- 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.
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- 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/459/321
- Title:
- BV photometry of M31 eclipsing binaries
- Short Name:
- J/A+A/459/321
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Broad band photometry (in Johnson B and V) has been obtained in a region (34'x34') at the North-Eastern quadrant of M31 over 5 years (1999-2003) at the Isaac Newton Telescope (La Palma, Spain). The data, containing more than 250 observations per filter, have been reduced by means of the so-called difference image analysis technique and the DAOPHOT program. A catalog with 236238 objects with photometry in both B and V passbands has been obtained. The catalog is the deepest (V<25.5mag) obtained so far in the studied region and contains 3964 identified variable stars, with 437 eclipsing binaries and 416 Cepheids.
- ID:
- ivo://CDS.VizieR/J/A+A/483/253
- Title:
- BV photometry of NGC 2099 variables
- Short Name:
- J/A+A/483/253
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Rotation and solar-type magnetic activity are closely related to each other in main-sequence stars of G or later spectral types. The presence and level of magnetic activity depend on star's rotation, and rotation itself is strongly influenced by strength and topology of the magnetic fields. Open clusters represent especially useful targets to investigate the connection between rotation and activity. The open cluster NGC 2099 has been studied as a part of the RACE-OC project (Rotation and ACtivity Evolution in Open Clusters), which is aimed at exploring the evolution of rotation and magnetic activity in the late-type members of open clusters of different ages. We collected time series CCD photometric observations of this cluster in January 2004, and we determined the presence of periodicities in the flux variation related to the stellar rotation by Fourier analysis. We investigate the relations between activity manifestations, such as the light curve amplitude, and global stellar parameters. We have discovered 135 periodic variables, 122 of which are candidate cluster members. Determination of rotation periods of G- and K-type stars has allowed us to better explore the evolution of angular momentum at an age of about 500Myr. In our analysis, we have also identified 3 new detached eclipsing binary candidates among cluster members. A comparison with the older Hyades cluster (~625Myr) shows that the newly-determined distribution of rotation periods is consistent with the scenario of rotational braking of main-sequence spotted stars as they age. However, a comparison with the younger M34 cluster (~200Myr) shows that the G8-K5 members of these clusters have the same rotation period distribution. That is, G8-K5 members in NGC 2099 seem to have experienced no significant braking in the age range from ~200 to ~500Myr. Finally, NGC 2099 members have a smaller level of photospheric magnetic activity, as measured by light curve amplitude, than in younger stars of the same mass and rotation, suggesting that the activity level also depends on some other age-dependent parameters.
- ID:
- ivo://CDS.VizieR/J/AJ/152/120
- Title:
- BV photometry of V532 Mon
- Short Name:
- J/AJ/152/120
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The first two sets of complete charge-coupled device light curves in the B and V bands of the short-period binary system, V532 Mon, are presented. The light curves are analyzed with spot models using the Wilson-Devinney code. V532 Mon is found to be an A-subtype intermediate-contact binary with a degree of contact factor of f=47.1%(+/-2.7%), a mass ratio of q=0.2502(+/-0.0019), and a cool spot on the primary component. The period changes of the system are investigated by combining newly determined times of light minimum with others published in the literature. We found that the general trend of the observed-calculated (O-C) curve shows a downward parabolic variation that corresponds to a long-term decrease in the orbital period at a rate of dP/dt=-1.716(+/-0.002)*10^-7^dyr^-1^. The long-term decrease of the orbital period can be explained by mass transfer from the more-massive component to the less massive one. The long-time period decrease, the intermediate-contact configuration, and the astrophysical parameters of the binary system suggest that V532 Mon will evolve into high fill-out, extreme mass-ratio overcontact binaries.
- ID:
- ivo://CDS.VizieR/J/AJ/157/207
- Title:
- BVR_c_I_c_ light curve observations for VZ Lib
- Short Name:
- J/AJ/157/207
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- VZ Lib is a southern triple-lined system. By analyzing all available times of light minima, orbital period changes are revisited in detail. We discovered that the observed-calculated (O-C) curve shows a long-term period decrease at a rate of dP/dt=-2.25x10^-7^ days/yr, revealing a mass transfer from the more massive component to the less massive one. A cyclic variation covering more than three cycles was discovered, which was analyzed for the light-travel-time effect via the presence of the tertiary companion. The cyclic variation has a short period of 2.96 (+/-0.04) yr and a small semiamplitude of 0.0039 (+/-0.0004) days. The mass of the third body was determined to be M_3_sini_3_=0.52 (+/-0.07) M_{sun}_ and an orbital semimajor axis shorter than 1.93 (+/-0.31) au was obtained. Orbital properties of this close-in companion should provide valuable information on the formation of close binaries and stellar dynamical interaction. New complete BVR_c_I_c_ light curves of VZ Lib were obtained and modeled with the Wilson-Devinney code. The light curves show a small but significant O'Connell effect that was not detectable in 1981 and 2007 but in 2004, so we derived a new photometric solution with assuming spot and a third light in the system. It is found that the light-curve subtype changed from A-type to W-type, which was possibly caused by a dark spot on the massive component. Our photometric solutions are in agreement with the spectroscopic results given by previous authors.
- ID:
- ivo://CDS.VizieR/J/AJ/160/175
- Title:
- BVRcIc light curve of eclisping binary V1023 Persei
- Short Name:
- J/AJ/160/175
- Date:
- 09 Dec 2021
- Publisher:
- CDS
- Description:
- V1023 Per is a polar spotted, but well-detached dwarf binary, very likely a Pre-WUMa eclipsing binary. It was observed on 11 nights in 2015 October, November, and December at Dark Sky Observatory in North Carolina with the 0.81m reflector of Appalachian State University. The period behavior is complex and may be increasing with a cubic or quadratic ephemeris. Its odd light curves are of high amplitude but have no totality and reach maximum light just before and following the secondary eclipse, indicating that it has polar spots similar to UV Leo. The 28yr orbital period study calls the attention of observers to further monitor this binary to understand the complex nature of the period evolution. Its presently fixed polar spot does indicate that it must have a strong magnetic field and that it is synchronously rotating. The BVRcIc simultaneous 2016 Wilson-Devinney program (W-D) solution gives fillouts of 68% and 75% for the primary and secondary components, respectively. The polar position of the spot, its radius (24{deg}), and T-fact (0.75) indicate that a strong magnetic field is present. The small {Delta}T in the components (~289K) show that the stars are similar in spectral type despite them being well detached. The inclination is high, ~85.19{deg}{+/-}0.04{deg}, but there is not a total eclipse due to the high mass ratio (~0.739{+/-}0.001). Due to the low galactic position (longitude=150.390{deg}, latitude=-1.023{deg}), its reddening is addressed. The primary components temperature is estimated to be 5250{+/-}250K.
