UV Piscium Research Articles

Magnetic field of the eclipsing binary UV Piscium

Aims. The goal of this work is to study magnetic fields of the cool, eclipsing binary star UV Piscium (UV Psc). This system contains two active late-type stars, UV Psc A (G5V) and B (K3V). To obtain a complete picture, the properties of both global and local magnetic field structures are studied for both components. Methods. High-resolution intensity and circular polarisation spectra, collected in 2016 with the ESPaDOnS spectropolarimeter at the CFHT, were used to analyse the magnetic field of UV Psc. To increase the signal-to-noise ratio, the multi-line technique of least-squares deconvolution (LSD) was used to obtain average Stokes IV profiles. Then, a Zeeman-Doppler imaging (ZDI) code was employed to obtain the large-scale magnetic field topology and brightness distribution for both components of UV Psc. In addition, the small-scale magnetic fields, not visible to ZDI, were studied using the Zeeman intensification of Fe I lines. Results. The orbital and fundamental parameters of the system were revised based on the new radial velocity measurements. Maps of the surface magnetic field for both components of UV Psc were obtained, the large-scale magnetic fields feature strong toroidal and non-axisymetric components. UV Psc A and B have average global field strengths of 137 G and 88 G, respectively. The small-scale fields are notably stronger, with average strengths of 2.5 and 2.2 kG, respectively. Only ∼5% of the total magnetic field strength is recovered with ZDI. Our results are in agreement with previous studies of partly-convective stars. Overall, UV Psc A has a stronger magnetic field compared to UV Psc B. Due to the eclipsing binary geometry, certain magnetic field features are not detectable using circular polarisation only. An investigation into theoretical linear polarisation profiles shows that they could be used to reveal antisymmetric components of the magnetic field. This result also has implications for the study of exoplanetary transit hosts. The successful use of Zeeman intensification shows the method’s ability to extract information on magnetic fields for stars rotating significantly more rapidly than in previous studies.

New Light Curves and Orbital Period Investigations of the Interacting Binary System UV Piscium

New Light Curves and Orbital Period Investigations of the Interacting Binary System UV Piscium

Evolutionary status of UV Piscium and its comparison with other short period RS CVn binaries

From the derived elements of UV Piscium, the evolutionary status of both of its components are compared with the Schaller et al. models and also with other main sequence systems having spectral types of late F to K range. From these models the ages of the components of UV Psc are determined. The Rossby number, which is a measure of chromospheric activity, has been derived from the convective turnover time scales and also from the age estimates.

UV piscium and the radiative flux scale

Studies of eclipsing binaries with Hipparcos parallaxes are found to define a radiative flux relation for main sequence stars in the spectral range from B6 – F0which is about as well as to the stars derived from angular diameters. At lower temperatures the fluxes of the components fall below this curve which is caused due to the large intrinsic variations and starspots. From the present analysis it is found that the secondary component of UV Piscium, a late type eclipsing binary, is a normal K3V star and it fits the radiative flux-colour relation quite satisfactorily. This is explained due to the reliable values of the fluxes and colours derived from the clean light curves (light curves obtained after removing the effect of the distortion wave). However, the primary component which is also responsible for the intrinsic variations and starspots continue to deviate from this curve.

Long-term study of the starspot activity on the eclipsing short-period RS canum venaticorum star UV piscium

We present optical photometry of the short period eclipsing RS CVn system, UV Piscium for the years 1966–1984. After removing the spot effects from the light curves of Vivekananda Rao and Sarma (1981), we analyzed the cleaned data to obtain system parameters. For each light curve, we model the distortion waves in order to study the behaviour of star spots in this system.

Period Changes in Four Short-Period Spotted Binaries: UV Piscium, YY Geminorum, CG Cygni, and XY Ursae Majoris

Recently acquired times of minimum for three RS CVn systems and one BY Draconis binary, all with periods under a day, are presented. Times of minimum for UV Psc, YY Gem, CG Cyg, and XY UMa have been measured for decades. These observations have been collected, and the O-C curves for each system have been examined for period changes. The O-C curves for UV Psc and YY Gem showed a linear deviation, and improved periods have been computed. CG Cyg and XY UMa, though, appear to have experienced true changes in their periods. An additional 11.0 yr periodic variation has been found in the O-C data of XY UMa. The mechanism for the period variations remains uncertain.

Orbits of detached main-sequence eclipsing binaries of types late F to K. II. UV leonis, UV piscium, and BH virginis.

Orbits of detached main-sequence eclipsing binaries of types late F to K. II. UV leonis, UV piscium, and BH virginis.

1992 UBV observations of UV piscium and light curve analysis

In 1992 UBV photometry of short period binary system UV PSc were presented. The results obtained from the analysis ofU, B andV light curves represent “transit” solutions. The light fluctuations of out-side eclipses have been interpreted in terms of cool star-spots on the photosphere of the primary component. Its parameters have been determined.

