- ID:
- ivo://CDS.VizieR/J/ApJ/797/31
- Title:
- The G+M eclipsing binary V530 Orionis photometry
- Short Name:
- J/ApJ/797/31
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report extensive photometric and spectroscopic observations of the 6.1 day period, G+M-type detached double-lined eclipsing binary V530 Ori, an important new benchmark system for testing stellar evolution models for low-mass stars. We determine accurate masses and radii for the components with errors of 0.7% and 1.3%, as follows: M_A_=1.0038+/-0.0066 M_{sun}_, M_B_=0.5955+/-0.0022 M_{sun}_, R_A_=0.980+/-0.013 R_{sun}_, and R_B_=0.5873+/-0.0067 R_{sun}_. The effective temperatures are 5890+/-100 K (G1 V) and 3880+/-120 K (M1 V), respectively. A detailed chemical analysis probing more than 20 elements in the primary spectrum shows the system to have a slightly subsolar abundance, with [Fe/H]=-0.12+/-0.08. A comparison with theory reveals that standard models underpredict the radius and overpredict the temperature of the secondary, as has been found previously for other M dwarfs. On the other hand, models from the Dartmouth series incorporating magnetic fields are able to match the observations of the secondary star at the same age as the primary (~3 Gyr) with a surface field strength of 2.1+/-0.4 kG when using a rotational dynamo prescription, or 1.3+/-0.4 kG with a turbulent dynamo approach, not far from our empirical estimate for this star of 0.83+/-0.65 kG. The observations are most consistent with magnetic fields playing only a small role in changing the global properties of the primary. The V530 Ori system thus provides an important demonstration that recent advances in modeling appear to be on the right track to explain the long-standing problem of radius inflation and temperature suppression in low-mass stars.
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Search Results
- ID:
- ivo://CDS.VizieR/J/MNRAS/470/539
- Title:
- The MOA-II eclipsing binary catalogue
- Short Name:
- J/MNRAS/470/539
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the first catalogue of eclipsing binaries in two MOA (Microlensing Observations in Astrophysics) fields towards the Galactic bulge, GB9 and GB10, in which over 8000 candidates, mostly contact and semidetached binaries of periods <1d, were identified. In this paper, the light curves of a small number of interesting candidates, including eccentric binaries, binaries with noteworthy phase modulations and eclipsing RS Canum Venaticorum type stars, are shown as examples. In addition, we identified three triple object candidates by detecting the light-travel-time effect in their eclipse time variation curves.
- ID:
- ivo://CDS.VizieR/J/ApJ/844/66
- Title:
- The Sco-Cen Rotation Catalogue - SCRC
- Short Name:
- J/ApJ/844/66
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report the results of a study of archival SuperWASP light curves for stars in Scorpius-Centaurus (Sco-Cen), the nearest OB association. We use SuperWASP time-series photometry to extract rotation periods for 189 candidate members of the Sco-Cen complex and verify that 162 of those are members of the classic Sco-Cen subgroups of Upper Scorpius (US), Upper Centaurus-Lupus (UCL), and Lower Centaurus-Crux (LCC). This study provides the first measurements of rotation periods explicitly for large samples of pre-main-sequence (pre-MS) stars spanning the UCL and LCC subgroups. Our final sample of 157 well-characterized pre-MS stars spans ages of ~10-20Myr, spectral types of ~F3-M0, and masses of M~=0.3-1.5 M_{sun}_^N^. For this sample, we find a distribution of stellar rotation periods with a median of P_rot_~=2.4-days, an overall range of 0.2<P_rot_<8-days, and a fairly well-defined mass-dependent upper envelope of rotation periods. This distribution of periods is consistent with recently developed stellar angular momentum evolution models. These data are significant because they represent an undersampled age range and the number of measurable rotation periods is large compared to recent studies of other regions. We also search for new examples of eclipsing disk or ring systems analogous to 1SWASP J140747.93-394542.6 (J1407), but find none. Our survey yielded five eclipsing binaries, but only one appears to be physically associated with the Sco-Cen complex. V2394 Oph is a heavily reddened (A_V_~=5mag) massive contact binary in the LDN 1689 cloud whose Gaia astrometry is clearly consistent with kinematic membership with the Ophiuchus star-forming region.
