Orbital and physical parameters of eclipsing binaries from the ASAS catalogue -- XI. CHIRON investigation of long-period binaries
M. Ratajczak, R. K. Pawłaszek, K. G. Hełminiak, M. Konacki, P. Sybilski, S. K. Kozłowski, M. Litwicki, A. M. S. Smith, P. Mikołajczyk, D. R. Anderson, C. Hellier
备注：
20 pages, 9 images, 5 tables. Accepted for publication in MNRAS
We present the results of a spectroscopic campaign on eclipsing binaries with long orbital period (P = 20 - 75 d) carried out with the CHIRON spectrograph. Physical and orbital solutions for seven systems were derived from the V-band, and I-band ASAS, WASP, and TESS photometry, while radial velocities were calculated from high quality optical spectra using a two-dimensional cross-correlation technique. The atmospheric parameters of the stars have been determined from the separated spectra. Most of our targets are composed of evolved stars (sub-giants or red giants) but two systems show components in different phases of evolution and one possible merger. For four binaries the masses and radii of the components were obtained with precision better than 3%. These objects provide very valuable information on stellar evolution.
We report the identification of a new, long period detached eclipsing binary by the All-Sky Automated Survey for Supernovae (ASAS-SN). Combining V-band photometry from ASAS-SN, ASAS and KELT, we constructed a light curve spanning 2006-2018. ASASSN-V J192543.72+402619.0 is an eccentric detached eclipsing binary with an orbital period of $P\sim7.3$ yr, a minimum orbital eccentricity of $e_{min}\sim0.2$ and a primary eclipse lasting $\sim160$ d. We also detect a secondary eclipse that is $\sim 0.6$ mag shallower. Multi-band photometry suggests that the more luminous component of the binary is an …
For more than three years now we have been conducting a spectroscopic survey of detached eclipsing binaries (DEBs) from the All-Sky Automated Survey (ASAS) database. Thousands of high-resolution spectra of over 300 systems were secured, and used for radial velocity measurements and spectral analysis. In our sample we found a zoo of multiple systems, such as spectroscopic triples and quadruples, visual binaries with eclipsing components, and circumbinary low-mass companions, including sub-stellar-mass candidates
We present absolute physical and orbital parameters for three double-lined detached eclipsing binary systems from the All Sky Automated Survey (ASAS) catalogue with subgiant and giant components. These parameters were derived from archival V-band ASAS photometry and new radial velocities. The radial velocities were calculated from high quality optical spectra we obtained with the 8.2 m Subaru/HDS, ESO 3.6 m/HARPS, 1.9 m Radcliffe/GIRAFFE, CTIO 1.5 m/CHIRON, and 1.2 m Euler/CORALIE using the two-dimensional cross-correlation technique (TODCOR) and synthetic template spectra chosen for every sys…
We report the identification of the bright (V${\sim}13.3$ mag) star FY Sct as a long period detached eclipsing binary using a combined ASAS-SN and ASAS light curve spanning 2000-2018. The orbital period is P${\sim}2.57$ years and the primary eclipse lasts ${\sim}73$ days. The eclipse profile is suggestive of a disk eclipsing binary rather than a stellar component. We also detect ${\sim}0.4$ mag pulsations with a period of P${\sim78}$ d. The next eclipse begins on September, 28, 2018. Further photometric and spectroscopic observations are encouraged, particularly when the system is in eclipse.
