- ID:
- ivo://CDS.VizieR/J/A+A/415/283
- Title:
- BV light curves of NN Vir
- Short Name:
- J/A+A/415/283
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Photoelectric BV light curves of the recently discovered eclipsing binary NN Vir were studied for the first time to derive the physical parameters of the system. The light curves were obtained at the Ankara University Observatory during three nights in May, 2002. The solutions made by using Djurasevic's inverse problem method describe the NN Vir system as a high overcontact configuration (f_over_~58%) with a relatively small temperature differences between the components ({Delta}T=T_h_-T_c_~160K). These solutions suggest a significant mass and energy transfer from the more massive primary onto the less massive secondary. The hot area on the less massive star, near the neck region, can be taken as a consequence of this mass and energy exchange between the components through the connecting neck of the common envelope.
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Search Results
- ID:
- ivo://CDS.VizieR/J/AJ/139/2014
- Title:
- BV light curves of 11 RR Lyrae
- Short Name:
- J/AJ/139/2014
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- It is not easy to identify and classify low-amplitude variables, but it is important that the classification is done correctly. We use photometry and spectroscopy to classify low-amplitude variables in a 246deg^2^ part of the Akerlof et al. (2000, Cat. J/AJ/119/1901) field. Akerlof and Collaborators found that 38% of the RR Lyrae stars in their 2000deg^2^ test field were RR1 (type c). This suggests that these RR Lyrae stars belong to an Oosterhoff Type II population, while their period distribution is primarily Oosterhoff Type I. Our observations support their RR0 (type ab) classifications; however, six of the seven stars that they classified as RR1 (type c) are eclipsing binaries. Our classifications are supported by spectroscopic metallicities, line-broadening, and Galactic rotation measurements. Our 246deg^2^ field contains 16 RR Lyrae stars that are brighter than m_R_=14.5; only four of these are RR1 (type c). This corresponds to an Oosterhoff Type I population in agreement with the period distribution.
- ID:
- ivo://CDS.VizieR/J/AJ/144/136
- Title:
- BV light curves of the Algol-type binary V1241 Tauri
- Short Name:
- J/AJ/144/136
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present new photometry for the eclipsing binary V1241 Tau, which was obtained on six nights between 2011 December and 2012 January using the 85cm telescope at the Xinglong station of the National Astronomical Observatories of China. By using the updated Wilson-Devinney code, photometric models with third lights were deduced from two sets of light curves. The result implies that V1241 Tau is an Algol-type near-contact binary (NCB), whose mass ratio and filling-out of the primary are q=0.545(+/-0.003) and f_1_=82.4% (+/-0.2%), respectively. Based on all available times of minimum light spanning over 80yr, the O-C curve of V1241 Tau appears to show a quasi-sinusoidal oscillation, i.e., a light-time orbit. The modulated period and amplitude are P_mod_=47.4(+/-1.7)yr and A=0.0087(+/-0.0005)days, respectively. This kind of period variation may be more likely attributed to the light-time effect via a presence of an unseen third body. From an analysis of 23 Algol-type NCBs with EB-type light curves, we determine that the fill-out for the primary f_1_ will increase as the orbital period P decreases. With angular momentum loss, the orbit of the binary will shrink, which causes f_1_ to increase. The primary component finally fills its Roche lobe, and the binary evolves into contact configuration. Therefore, this kind of Algol-type NCB with EB-type light curves, such as V1241 Tau, may be a progenitor of the A-type W UMa binary.
- ID:
- ivo://CDS.VizieR/J/A+A/383/197
- Title:
- BV light curves of V511 Lyr in 1994-1996
- Short Name:
- J/A+A/383/197
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Our time series analysis of sixteen BV light curves of the chromospherically active binary V511 Lyr confirmed the 2.7days rotation period uniquely. The seasonal periodicity changes of 3.8% indicated the presence of detectable surface differential rotation. The significant 2.67455days periodicity in the light curve minimum epochs suggested that the strongest starspot formation in V511 Lyr was concentrated on one stable active longitude. The differential BV photometry of V511 Lyr was made between May 1994 and June 1996 with the Vanderbilt-Tennessee State 0.4m Automated Photoelectric Telescope (APT). The comparison and check stars were HDE 337663 (C1) and HD 179422 (C2).
- ID:
- ivo://CDS.VizieR/J/A+A/418/249
- Title:
- BV light curves of WX Eridani
- Short Name:
- J/A+A/418/249
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- WX Eri is an eclipsing binary system for which one component was reported to show Delta Scuti type pulsations with periods close to integer fractions of the orbital period. This makes it an interesting candidate for investigating the interaction between binarity and pulsation and a potential new member of the recently defined group of mass-accreting pulsating components (gainers) in semi-detached Algol binaries called 'oscillating EA' stars. We present new photometric time-series observations of this star. The Wilson-Devinney code was applied to find the best fitting model for the eclipsing binary's light curve. The aim of the observations was to investigate the short-period Delta Scuti type pulsations of WX Eri. However, no evidence for the presence of such oscillations was found in our data.
