Recently, a new radio millisecond pulsar(MSP) J1740-5340B, hosted in the globular cluster(GC) NGC 6397,was reported with a 5.78 ms spin period in an eclipsing binary system with a 1.97 days orbital period. Based on a ...Recently, a new radio millisecond pulsar(MSP) J1740-5340B, hosted in the globular cluster(GC) NGC 6397,was reported with a 5.78 ms spin period in an eclipsing binary system with a 1.97 days orbital period. Based on a modified radio ephemeris updated by tool tempo2, we analyze the ~15 yr γ-ray data obtained from the Large Area Telescope on board the Fermi Gamma-ray Space Telescope and detect PSR J1740-5340B's γ-ray pulsation at a confidence level of ~4σ with a weighted H-test value of ~26. By performing a phase-resolved analysis, the γ-ray luminosity in on-pulse interval of PSR J1740-5340B is L_(γ)~ 3.8 × 10^(33) erg s^(-1) using NGC 6397's distance of 2.48 kpc. And γ-rays from the on-pulse part of PSR J1740-5340B contribute ~90% of the total observed γ-ray emissions from NGC 6397. No significant γ-ray pulsation of another MSP J1740-5340A in the GC is detected.Considering that the previous four cases of MSPs in GCs, more data in γ-ray, X-ray, and radio are encouraged to finally confirm the γ-ray emissions from MSP J1740-5340B, especially starving for a precise ephemeris.展开更多
Open clusters are the basic building blocks that serve as a laboratory for the study of young stellar populations in the Milky Way.Variable stars in open clusters provide a unique way to accurately probe the internal ...Open clusters are the basic building blocks that serve as a laboratory for the study of young stellar populations in the Milky Way.Variable stars in open clusters provide a unique way to accurately probe the internal structure,temporal and dynamical evolutionary stages of individual stars and the host cluster.The most powerful tool for such studies is time-domain photometric observations.This paper follows the route of our previous work,concentrating on a photometric search for variable stars in NGC 884.The target cluster is the companion of NGC869,forming the well-known double cluster system that is gravitationally bound.From the observation run in 2016 November,a total of 9247 B-band CCD images and 8218Ⅴ-band CCD images were obtained.We detected a total of 15 stars with variability in visual brightness,including five Be stars,three eclipsing binaries,and seven of unknown types.Two new variable stars were discovered in this work.We also compared the variable star content of NGC 884 with its companion NGC 869.展开更多
The events from 157 globular clusters(GCs)are analyzed by using 12 yr long-term Pass 8 data from Fermi Large Area Telescope.Besides the 34 GCs reported in previous literatures,four additional GCs(ESO 452-SC11,NGC6380,...The events from 157 globular clusters(GCs)are analyzed by using 12 yr long-term Pass 8 data from Fermi Large Area Telescope.Besides the 34 GCs reported in previous literatures,four additional GCs(ESO 452-SC11,NGC6380,Palomar 6 and UKS 1)in the Milky Way are detected as gamma-ray GC candidates.Especially for UKS 1,these are known as the faintest GCs in long-wavelength bands.Further data analysis has been performed for the four GCs.While no pulsars are determined in radio and/or X-ray wavelengths so far,their gamma-ray pulsation emissions are not found,and no significant gamma-ray flux variability is detected.The numbers of MSPs within the four GCs are estimated based on the assumption that the MSPs within each GC emit similar amounts of gamma-rays.The gamma-ray results reported here could help us better understand the nature of gamma-ray emission origins for GCs.展开更多
In this paper we study some van den Bergh open clusters combining photometry and astrometry. A model which analyses the proper motion distribution and the stellar density is applied to find the kinematic parameters an...In this paper we study some van den Bergh open clusters combining photometry and astrometry. A model which analyses the proper motion distribution and the stellar density is applied to find the kinematic parameters and stellar membership in the region of the open clusters vdB92, vdB146 (NGC 7129) and vdB150. The astrometric data are obtained from UCAC4 catalogue. The centre coordinates, the components of mean proper motion, the angular diameter and the astrometric members are reported, taking the following values: for vdB92: α=105.97281°±0.13113°, δ=−11.57814°±0.10575°,?μαcosδ=−3.46±0.19mas/yr,μδ=1.27±0.19mas/yr, 34', 60 members;for vdB146: α=325.78423°±0.15297°, δ=66.13575°±0.02907°, μαcosδ=−2.71±0.25mas/yr, μδ=−3.32±0.25mas/yr, 9', 5 members;and for vdB150: α=332.22519°±0.06074°, δ=73.40232°±0.0.07789°, μαcosδ=3.07±0.90mas/yr, μδ=4.65±0.90mas/yr, 15', 7 members. The incidence of the proper motion errors in the determination of the cluster parameters and of the stellar membership is analysed and it is found that they do not significantly change. We finally compare the astrometric members with the photometric ones given in the literature.展开更多