Detached eclipsing binaries are the primary tool used to measure precise masses and radii of stars. In our previous paper estimating the parameters of more than 30,000 detached eclipsing binaries, we identified 766 eclipsing binaries with additional features in their All-Sky Automated Survey for Supernovae (ASAS-SN) and Transiting Exoplanet Survey Satellite (TESS) light curves. Here, we characterize these "extra-physics" systems, identifying eclipsing binaries with spotted stars, pulsating components, and candidate triple/quadruple systems. We use the Gaia, ATLAS, ZTF, and ASAS-SN variable sta…
The star ASAS J174600-2321.3 was found to exhibit peculiar photometric variability (conspicuous brightening of about 4 magnitudes (V), fast luminosity declines, intrinsic pulsations). It was rejected as an RCB candidate in recent investigations on spectroscopic grounds. We have collected and present all available data from public sky surveys, photometric catalogues, and the literature. From an analysis of these data, we have identified ASAS J174600-2321.3 as a long-period eclipsing binary (Porb = 1011.5 days). The primary star, which is probably a white dwarf, is currently in outburst and exhi…
We use ASAS V-band and ASAS-SN g-band observations to model the long-period detached eclipsing binary ASASSN-21co. ASAS observations show an eclipse of depth V ~ 0.6 mag in April of 2009. ASAS-SN g-band observations from March of 2021 show an eclipse of similar duration and depth, suggesting an orbital period of 11.9 years. We combine the g-band observations with additional BVRI photometry taken during the eclipse to model the eclipse using PHOEBE. We find that the system is best described by two M giants with a ratio of secondary radius to primary radius of ~0.61. Optical spectra taken during…
We present the first full orbital and physical analysis of HD 187669, recognized by the All-Sky Automated Survey (ASAS) as the eclipsing binary ASAS J195222-3233.7. We combined multi-band photometry from the ASAS and SuperWASP public archives and 0.41-m PROMPT robotic telescopes with our high-precision radial velocities from the HARPS spectrograph. Two different approaches were used for the analysis: 1) fitting to all data simultaneously with the WD code, and 2) analysing each light curve (with JKTEBOP) and RVs separately and combining the partial results at the end. This system also shows a t…
We present a catalog of 56 candidate intermediate mass eclipsing binary systems extracted from the 3rd data release of the All Sky Automated Survey. We gather pertinent observational data and derive orbital properties, including ephemerides, for these systems as a prelude to anticipated spectroscopic observations. We find that 37 of the 56, or ~66% of the systems are not identified in the Simbad Astronomical Database as known binaries. As a specific example, we show spectroscopic data obtained for the system HI Mon (B0 V + B0.5 V) observed at key orbital phases based on the computed ephemeris,…
Detached eclipsing binaries are a fundamental tool for measuring the physical parameters of stars that are effectively evolving in isolation. Starting from more than 40,000 eclipsing binary candidates identified by the All-Sky Automated Survey for Supernovae (ASAS-SN), we use PHOEBE to determine the sum of the fractional radii, the ratio of effective temperatures, the inclinations, and the eccentricities for 35,464 systems. We visually inspect all the light curve models to verify the model fits and examine the TESS light curves, when available, to select systems with evidence for additional ph…
We present a detailed light curve analysis of publicly available V band observations of 62 binary stars, mostly contact binaries, obtained by the All Sky Automated Survey (ASAS)-3 project between 2000 and 2009. Eclipsing binaries are important astronomical targets for determining the physical parameters of component stars from the geometry. They provide an independent direct method of measuring the radii of stars. We improved the ASAS determined periods, ephemeris and obtained the Fourier parameters from the phased light curves of these 62 stars. These Fourier parameters were used for prelimin…
The photometric and spectroscopic data for three double-lined detached eclipsing binaries were collected from the photometric and spectral surveys. The light and radial velocity curves of each binary system were simultaneously analyzed by using Wilson-Devinney (WD) code, and the absolute physical and orbital parameters of these binaries were derived. The masses of both components of ASASSN-V J063123.82+192341.9 were found to be $M_1 = 1.088 \pm 0.016$ and $M_2 = 0.883 \pm 0.016\ M_{\odot}$; and those of ASAS J011416+0426.4 were determined to be $M_1 = 0.934 \pm 0.046$ and $M_2 = 0.754 \pm 0.04…
Twin binaries were identified among the eclipsing binaries with $δ$>--30$^\circ$ listed in the ASAS catalog. In addition to the known twin binaries in the literature, 68 new systems have been identified, photometric and spectroscopic observations were done. Color, spectral type, temperature, ratio of radii and masses of the components have been derived and presented. Including 12 twin binary systems that exist in both ASAS and the catalogue of absolute parameters of detached eclipsing binary stars, a total of 80 twin detached binary systems have been statistically studied. A comparison of the …
