)c observations were collected at the European Southern Observatory over the intervals 21-28 September 1994 and 25 November - 05 December 1994. Additional UBV photometry obtained late in 1994 by Catania Astrophysical Observatory Automatic Photoelectric Telescope is also presented. Significant evolution of the light curves, period variations and evidence for long-term variability of the global degree of spottedness are found. Some spectral classifications are revised and photometric parallaxes are compared, whenever possible, with the values measured by the Hipparcos satellite. These observations are finalized to the construction of an extended photometric database, which can give important clues on topics such as the stability of spotted areas, differential stellar rotation, solar-like activity cycles and the correlation between inhomogeneities at different atmospheric levels.