This work presents the charge-coupled device(CCD)photometric survey of the old open cluster NGC 188.Timeseries V-band photometric observations were conducted for ten nights in 2017 January using the Nanshan Onemeter W...This work presents the charge-coupled device(CCD)photometric survey of the old open cluster NGC 188.Timeseries V-band photometric observations were conducted for ten nights in 2017 January using the Nanshan Onemeter Wide-field Telescope to search for variable stars in the field of the cluster.A total of 25 variable stars,including one new variable star,were detected in the target field.Among the detected variables,16 are cluster member stars,and the others are identified as field stars.The periods,radial velocities,effective temperatures,and classifications of the detected variables are discussed in this work.Most of the stars’effective temperatures are between 4200 and 6600 K,indicating their spectral types are G or K.The newly discovered variable is probably a W UMa system.In this study,a known cluster variable star(V21=V0769 Cep)is classified as an EA-type variable star based on the presence of an 0.5 mag eclipse in its light curve.展开更多
NGC 1266 is a lenticular galaxy(S0)hosting an active galactic nucleus(AGN),and known to contain a large amount of shocked gas.We compare the luminosity ratio of mid-J CO lines to IR continuum with star-forming galaxie...NGC 1266 is a lenticular galaxy(S0)hosting an active galactic nucleus(AGN),and known to contain a large amount of shocked gas.We compare the luminosity ratio of mid-J CO lines to IR continuum with star-forming galaxies(SFGs),and then model the CO spectral line energy distribution(SLED).We confirm that in the mid-and high-J regions(J_(up)=4-13),the C-type shock(v_(s)=25 km s^(-1),n_(H)=5×10^(4)cm^(-3))can reproduce the CO observations well.The galaxy spectral energy distribution(SED)is constructed and modeled by the code X-CIGALE and obtains a set of physical parameters including the star formation rate(SFR,1.17±0.47 M_(⊙)yr^(-1)).Also,our work provides SFR derivation of[C II]from the neutral hydrogen regions only(1.38±0.14 M_(⊙)yr^(-1)).Previous studies have illusive conclusions on the AGN or starburst nature of the NGC 1266 nucleus.Our SED model shows that the hidden AGN in the system is intrinsically low-luminosity,consequently the infrared luminosity of the AGN does not reach the expected level.Archival data from Nu STAR hard X-ray observations in the 3-79 keV band shows a marginal detection,disfavoring presence of an obscured luminous AGN and implying that a compact starburst is more likely dominant for the NGC 1266 nucleus.展开更多
As groups of coeval stars born from the same molecular cloud,an open cluster(OC)is an ideal laboratory for studying the structure and dynamical evolution of the Milky Way.The release of high-precision Gaia Early Data ...As groups of coeval stars born from the same molecular cloud,an open cluster(OC)is an ideal laboratory for studying the structure and dynamical evolution of the Milky Way.The release of high-precision Gaia Early Data Release 3(Gaia EDR3)and modern machine-learning methods offer unprecedented opportunities to identify OCs.In this study,we extended conventional HDBSCAN(e-HDBSCAN)for searching for new OCs in Gaia EDR3.A pipeline was developed based on the parallel computing technique to blindly search for OCs from Gaia EDR3within Galactic latitudes∣b∣<25°.As a result,we obtained 3787 star clusters,of which 83 new OCs were reported after cross-match and visual inspection.At the same time,the main star cluster parameters are estimated by color-magnitude diagram fitting.The study significantly increases the sample size and physical parameters of OCs in the catalog of OCs.It shows the incompleteness of the census of OCs across our Galaxy.展开更多
利用疏散星团NGC 188所在天区的1046颗恒星样本的高精度3维(3D)运动学数据(自行和视向速度)测试了DBSCAN(Density-Based Spatial Clustering of Applications with Noise)聚类算法的成员判定效果.为了避免自行和视向速度的单位不一致带...利用疏散星团NGC 188所在天区的1046颗恒星样本的高精度3维(3D)运动学数据(自行和视向速度)测试了DBSCAN(Density-Based Spatial Clustering of Applications with Noise)聚类算法的成员判定效果.为了避免自行和视向速度的单位不一致带来的影响,在数据预处理阶段将3个分量的数据统一标准化至[0,1]区间.利用第k个最近邻点距离方法分析了1046颗恒星样本在标准化无量纲3D速度空间的分布特征,再根据第k个最近邻点距离随k值的变化趋势确定了DBSCAN聚类算法的输入参数(Eps,MinPts),最后利用DBSCAN聚类算法分离出497颗3D运动学成员星.分析结果表明得到的3D运动学成员星是可靠的.展开更多