Variable stars, or particularly eclipsing binaries, are very essential astronomical occurrence. Surveys are the backbone of astronomy, and many discoveries of variable stars are the results of surveys. All-Sky Automated Survey (ASAS) is one of the observing projects whose ultimate goal is photometric monitoring of variable stars. Since its first light in 1997, ASAS has collected 50,099 variable stars, with 11,076 eclipsing binaries among them. In the present work we focus on the period determination of the eclipsing binaries. Since the number of data points in each ASAS eclipsing binary light …
We report the discovery of a bright (V=11.6 mag) eclipsing hot subdwarf binary of spectral type B with a late main sequence companion from the All Sky Automated Survey (ASAS 102322-3737.0). Such systems are called HW Vir stars after the prototype. The lightcurve shows a grazing eclipse and a strong reflection effect. An orbital period of P=0.13927 d, an inclination of i=65.86°, a mass ratio q=0.34, a radial velocity semiamplitude K_1=81.0 kms^-1, and other parameters are derived from a combined spectroscopic and photometric analysis. The short period can only be explained by a common envelope …
Aims. We present the results of our detailed spectroscopic and photometric analysis of two previously unknown < 1 M{_\sun} detached eclipsing binaries: ASAS J045304-0700.4 and ASAS J082552-1622.8. Methods. With the HIgh Resolution Echelle Spectrometer (HIRES) on the Keck-I telescope, we obtained spectra of both objects covering large fractions of orbits of the systems. We also obtained V and I band photometry with the 1.0-m Elizabeth telescope of the South African Astronomical Observatory (SAAO). The orbital and physical parameters of the systems were derived with the PHOEBE and JKTEBOP codes.…
We present the orbital and physical parameters of a newly discovered low-mass detached eclipsing binary from the All-Sky Automated Survey (ASAS) database: ASAS J011328-3821.1 A - a member of a visual binary system with the secondary component separated by about 1.4 seconds of arc. The radial velocities were calculated from the high-resolution spectra obtained with the 1.9-m Radcliffe/GIRAFFE, 3.9-m AAT/UCLES and 3.0-m Shane/HamSpec telescopes/spectrographs on the basis of the TODCOR technique and positions of H_alpha emission lines. For the analysis we used V and I band photometry obtained wit…
We present spectroscopic and photometric solutions for three spotted systems with red giant components. Absolute physical and orbital parameters for these double-lined detached eclipsing binary stars are presented for the first time. These were derived from the V-, and I-band ASAS and WASP photometry, and new radial velocities calculated from high quality optical spectra we obtained with a wide range of spectrographs and using the two-dimensional cross-correlation technique (TODCOR). All of the investigated systems (ASAS J184949-1518.7, BQ Aqr, and V1207 Cen) show the differential evolutionary…
We have analyzed the double-lined eclipsing binary system ASAS J180057-2333.8 from the All Sky Automated Survey (ASAS) catalogue . We measure absolute physical and orbital parameters for this system based on archival $V$-band and $I$-band ASAS photometry, as well as on high-resolution spectroscopic data obtained with ESO 3.6m/HARPS and CORALIE spectrographs. The physical and orbital parameters of the system were derived with an accuracy of about 0.5 - 3%. The system is a very rare configuration of two bright well-detached giants of spectral types K1 and K4 and luminosity class II. The radii of…
We present a classification of the light curve morphologies of eclipsing binary systems observed by ASAS-SN based on their light curve images. The data of 16500 eclipsing systems having three different classes (detached Algol type, $β$ Lyr type, and W UMa type) are collected to construct their light curves. A deep learning algorithm containing the convolutional neural networks is employed on the images to achieve a satisfying classification. A code called ASEBCLASS is written in Python language, and it uses the TensorFlow platform through Keras API to employ the mathematical libraries in the t…
We present the results of our spectroscopic and photometric analysis of two newly discovered low-mass detached eclipsing binaries found in the All-Sky Automated Survey (ASAS) catalogue: ASAS J093814-0104.4 and ASAS J212954-5620.1. Using the GIRAFFE instrument on the 1.9-m Radcliffe telescope at SAAO and the UCLES spectrograph on the 3.9-m Anglo-Australian Telescope, we obtained high-resolution spectra of both objects and derived their radial velocities (RVs) at various orbital phases. The RVs of both objects were measured with the TODCOR technique using synthetic template spectra as references…
We explore the synergy between photometric and spectroscopic surveys by searching for periodic variable stars among the targets observed by the Apache Point Observatory Galactic Evolution Experiment (APOGEE) using photometry from the All-Sky Automated Survey for Supernovae (ASAS-SN). We identified 1924 periodic variables among more than 258000 APOGEE targets; 465 are new discoveries. We homogeneously classified 430 eclipsing and ellipsoidal binaries, 139 classical pulsators (Cepheids, RR Lyrae and delta Scuti), 719 long period variables (pulsating red giants) and 636 rotational variables. The …