- ID:
- ivo://CDS.VizieR/J/AJ/158/185
- Title:
- Three binary systems in the Large Magellanic Cloud
- Short Name:
- J/AJ/158/185
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the physical properties and apsidal motion elements of three eccentric eclipsing binaries in the Large Magellanic Cloud. The time-series photometric observations were carried out for a total of 41 nights between 2018 November and 2019 February using the KMTNet 1.6 m telescopes installed in South Africa and Australia. The radial velocities of binary components were measured using about 15 spectra per system collected from the ESO Science Archive Facility, which were observed with the Very Large Telescope 8.2 m telescope. The effective temperatures of the more massive binary components were determined to be 19000+/-500 K for OGLE-LMC-ECL-05797, 17000+/-500 K for OGLE-LMC-ECL-05861, and 19000+/-500 K for OGLE-LMC-ECL-06510 by comparing the observed spectra and the stellar atmosphere models obtained from the BOSZ spectral library. The absolute dimensions of each system were derived by analyzing the radial velocity curves together with the light curves obtained from the KMTNet, OGLE, and MACHO observations during about three decades. For the apsidal motion study, new eclipse timings were derived from the KMTNet and survey photometry. The apsidal motion elements of the three binaries were determined from both light curve and eclipse timing analysis. The periods of apsidal motion were 67+/-2 yr for OGLE-LMC-ECL-05797, 124+/-6 yr for OGLE-LMC-ECL-05861, and 39+/-1 yr for OGLE-LMC-ECL-06510 and their internal structure constants (ISCs) were log k_2,obs_=-2.3+/-0.1, -2.4+/-0.1, and -2.1+/-0.1 in the same order. The observed ISCs of OGLE-LMC-ECL-05797 and OGLE-LMC-ECL-05861 showed a good match to the theoretical ISC values, while the value of OGLE- LMC-ECL-06510 was somewhat larger than the theoretical one.
- ID:
- ivo://CDS.VizieR/J/AJ/154/260
- Title:
- Three short-period eclipsing binaries BVRI photometry
- Short Name:
- J/AJ/154/260
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In this paper, we present new BVRI light curves of short-period contact eclipsing binaries V1101 Her and AD Phe from our observations carried out from 2014 to 2015 using the SARA KP and SARA CT telescopes. There is an eclipsing binary located at {alpha}(2000)=01h16m36.15s and {delta}(2000)=-39{deg}49'55.7" in the field of view of AD Phe. We derived an updated ephemeris and found there a cyclic variation overlaying a continuous period increase (V1101 Her) and decrease (AD Phe). This kind of cyclic variation may be attributed to the light time effect via the presence of the third body or magnetic activity cycle. The orbital period increase suggests that V1101 Her is undergoing a mass-transfer from the primary to the secondary component (dM_1_/dt=2.64(+/-0.11)x10^-6^ M_{sun}_/yr) with the third body (P3=13.9(+/-1.9) years), or 2.81(+/-0.07)x10^-6^ M_{sun}_/yr for an increase and magnetic cycle (12.4(+/-0.5) years). The long-term period decrease suggests that AD Phe is undergoing a mass-transfer from the secondary component to the primary component at a rate of -8.04(+/-0.09)x10^-8^ M_{sun}_/yr for a period decrease and the third body (P3=56.2(+/-0.8) years), or -7.11(+/-0.04)x10^-8^ M_{sun}_/yr for a decrease and magnetic cycle (50.3(+/-0.5) years). We determined their orbital and geometrical parameters. For AD Phe, we simultaneously analyzed our BVRI light curves and the spectroscopic observations obtained by Duerbeck & Rucinski (2007AJ....133..169D). The spectral type of V1101 Her was classified as G0+/-2V by LAMOST stellar spectra survey. The asymmetry of the R-band light curve of AD Phe obtained by McFarlane & Hilditch in 1987 (1987MNRAS.227..381M) is explained by a cool spot on the primary component.