This work presents a time-series photometric variability survey of the young open cluster NGC 869.More than 13000 CCD frames in the BV filters were collected on 19 nights between 2014 November 6 and 2014 December 24.I...This work presents a time-series photometric variability survey of the young open cluster NGC 869.More than 13000 CCD frames in the BV filters were collected on 19 nights between 2014 November 6 and 2014 December 24.In a 20’×20’field centered on the cluster,we detected a total of 28 stars showing photometric variability,12 of which are new discoveries.The classifications and memberships of the variable stars are discussed according to the behaviors and periods of the light curves as well as their positions on the H-R diagram.These results conclude that 22 variable stars are probable members of the cluster while six other stars belong to the field star population.They are categorized as 18 pulsating variable stars(fourβCep,seven SPB,oneβCep/SPB,four Be stars,and twoδSct/γDor candidates),seven eclipsing binaries(five EA and two EB)and three unknown type stars.展开更多
We present the first CCD photometric observations of open cluster NGC 744, as part of the 50 BiN Open Cluster Survey. The color-magnitude diagrams of this cluster were derived from absolute BV RI photometry on a good ...We present the first CCD photometric observations of open cluster NGC 744, as part of the 50 BiN Open Cluster Survey. The color-magnitude diagrams of this cluster were derived from absolute BV RI photometry on a good photometric night. A brief isochrone fitting gives a distance modulus of(m-M)V= 11.58±0.2 and a reddening of E(B-V) = 0.35±0.05 with an age of log t = 8.30±0.05.By carefully examining the BV time-series data, we discovered four new variable stars in a 20′×20′field around the cluster. We classified them as three eclipsing binary stars and one δ Scuti pulsating star,mainly based on the light-curve shape, the detected periods and the positions on the color-magnitude diagrams.展开更多
This paper presents Charge-Coupled Device time-series photometric observations of the open cluster NGC 1582 and its surrounding field with Johnson B,V and R filters by using the Nanshan 1 m telescope administered by X...This paper presents Charge-Coupled Device time-series photometric observations of the open cluster NGC 1582 and its surrounding field with Johnson B,V and R filters by using the Nanshan 1 m telescope administered by Xinjiang Astronomical Observatory.19 variable stars and three variable candidates were detected in a 45′×48.75′ field around the cluster.12 of the variable stars are newly-discovered variable objects.The physical properties,classifications and memberships of these 22 objects are studied through their light curves,their positions on the color-magnitude diagram and with archival data from the Naval Observatory Merged Astrometric Dataset.Among these objects,five are eclipsing binary systems,six are pulsating variable stars including one known S Scuti star and one newly-discovered RR Lyrae star.The distance to the RR Lyrae star is estimated to be 7.9 ± 0.3 kpc,indicating that the star is located far behind the cluster.Four variable stars are probable members of the cluster,and 13 of the 22 objects are confirmed to be field stars.展开更多
We present the results of a time-series CCD photometric survey ofvariable stars in the field of the open cluster NGC 7789. In a field of about onedegree centering on the cluster, a total of 28 new variable stars are d...We present the results of a time-series CCD photometric survey ofvariable stars in the field of the open cluster NGC 7789. In a field of about onedegree centering on the cluster, a total of 28 new variable stars are discovered(14 W UMa systems, nine EA-type eclipsing binaries, one RR Lyr star, and fourunclassified). In addition, we recovered 11 old variables previously discovered byother authors. Preliminary parameters are given for some of these variables.展开更多
基金supported in part by the National Natural Science Foundation of China Nos. 12163006 and 12233006the Basic Research Program of Yunnan Province No. 202201AT070137+1 种基金the joint foundation of Department of Science and Technology of Yunnan Province and Yunnan University No. 202201BF070001-020support by the Xingdian Talent Support Plan-Youth Project。
文摘Recently, a new radio millisecond pulsar(MSP) J1740-5340B, hosted in the globular cluster(GC) NGC 6397,was reported with a 5.78 ms spin period in an eclipsing binary system with a 1.97 days orbital period. Based on a modified radio ephemeris updated by tool tempo2, we analyze the ~15 yr γ-ray data obtained from the Large Area Telescope on board the Fermi Gamma-ray Space Telescope and detect PSR J1740-5340B's γ-ray pulsation at a confidence level of ~4σ with a weighted H-test value of ~26. By performing a phase-resolved analysis, the γ-ray luminosity in on-pulse interval of PSR J1740-5340B is L_(γ)~ 3.8 × 10^(33) erg s^(-1) using NGC 6397's distance of 2.48 kpc. And γ-rays from the on-pulse part of PSR J1740-5340B contribute ~90% of the total observed γ-ray emissions from NGC 6397. No significant γ-ray pulsation of another MSP J1740-5340A in the GC is detected.Considering that the previous four cases of MSPs in GCs, more data in γ-ray, X-ray, and radio are encouraged to finally confirm the γ-ray emissions from MSP J1740-5340B, especially starving for a precise ephemeris.