We derive the absolute physical and orbital parameters for a sample of 18 detached eclipsing binaries from the \emph{All Sky Automated Survey} (ASAS) database based on the available photometry and our own radial velocity measurements. The radial velocities (RVs) are computed using spectra we collected with the 3.9-m Anglo-Australian Telescope and its \emph{University College London Echelle Spectrograph} and the 1.9-m SAAO Radcliffe telescope and its \emph{Grating Instrument for Radiation Analysis with a Fibre Fed Echelle}. In order to obtain as precise RVs as possible, most of the systems were…
The majority of cataclysmic variable (CV) stars contain a stochastic noise component in their light curves, commonly referred to as flickering. This can significantly affect the morphology of CV eclipses and increases the difficulty in obtaining accurate system parameters with reliable errors through eclipse modelling. Here we introduce a new approach to eclipse modelling, which models CV flickering with the help of Gaussian processes (GPs). A parameterised eclipse model - with an additional GP component - is simultaneously fit to 8 eclipses of the dwarf nova ASASSN-14ag and system parameters …
Photometric data from the ASAS - South (declination less than 29 deg) survey have been used for identification of bright stars located near the sources from the ROSAT All Sky Survey Bright Source Catalog (RBSC). In total 6028 stars brighter than 12.5 mag in I- or V -bands have been selected and analyzed for periodicity. Altogether 2302 variable stars have been found with periods ranging from 0.137 d to 193 d. Most of these stars have X-ray emission of coronal origin with a few cataclysmic binaries and early type stars with colliding winds. Whenever it was possible we collected data available i…
We report photometric and spectroscopic observations of the eclipsing SU UMa-type dwarf nova ASASSN-18aan. We observed the 2018 superoutburst with 2.3 mag brightening and found the orbital period ($P_{\rm orb}$) to be 0.149454(3) d, or 3.59 hr. This is longward of the period gap, establishing ASASSN-18aan as one of a small number of long-$P_{\rm orb}$ SU UMa-type dwarf novae. The estimated mass ratio, ($q=M_2/M_1 = 0.278(1)$), is almost identical to the upper limit of tidal instability by the 3:1 resonance. From eclipses, we found that the accretion disk at the onset of the superoutburst may r…
The Light-Time Effect (LTE) is observed whenever the distance between the observer and any kind of periodic event changes in time. The usual cause of this distance change is the reflex motion about the system's barycenter due to the gravitational influence of one or more additional bodies. We analyze 5032 eclipsing contact (EC) and detached (ED) binaries from the All Sky Automated Survey (ASAS) catalogue to detect variations in the times of eclipses which possible can be due to the LTE effect. To this end we use an approach known from the radio pulsar timing where a template radio pulse of a p…
Using the data from the public database of the All Sky Automated Survey ({\tt ASAS}) we performed the very first light curve analyses of the three eclipsing binary systems \astrobj{AO~Aqr}, \astrobj{CW~Aqr} and \astrobj{ASAS~012206-4924.7}. The physical parameters of the systems were determined by the {\tt PHOEBE} software. From an analysis of the ASAS data it was concluded that AO~Aqr was found to be a contact binary system while CW~Aqr and ASAS~012206-4924.7 were found to be near--contact and detached binaries, respectively. Finally, the locations of the components, corresponding to the esti…
We present results of the analysis of light and radial velocity (RV) curves of eight detached eclipsing binaries observed by the All-Sky Automated Survey, which we have followed up with high-resolution spectroscopy, and were later observed by the $Kepler$ satellite as part of the $K2$ mission. The RV measurements came from spectra obtained with OAO-188/HIDES, MPG-2.2m/FEROS, SMARTS 1.5m/CHIRON, Euler/CORALIE, ESO-3.6m/HARPS, and OHP-1.93/ELODIE instruments. The $K2$ time-series photometry was analyzed with the JKTEBOP code, with out-of-eclipse modulations of different origin taken into account…
Brightening of Hen 3-860, previously classified as an H$α$ emitter, was detected by the ASAS-SN survey at the end of the year 2016. We have obtained the first spectroscopic observations of the transient and supplemented them with photometric data from the DASCH archive of astronomical plates, ASAS and ASAS-SN surveys. Based on the results of our analysis, we can classify the object as a classical symbiotic star of the infrared type S, consisting of an M2-3 giant with $T_{\rm g}$ $\sim$ 3 550 K, a radius $R_{\rm g}\sim$ 60 - 75 R$_{\odot}$, and a luminosity $L_{\rm g}\sim$ 540 - 760 L$_{\odot}$…
Analyzing available photometry from Hipparcos, ASAS, Pi of the sky and Super WASP, we found that the system SY Phe is a detached eclipsing binary with similar components and orbital period about 5.27089 days. It has a slightly eccentric orbit, however the apsidal motion is probably very slow. The system undergoes an additional photometric variation on longer time scales superimposed on the eclipsing light curve. It also contains one distant component, hence the third light was also considered.