- ID:
- ivo://CDS.VizieR/J/other/PASA/23.154
- Title:
- BV light curves of XY Leo, EE Cet, AQ Psc
- Short Name:
- J/other/PASA/23.
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- New photoelectric BV light curves of three close eclipsing binaries XY Leo, EE Cet and AQ Psc were observed at the Rozhen National Astronomical Observatory, Bulgaria in the period October 2004 - February 2005, by using the 0.6-m Cassegrain telescope, equipped with an UBV, single-channel, photon-counting, computer controlled photometer. Integration time of 10 seconds was chosen.
- ID:
- ivo://CDS.VizieR/J/A+AS/105/47
- Title:
- B,V photoelectric obs. of V505 Sgr
- Short Name:
- J/A+AS/105/47
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- (no description available)
- ID:
- ivo://CDS.VizieR/J/ApJ/652/313
- Title:
- BV phot. of a detached eclipsing binary in M 33
- Short Name:
- J/ApJ/652/313
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the first direct distance determination to a detached eclipsing binary in M33, which was found by the DIRECT Project. Located in the OB 66 association at coordinates (RA,DE)=(01:33:46.17,+30:44:39.9) for J2000.0, it was one of the most suitable detached eclipsing binaries found by DIRECT for distance determination, given its apparent magnitude and orbital period. We obtained follow-up BV time-series photometry, JHKs photometry, and optical spectroscopy from which we determined the parameters of the system. It contains two O7 main-sequence stars, with masses of 33.4+/-3.5 and 30.0+/-3.3M_{sun}_ and radii of 12.3+/-0.4 and 8.8+/-0.3R_{sun}_, respectively. We derive temperatures of 37000+/-1500 and 35600+/-1500K. Using BVRJHKs photometry for the flux calibration, we obtain a distance modulus of 24.92+/-0.12mag (964+/-54kpc), which is 0.3mag longer than the Key Project distance to M33. We discuss the implications of our result and the importance of establishing M33 as an independent rung on the cosmological distance ladder.
- ID:
- ivo://CDS.VizieR/J/A+A/475/539
- Title:
- BV photometry and Li abundances in NGC3960
- Short Name:
- J/A+A/475/539
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Old open clusters are very useful targets to investigate mechanisms responsible for lithium (Li) depletion during the main sequence. Comparison of the Li abundances in clusters of different age allows us to understand the efficiency of the Li destruction process. To determine the membership and Li abundance in a sample of candidate members of the open cluster NGC 3960 (age ~1Gyr), aiming to fill the gap between 0.6 and 2Gyr in the empirical description of the behavior of the average Li abundance as a function of the stellar age. We use VLT/FLAMES Giraffe spectra to determine the radial velocities and thus the membership of a sample of 113 photometrically selected candidate cluster members. From the analysis of the Li line we derive Li abundances for both cluster members and non-members. 39 stars have radial velocities consistent with membership, with an expected fraction of contaminating field stars of about 20%. Li is detected in 29 of the radial velocity members; we consider these stars as cluster members, while we make the reasonable assumption that the remaining 10 radial velocity members without Li are among the contaminating stars. Li abundances of the stars hotter than about 6000K are similar to those of stars in the Hyades, while they are slightly smaller for cooler stars. This confirms that NGC 3960 is older than the Hyades. The average Li abundance of stars cooler than about 6000K indicates that the Li Pop. I plateau might start at ~1Gyr, rather than 2Gyr, which is the upper limit previously derived in the literature. We also find that the fraction of field stars with high Li abundance (>1.5) is about one third of the whole sample, which is in agreement with previous estimates. The fraction of contaminating field stars is consistent with that previously derived by us from photometry.
- ID:
- ivo://CDS.VizieR/J/A+A/356/141
- Title:
- BV photometry for components of HIP doubles
- Short Name:
- J/A+A/356/141
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Using observations obtained with the Tycho instrument of the ESA Hipparcos satellite, a two-colour photometry is produced for components of more than 7000 Hipparcos double and multiple stars with angular separations 0.1 to 2.5 arcsec. We publish 9473 components of 5173 systems with separations above 0.3 arcsec. The majority of them did not have Tycho photometry in the Hipparcos catalogue. The magnitudes are derived in the Tycho B_T and V_T passbands, similar to the Johnson passbands. Photometrically resolved components of the binaries with statistically significant trigonometric parallaxes can be put on an HR diagram, the majority of them for the first time.