- ID:
- ivo://CDS.VizieR/J/MNRAS/495/2713
- Title:
- TIC-231005575 photometric and RV curves
- Short Name:
- J/MNRAS/495/2713
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Transiting Exoplanet Survey Satellite (TESS) has produced a large number of single transit event candidates which are being monitored by the Next Generation Transit Survey (NGTS). We observed a second epoch for the TIC-231005575 system (Tmag=12.06, Teff=5500+/-85K) with NGTS and a third epoch with Las Cumbres Observatory's (LCO) telescope in South Africa to constrain the orbital period (P=61.777d). Subsequent radial velocity measurements with CORALIE revealed the transiting object has a mass of M2=0.128+/-0.003M_{sun}_, indicating the system is a G-M binary. The radius of the secondary is R2=0.154+/-0.008R_{sun}_ and is consistent with models of stellar evolution to better than 1-{sigma}.
- ID:
- ivo://CDS.VizieR/J/other/NewA/35.48
- Title:
- Time minima of EP Aur
- Short Name:
- J/other/NewA/35.
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present new observations for the eclipsing binary EP Aurigae, which were performed by using three small telescopes in China from 2003 December to 2014 January. With the updated 2003 version of the Wilson-Devinney code, the photometric elements were deduced from three sets of light curves. Based on all available eclipsing times, the orbital period changes were investigated. It is discovered that the (O-C) curve may show an existence of light-time effect due to an unseen third body, which was weakly identified by the photometric solution. The modulated period and amplitude of the cyclic variation are P_3_=71.2(+/-8.0)yr and A=0.0101(+/-0.0008)day, respectively. In the co-planar orbit with the binary system, the mass of the third body is M_3_=0.18(+/-0.02)M_{sun}_. The photometric results imply that EP Aur is an Algol-type binary with a mass ratio of q=0.831(+/-0.004). Its primary component almost fills its Roche lobe. Therefore, EP Aur may consist of a normal main-sequence star and a cool Roche-lobe filling subgiant, which may be undergoing rapid mass transfer.
- ID:
- ivo://CDS.VizieR/J/other/NewA/41.17
- Title:
- Time of minima of BX Peg
- Short Name:
- J/other/NewA/41.
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We presented BVRcIc light curves of BX Peg obtained by the Weihai Observatory 1.0m telescope of Shandong University. The W-D code was used to analyze the four color light curves, it is shown that BX Peg is a W-subtype shallow contact binary with a fill-out factor of f=14.6%. The asymmetric light curves were explained by a dark spot on the less massive hot component. A total of 328 times of minimum light were used to study the orbital period variation of BX Peg. We found that the orbital period of BX Peg was continuous decrease with a rate of dp/dt=-2.07x10^-7^d/yr superimposed on a cyclic oscillation with a period of 57.8yr. The secular period decrease should be caused by the angular momentum loss via magnetic stellar wind. The cyclic modulation is very likely to be produced by the light travel time effect due to a tertiary companion.
- ID:
- ivo://CDS.VizieR/J/other/JAVSO/38.183
- Title:
- Time of minima of eclipsing binaries
- Short Name:
- J/other/JAVSO/38
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This paper continues the publication of times of minima for eclipsing binary stars from observations reported to the AAVSO Eclipsing Binary section. Times of minima from observations made from September 2009 through February 2010 are presented.
- ID:
- ivo://CDS.VizieR/J/MNRAS/428/1656
- Title:
- Time of minima of HD 181068
- Short Name:
- J/MNRAS/428/1656
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- HD 181068 is the brighter of the two known triply eclipsing hierarchical triple stars in the Kepler field. It has been continuously observed for more than 2yr with the Kepler space telescope. Of the nine quarters of the data, three have been obtained in short-cadence mode, that is one point per 58.9s. Here we analyse this unique data set to determine absolute physical parameters (most importantly the masses and radii) and full orbital configuration using a sophisticated novel approach. We measure eclipse timing variations (ETVs), which are then combined with the single-lined radial velocity measurements to yield masses in a manner equivalent to double-lined spectroscopic binaries. We have also developed a new light-curve synthesis code that is used to model the triple, mutual eclipses and the effects of the changing tidal field on the stellar surface and the relativistic Doppler beaming. By combining the stellar masses from the ETV study with the simultaneous light-curve analysis we determine the absolute radii of the three stars. Our results indicate that the close and the wide subsystems revolve in almost exactly coplanar and prograde orbits. The newly determined parameters draw a consistent picture of the system with such details that have been beyond reach before.