We present results of the combined photometric and spectroscopic analysis of three detached eclipsing binaries, which secondary components are not visible or very hard to identify in the optical spectra - ASAS J052743-0359.7, ASAS J065134-2211.5, and ASAS J073507-0905.7. The first one is a known visual binary ADS 4022, and we found that it is a quadruple system, composed of two spectroscopic binaries, one of which shows eclipses. None of the systems was previously recognized as a spectroscopic binary. We collected a number of high-resolution optical and IR spectra to calculate the radial veloc…
Motivated by the detection of a recent outburst of the massive luminous blue variable LMC-R71, which reached an absolute magnitude M_V = -9.3 mag, we undertook a systematic study of the optical variability of 1268 massive stars in the Large Magellanic Cloud, using a recent catalog by Bonanos et al. (2009) as the input. The ASAS All Star Catalog (Pojmanski 2002) provided well-sampled light curves of these bright stars spanning 10 years. Combining the two catalogs resulted in 599 matches, on which we performed a variability search. We identified 117 variable stars, 38 of which were not known bef…
We present the orbital and physical parameters of the detached eclipsing binary V1200~Centauri (ASAS~J135218-3837.3) from the analysis of spectroscopic observations and light curves from the \textit{All Sky Automated Survey} (ASAS) and SuperWASP database. The radial velocities were computed from the high-resolution spectra obtained with the OUC 50-cm telescope and PUCHEROS spectrograph and with 1.2m Euler telescope and CORALIE spectrograph using the cross-correlation technique \textsc{todcor}. We found that the absolute parameters of the system are $M_1= 1.394\pm 0.030$ M$_\odot$, $M_2= 0.866\…
The magnetic Ap or CP2 stars are natural atomic and magnetic laboratories and ideal testing grounds for the evaluation of model atmospheres. CP2 stars exhibiting photometric variability are traditionally referred to as alpha2 Canum Venaticorum (ACV) variables. Strictly periodic changes are observed in the spectra and brightness of these stars, which allow the derivation of rotational periods. Related to this group of objects are the He-weak (CP4) and He-rich stars, some of which are also known to undergo brightness changes due to rotational modulation. Increasing the sample size of known rotat…
Photometric observations in V and I bands and low-dispersion spectra of ten ultrashort-period binaries (NSVS 2175434, NSVS 2607629, NSVS 5038135, NSVS 8040227, NSVS 9747584, NSVS 4876238, ASAS 071829-0336.7, SWASP 074658.62+224448.5, NSVS 2729229, NSVS 10632802) are presented. One of them, NSVS 2729229, is newly discovered target. The results from modeling and analysis of our observations revealed that: (i) Eight targets have overcontact configurations with considerable fillout factor (up to 0.5) while NSVS 4876238 and ASAS 0718-03 have almost contact configurations; (ii) NSVS 4876238 is rare …
The majority of non-merging stellar mass black holes are discovered by observing high energy emission from accretion processes. Here we pursue the large, but still mostly unstudied population of non-interacting black holes and neutron stars by searching for the tidally-induced ellipsoidal variability of their stellar companions. We start from a sample of about 200,000 rotational variables, semi-regular variables, and eclipsing binary stars from the All-Sky Automated Survey for Supernovae (ASAS-SN). We use a $χ^2$ ratio test followed by visual inspection to identify 369 candidates for ellipsoid…
The All-Sky Automated Survey for Supernovae (ASAS-SN) provides long baseline (${\sim}4$ yrs) light curves for sources brighter than V$\lesssim17$ mag across the whole sky. As part of our effort to characterize the variability of all the stellar sources visible in ASAS-SN, we have produced ${\sim}30.1$ million V-band light curves for sources in the southern hemisphere using the APASS DR9 catalog as our input source list. We have systematically searched these sources for variability using a pipeline based on random forest classifiers. We have identified ${\sim} 220,000$ variables, including ${\s…
