- 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.
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- 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.
- ID:
- ivo://CDS.VizieR/J/other/NewA/31.65
- Title:
- BVRcIc light curves of LU Lac
- Short Name:
- J/other/NewA/31.
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- LU Lac is a neglected W UMa binary star in photometric investigations. In this paper, we present BVRI CCD photometric light curves obtained on one night in 2012. The first photometric solutions of this system are computed by using the Wilson-Devinney code. It is shown that LU Lac is a marginal contact W-type system with a degree of contact factor of f=8.9%, a mass ratio of q=2.085 and a high inclination of i=82.20{deg}. From the first analyses of orbital period changes, we found the period variation of the system includes an oscillation (A3=0.0125-days and T3=51.92-years). The cyclic change may be attributed to the light-travel time effect through the presence of a third body.
- ID:
- ivo://CDS.VizieR/J/AJ/152/219
- Title:
- BV(RI)c light curves of DD Indi
- Short Name:
- J/AJ/152/219
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Observations and a 2015 Wilson-Devinney Program analysis are undertaken for the first precision observations of DD Indi. DD Indi is of solar-type (T_1_~5750K) and was determined to be a shallow-contact eclipsing binary. It was observed from 2013 June through September at Cerro Tololo InterAmerican Observatory in remote mode. The 24 inch Boller and Chivens reflector, now under management by The Southeastern Association for Resarch in Astronomy (SARA) was used. Five new eclipse timings were obtained, for three primary and two secondary eclipses. Seven more eclipse timings were calculated from All Sky Automated Survey data. A possibly increasing period was found from all available eclipse timings with a 5+/-2x10^-11^xE^2^ quadratic term. A BVR_c_I_c_ simultaneous synthetic light-curve analysis reveals that the system has a mass ratio of ~0.46, a ~140K component temperature difference, and two weak cool spots. The Roche Lobe fill-out of this W-type binary is only ~11%, and an inclination of ~86{deg} was determined. A time of constant light of ~16 minutes is measured around phase zero. More detail is included in this report.
- ID:
- ivo://CDS.VizieR/J/AJ/152/199
- Title:
- BV(RI)c light curves of FF Vul
- Short Name:
- J/AJ/152/199
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- High-precision BVR_c_I_c_ light curves of FF Vul were taken during the fall of 2015 with the Dark Sky Observatory 0.81m reflector of Appalachian State University, and the SARA north 0.91m reflector at KPNO. FF Vul is an eclipsing binary with a period of 0.44 day. A Wilson-Devinney solution shows that the binary is a near-contact, semidetached binary, i.e., with a V1010 Oph-type configuration. Five eclipse timings (three primary and two secondary) were calculated. A quadratic ephemeris was determined indicating that the period is decreasing. A near-equatorial hot spot was modeled on the cooler, secondary star, possibly caused by matter impacting from the primary component via the inner Lagrangian point. The component temperature difference is more than 1500K. The solution confirms a total secondary eclipse of 23 minutes duration. As expected in binaries of this type, there is a magnetic spot region.
- ID:
- ivo://CDS.VizieR/J/AJ/152/227
- Title:
- BV(RI)c light curves of NSVS 5066754
- Short Name:
- J/AJ/152/227
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- BVR_c_I_c_ light curves of NSVS 5066754 were taken on 2014 May at Dark Sky Observatory in North Carolina. This variable is a solar-type eclipsing binary (T1~5750K) with a period of only 0.3751689(1) days. It appeared to be one of the shortest periods in Shaw's list of near-contact binaries. The Binary Maker fits and our Wilson-Devinney solutions show that the binary could have both semidetached and marginal contact binary configurations. Five new times of minimum light were calculated, along with two minima determined from archived All Sky Automated Survey observations. From these minima and the discovery epoch, a quadratic ephemeris was determined. Thus, a magnetic braking scenario is possible. Both semidetached and contact models were explored. A marginal contact solution had the best sum of square residuals. It gave a mass ratio of ~0.5, and a component temperature difference of ~360K, albeit somewhat large for a contact binary. Two substantial cool spots were determined in this solution with 37{deg} and 28{deg} radii and t-factors or 0.94 and 0.78 respectively. The fill-out is very shallow, ~106%. It may have recently achieved contact.
- ID:
- ivo://CDS.VizieR/J/AJ/145/14
- Title:
- BV(RI)c light curves of V1043 Cas
- Short Name:
- J/AJ/145/14
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Complete Bessel BVR_c_I_c_ light curves of V1043 Cassiopeia [2MASS J00371195+5301324, Mis V1292, USNO-A2.0 1425-00875743, {alpha}(2000)=00^h^37^m^11.95^s^, {delta}(2000)=+53{deg}01'32.5"] are analyzed. The system is a member of the small group of pre-contact W UMa binaries (PCWBs). Its light curve has the appearance of an Algol (EA) light curve, however it is made up of dwarf solar type components in a detached mode with a period of only 0.6616days. The analysis includes a period study, an improved ephemeris, a mass ratio search, and a simultaneous BVR_c_I_c_ Wilson-Devinney solution. We document about 20 other PCWBs given in the literature. Several have RS CVn-like properties.
- ID:
- ivo://CDS.VizieR/J/AJ/147/3
- Title:
- BV(RI)c light curves of V2421 Cyg
- Short Name:
- J/AJ/147/3
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the first precision BVRI light curves, synthetic light curve solutions, and a period study for the high amplitude solar type binary, V2421 Cygni. The light curves have the appearance of an Algol (EA) type; however, it is made up of dwarf solar type components in a detached mode with a period of only 0.6331 days with an amplitude of about a full magnitude, i.e., it is a precontact W UMa binary. Flare-like disruptions occur in the light curves following the primary and secondary eclipses possibly due to the line-of-sight track of a gas stream. An associated stream spot and splash spot cause bright equatorial spots on the stellar surface of the primary star. The more massive star is the gainer, making this system a classic, albeit dwarf, Algol.
- ID:
- ivo://CDS.VizieR/J/AJ/149/30
- Title:
- BVRI differential photometry of V1001 Cas in 2012
- Short Name:
- J/AJ/149/30
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A 2012 follow up to the analysis of 2009 observations is presented for the very short period (~0.43days) precontact W UMa binary (PCWB) V1001 Cassiopeia. Its short period, similar to the majority of W UMa binaries, and its distinct EA light curve make it a very rare and interesting system for continuing photometric investigation. Previous photometric VRI standard magnitudes give a K4 spectral type. Our solutions of light curves separated by some three years give approximately the same physical parameters. However, the spots have radically changed in temperature, area, and position. While only one dark spot was used to model the first curves, two hot spots are now needed. This affects the overall shape of the light curve, especially in the secondary eclipses in B and V. Additional eclipse timings now show that the orbital period is changing. We conclude that spots are very active on this solar-type dwarf system and that it may mimic its larger cousins, the RS CVn binaries. The conclusion is that analysis now needs to be directed at the continuous time evolution of PCWBs.
- ID:
- ivo://CDS.VizieR/J/A+A/542/A78
- Title:
- BVRI light curves and RV curves of 65 UMa
- Short Name:
- J/A+A/542/A78
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The study of stellar multiple systems provides us with important information about the stellar formation processes and can help us to estimate the multiplicity fraction in the Galaxy. 65 UMa belongs to a rather small group of stellar systems of higher multiplicity, whose inner and outer orbits are well-known. This allows us to study the long-term stability and evolution of the orbits in these systems. We obtained new photometric and spectroscopic data that when combined with interferometric data enables us to analyze the system 65 UMa and determine its basic physical properties.