Orbits of close binaries with CA II H and K in emission. V - The main-sequence system UV PISCIUM

view Abstract Citations (12) References (25) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Orbits of Close Binaries With CA II H and K in Emission. V. the Main-Sequence System UV PISCIUM Popper, Daniel M. Abstract UV Psc is a detached, main-sequence eclipsing binary with period 0.68 d and components of types G and K. Both components have Ca II H and K in emission, but in the blue-violet photographic spectrum only lines of the larger, more massive component are seen in absorption. Results of published photometric analyses are combined with the spectrographic orbits to derive the properties of the components. Because of intrinsic variability in the light of at least the hotter star and possible systematic effects in the secondary velocities, the results are not of high precision. They add, nevertheless, to the very meager supply of fundamental parameters of main-sequence G- and K-type stars. Publication: The Astronomical Journal Pub Date: August 1991 DOI: 10.1086/115904 Bibcode: 1991AJ....102..699P Keywords: Eclipsing Binary Stars; Emission Spectra; Main Sequence Stars; Stellar Composition; Stellar Orbits; Calcium; Light Curve; Orbital Elements; Astrophysics; SPECTROPHOTOMETRY; STARS: ECLIPSING BINARIES full text sources ADS | data products SIMBAD (3) Related Materials (4) Part 1: 1988AJ.....95.1242P Part 2: 1988AJ.....96.1040P Part 3: 1990AJ....100..247P Part 4: 1991AJ....101..220P

A PHOTOMETRIC STUDY OF UV PISCIUM

ABSTRACT New differential UBV photoelectric observations are presented for the short-period, eclipsing binary system UV Piscium which exhibits RS CVn-type phenomena. The data were obtained on nine nights from October 1984 to January 1985 using the 61-cm reflector at the Sobaeksan Astronomical Observatory. These light curves are compared with those observed two years earlier and with still older ones. The asymmetrical distortion wave of this system and the depth of minimum phase are examined. It is also found that the outside-eclipse mean light level of this system was not constant during the last several years.

Two-colour photoelectric photometry of UV piscium and fourier analysis of its out-of-eclipse light variations

Two-colour photoelectric light curves of the RS CVn-type eclipsing system UV Psc, obtained in 1985 and 1986, are presented. Present work also deals with the Fourier analysis of the outside-eclipse light variations for five years' light curves (1981, 1982, 1984, 1985, 1986). Based on this analysis, the amplitude variations of the so-called wave-like distortion and its migration period have been investigated. The amplitude of the wave-like distortion seems to vary with a very rough period of 4–5 years, and the migration period of the wave minimum appears to be one of the three different (2.3, 0.7, 0.4 years) but most possible values among some others.

The light curve variations in UV piscium

Two-colour photoelectric observations of the short-period RS CVn-type eclipsing binary UV Psc have been made between 1981–1986 at the Ege University Observatory. The present work deals with the light curve variations of the binary obtained in the observing seasons of 1981, 1982, and 1984. The shape of the light curve, the depths of the minima, and the total brightness of the system seemed to change in the course of time that covers three years of observing time. The value of the migration period of the wave-like distortion was roughly estimated to be between 1.5 and 2.0 years.

Infrared photometry of UV Piscium

The eclipsing binary system UV Psc was observed in the near-infrared (JHK), and a wave-like distortions have been observed similar to those in the visible. The out-of-eclipse observations have shown real large amount of scatter. This cannot be attributed to the existence of spots on one of the components, which can explain the wave-like distorition of the light curves, but probably to the intrinsic variability of one of them.

The distortion wave on the light curve of the RS CVn binary UV piscium

The eclipsing binary UV Piscium was observed with the standardUBV filters during 1976-77, 1977-78 and 1978-79 observing seasons with the 1.22-m reflecting telescope of the Japal-Rangapur Observatory. A wave-like distortion on the light curve noticed by Carr (1969), Oliver (1974), Sadik (1979) and Zeiliket al. (1982a) is confirmed by the present observations. Combining our observations with those of Carr, Oliver and Sadik, it is found that the distortion wave is moving towards decreasing orbital phase with a period of about 1200 days. The source of the observed distortion wave is found to be the hotter component.

Photoelectric Photomety of UV Piscium.

view Abstract Citations (1) References Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Photoelectric Photomety of UV Piscium. Carr, Roger B. Abstract V) colors have been obtained for the eclipsing binary UV Piscium with a 16-in. telescope at the Kitt Peak National Observatory. The 437 individual observations in each color were com- bined into 68 normal points. The truncated Fourier series representing the normal points outside the eclipses have the coefficients A0 Al A2 B1 B2 V 0.9705 -0.0009 -0.0027 0.0185 -0.0017 +0.0007 +0.0010 +0.0011 +0.0008 +0.0008 B 0.9726 0.0026 -0.0024 0.0199 -0.0020 +0.0006 +0.0009 +0.0010 +0.0007 +0.0007 U 0.9593 0.0126 -0.0077 0.0204 -0.0047 +0.0010 +0.0015 +0.0017 +0.0011 +0.0011 The light curves were rectified with the equations of Russell and Merrill (Contrib. Princeton Univ. Obs. No. 26, 1952). An asymmetry represented by the sine term dominates the rectification. No explanation is offered for the failure of the sign of Al to agree with theory in B and U. A nomographic solution is discussed. This work has been supported by NSF and NASA. Publication: The Astronomical Journal Pub Date: October 1967 DOI: 10.1086/110480 Bibcode: 1967AJ.....72R.788C full text sources ADS |