We present a CCD photometric study of the star with ASAS ID 134738 + 0410.1 using V band observations obtained from the $IUCAA$ Girawali Observatory (IGO) 2-metre telescope, India. The star was selected from the $δ$ Scuti database of All Sky Automated Survey (ASAS) (Pojmanski 2002). Our analysis reveals that the star is not a $δ$ Scuti variable but is in fact a W UMa type contact binary with an orbital period of 0.2853067 day. Two new times of primary and secondary minima were determined from the observed data. A preliminary solution obtained using the Wilson-Devinney light curve modelling tec…
Eclipsing binaries are important tools for studying stellar evolution and stellar interiors. Their accurate fundamental parameters are used to test evolutionary models, and systems showing apsidal motion can also be used to test the model's internal structure predictions. For this purpose, we present a photometric and spectroscopic analysis of the eclipsing binary BW Aquarii, an evolved F-type binary with slow apsidal motion. We model the K2 C3 light curve using the Eclipsing Light Curve code to determine several orbital and stellar parameters, as well as measure the eclipse times to determine…
We present the first results from Citizen ASAS-SN, a citizen science project for the All-Sky Automated Survey for Supernovae (ASAS-SN) hosted on the Zooniverse platform. Citizen ASAS-SN utilizes the newer, deeper, higher cadence ASAS-SN $g$-band data and tasks volunteers to classify periodic variable star candidates based on their phased light curves. We started from 40,640 new variable candidates from an input list of ${\sim} 7.4$ million stars with $δ< -60^\circ$ and the volunteers identified 10,420 new discoveries which they classified as 4,234 pulsating variables, 3,132 rotational variable…
Next-generation synoptic photometric surveys will yield unprecedented (for the astronomical community) volumes of data and the processes of discovery and rare-object identification are, by necessity, becoming more autonomous. Such autonomous searches can be used to find objects of interest applicable to a wide range of outstanding problems in astronomy, and in this paper we present the methods and results of a largely autonomous search for highly eccentric detached eclipsing binary systems in the Machine-learned ASAS Classification Catalog. 106 detached eclipsing binaries with eccentricities g…
We present a detailed photometric and spectroscopic analysis of DD CMa, based on published survey photometry and new spectroscopic data. We find an improved orbital period of $P_\mathrm{o}= 2.0084530 \pm 0.0000006 ~\mathrm{d}$. Our spectra reveal H$β$ and H$α$ absorptions with weak emission shoulders and we also find color excess in the WISE multiband photometry, interpreted as signatures of circumstellar matter. We model the $V$-band orbital light curve derived from the ASAS and ASAS-SN surveys, assuming a semidetached configuration and using the mass ratio and temperature of the hotter star …
Six new doubly eclipsing quadruples in a 2+2 architecture
Charles University, Faculty of Mathematics and Physics, Astronomical Institute（查理大学数学物理学院天文研究所）；Hvězdárna Jaroslava Trnky ve Slaném（斯拉尼扬罗斯拉夫·特恩基天文台）；Variable Star and Exoplanet Section, Czech Astronomical Society（捷克天文学会变星与系外行星学部）；FZU - Institute of Physics of the Czech Academy of Sciences（捷克科学院物理研究所）；Research Centre for Theoretical Physics and Astrophysics, Institute of Physics, Silesian University in Opava（奥帕瓦西里西亚大学物理研究所理论物理与天体物理研究中心）；Observatory Mladá Boleslav（姆拉达博莱斯拉夫天文台）；Department of Physics and Astronomy, University of Texas Rio Grande Valley（德克萨斯大学里奥格兰德河谷分校物理与天文学系）；Instituto de Astrofísica de Canarias（加那利群岛天体物理研究所）；Astronomical Institute, Academy of Sciences（科学院天文研究所）
The ages of the components in very short period pre-main sequence (PMS) binaries are essential to an understanding of their formation. We considered a sample of 7 PMS eclipsing binaries (EBs) with ages 1 to 6.3 MY and component masses 0.2 to 1.4 Msun The very high precision with which their masses and radii have been measured, and the capability provided by the {\it Modules for Experiments in Stellar Astrophysics (MESA)} to calculate their evolutionary tracks at exactly the measured masses, allows the determination of age differences of the components independent of their luminosities and effe…
