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- 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.
- ID:
- ivo://CDS.VizieR/J/MNRAS/407/1070
- Title:
- UBV(RI)c photometry of LL Cas
- Short Name:
- J/MNRAS/407/1070
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Accurate BV(RI)c light and colour curves of the Mira variable in the dust-free symbiotic system K4-46 are presented and discussed. They cover several consecutive pulsations cycles. The Mira mean period is 284.2d, the reddening sums to E(B-V)=0.35 and the distance is 10kpc. Absolute spectrophotometry at both maximum and minimum brightness of the Mira is presented.
- ID:
- ivo://CDS.VizieR/J/A+AS/122/415
- Title:
- UBVRIc photometry of 12 LPVs
- Short Name:
- J/A+AS/122/415
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A program of (UBVRI)c photometric observations of twelve southern hemisphere Long Period Variables (LPV or Miras) has been carried out at the European Southern Observatory. Each star was observed on at least 11 occasions up to 29 over a 4-year period. A determination of their spectral types and their distance was also performed. We therefore present for the first time spectral type variations together with visible and colour light-curves for at least three successive cycles.
- ID:
- ivo://CDS.VizieR/J/A+A/386/237
- Title:
- UBV(RI)c photometry of 7 symbiotic stars
- Short Name:
- J/A+A/386/237
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Asiago photographic archive has been searched for plates containing the symbiotic stars Hen 2-468, QW Sge, LT Del, V407 Cyg, K 3-9, V335 Vul, FG Ser and Draco C-1. A total of 635 plates imaging the program stars have been found and the brightness estimated using the Henden & Munari (2000A&AS..143..343H) UBV(RI) photometric sequences. These historical data have allowed for the first time the determination of the orbital periods of Hen 2-468 (774 days) and QW Sge (390.5 days), a significant improvement in the orbital period of LT Del (465.6 days) and for V407 Cyg an evaluation of the Mira's pulsation period and complex lightcurve shape in the red (R and I bands). Some previously unknown outbursts have been discovered too.