We present new spectroscopic observations of the early type, double-lined eclipsing binary V1441\,Aql. The radial velocities and the available photometric data obtained by $ASAS$ is analysed for deriving the parameters of the components. The components of V1441\,Aql are shown to be a B3\,IV primary with a mass M$_p$=8.02$\pm$0.51 M$_{\odot}$ and radius R$_p$=7.33$\pm$0.19 R$_{\odot}$ and a B9 III secondary with a mass M$_s$=1.92$\pm$0.14 M$_{\odot}$ and radius R$_s$=4.22$\pm$0.11 R$_{\odot}$. Our analyses show that V1441\,Aql is a double-contact system with rapidly rotating components. Based o…
We calculated physical and orbital properties for 2M06464003+0109157, a 1.06 day eclipsing double lined spectroscopic binary. We modelled the system's ASAS-SN and TESS light curves, measuring the system's inclination and radii of each component. Extracting radial velocities for each component from 6 SDSS/APOGEE spectra, we measured the system's mass ratio and performed a full orbital fit. Our analysis indicates that 2M06464003+0109157 has components with nearly equal masses ($m_1/m_2 =0.99 \pm 0.01$; $M_1{_,}{_2} = 0.57 \pm 0.015$ M$_\odot$) and comparable radii ($R_1 = 0.66 \pm 0.05$ R$_\odot…
In this work we report the discovery and analysis of three new triply eclipsing triple star systems found with the TESS mission during its observations of the northern skies: TICs 193993801, 388459317, and 52041148. We utilized the TESS precision photometry of the binary eclipses and third-body eclipsing events, ground-based archival and follow-up photometric data, eclipse timing variations, archival spectral energy distributions, as well as theoretical evolution tracks in a joint photodynamical analysis to deduce the system masses and orbital parameters of both the inner and outer orbits. In …
We characterize an all-sky catalog of ${\sim} 8,400$ $δ$ Scuti variables in ASAS-SN, which includes ${\sim} 3,300$ new discoveries. Using distances from \textit{Gaia} DR2, we derive period-luminosity relationships (PLRs) for both the fundamental mode and overtone pulsators in the $W_{JK}$, $V$, Gaia DR2 $G$, $J$, $H$, $K_s$ and $W_1$ bands. We find that the overtone pulsators have a dominant overtone mode, with many sources pulsating in the second overtone or higher order modes. The fundamental mode pulsators have metallicity dependent periods, with $\log_{10} (\rm P){\sim}-1.1$ for $\rm [Fe/H…
We present a new analysis of the multiple star V1200 Centauri based on the most recent observations for this system. We used the photometric observations from the Solaris network and the TESS telescope, combined with the new radial velocities from the CHIRON spectrograph and those published in the literature. We confirmed that V1200 Cen consists of a 2.5-day eclipsing binary orbited by a third body. We derived the parameters of the eclipsing components, which are $M_{Aa} = 1.393\pm0.018\,$M$_\odot$, $R_{Aa} = 1.407\pm0.014\,$R$_\odot$ and $T_{{\rm eff},Aa} = 6\,588\pm58\,$K for the primary, an…
Magnetic chemically peculiar (mCP) stars allow the investigation of such diverse phenomena as atomic diffusion, magnetic fields and stellar rotation. The aim of the present investigation is to enhance our knowledge of the rotational properties of mCP stars by increasing the sample of objects with accurately determined rotational periods. To this end, archival photometric time-series data from the ASAS-3, KELT and MASCARA surveys were employed to improve existing rotational period information and derive rotational periods for mCP stars hitherto not known to be photometric variables. Our final s…
ASAS J174406+2446.8 was originally found as a $δ$ Scuti-type pulsating star with the period P=0.189068 $days$ by ASAS survey. However, the LAMOST stellar parameters reveal that it is far beyond the red edge of pulsational instability strip on the $\log g-T$ diagram of $δ$ Scuti pulsating stars. To understand the physical properties of the variable star, we observed it by the 1.0-m Cassegrain reflecting telescope at Yunnan Observatories. Multi-color light curves in B, V, R$_{c}$ and I$_{c}$ bands were obtained and are analyzed by using the W-D program. It is found that this variable star is a s…