基金the National Natural Science Foundation of China(NSFC)through grants 12003022,12373035,12233009 and 12173047support from the Youth Innovation Promotion Association of the CAS(grant No.2022055)。
文摘Open clusters are the basic building blocks that serve as a laboratory for the study of young stellar populations in the Milky Way.Variable stars in open clusters provide a unique way to accurately probe the internal structure,temporal and dynamical evolutionary stages of individual stars and the host cluster.The most powerful tool for such studies is time-domain photometric observations.This paper follows the route of our previous work,concentrating on a photometric search for variable stars in NGC 884.The target cluster is the companion of NGC869,forming the well-known double cluster system that is gravitationally bound.From the observation run in 2016 November,a total of 9247 B-band CCD images and 8218Ⅴ-band CCD images were obtained.We detected a total of 15 stars with variability in visual brightness,including five Be stars,three eclipsing binaries,and seven of unknown types.Two new variable stars were discovered in this work.We also compared the variable star content of NGC 884 with its companion NGC 869.
基金supported in part by the National Key R&D Program of China under Grant No.2018YFA0404204the National Natural Science Foundation of China(NSFC,Grant No.12163006)+1 种基金the Basic Research Program of Yunnan Province No.202101AT070394the Joint Foundation of Department of Science and Technology of Yunnan Province and Yunnan University(2018FY001(-003))。
文摘The events from 157 globular clusters(GCs)are analyzed by using 12 yr long-term Pass 8 data from Fermi Large Area Telescope.Besides the 34 GCs reported in previous literatures,four additional GCs(ESO 452-SC11,NGC6380,Palomar 6 and UKS 1)in the Milky Way are detected as gamma-ray GC candidates.Especially for UKS 1,these are known as the faintest GCs in long-wavelength bands.Further data analysis has been performed for the four GCs.While no pulsars are determined in radio and/or X-ray wavelengths so far,their gamma-ray pulsation emissions are not found,and no significant gamma-ray flux variability is detected.The numbers of MSPs within the four GCs are estimated based on the assumption that the MSPs within each GC emit similar amounts of gamma-rays.The gamma-ray results reported here could help us better understand the nature of gamma-ray emission origins for GCs.
文摘In this paper we study some van den Bergh open clusters combining photometry and astrometry. A model which analyses the proper motion distribution and the stellar density is applied to find the kinematic parameters and stellar membership in the region of the open clusters vdB92, vdB146 (NGC 7129) and vdB150. The astrometric data are obtained from UCAC4 catalogue. The centre coordinates, the components of mean proper motion, the angular diameter and the astrometric members are reported, taking the following values: for vdB92: α=105.97281°±0.13113°, δ=−11.57814°±0.10575°,?μαcosδ=−3.46±0.19mas/yr,μδ=1.27±0.19mas/yr, 34', 60 members;for vdB146: α=325.78423°±0.15297°, δ=66.13575°±0.02907°, μαcosδ=−2.71±0.25mas/yr, μδ=−3.32±0.25mas/yr, 9', 5 members;and for vdB150: α=332.22519°±0.06074°, δ=73.40232°±0.0.07789°, μαcosδ=3.07±0.90mas/yr, μδ=4.65±0.90mas/yr, 15', 7 members. The incidence of the proper motion errors in the determination of the cluster parameters and of the stellar membership is analysed and it is found that they do not significantly change. We finally compare the astrometric members with the photometric ones given in the literature.
基金the Resource sharing platform construction project of Xinjiang Uygur Autonomous Region(No.PT2306)the Chinese Academy of Sciences(CAS)“Light of West China”Program(No.2020-XBQNXZ-016,2022-XBQNXZ-016)。
文摘This work presents the charge-coupled device(CCD)photometric survey of the old open cluster NGC 188.Timeseries V-band photometric observations were conducted for ten nights in 2017 January using the Nanshan Onemeter Wide-field Telescope to search for variable stars in the field of the cluster.A total of 25 variable stars,including one new variable star,were detected in the target field.Among the detected variables,16 are cluster member stars,and the others are identified as field stars.The periods,radial velocities,effective temperatures,and classifications of the detected variables are discussed in this work.Most of the stars’effective temperatures are between 4200 and 6600 K,indicating their spectral types are G or K.The newly discovered variable is probably a W UMa system.In this study,a known cluster variable star(V21=V0769 Cep)is classified as an EA-type variable star based on the presence of an 0.5 mag eclipse in its light curve.
基金supported by the National Natural Science Foundation of China(NSFC Grant Nos.12033004,U1831205,12173079 and 12221003)the science research grants from the China Manned Space Project with Nos.CMS-CSST-2021A06 and CMS-CSST-2021-B02。
文摘NGC 1266 is a lenticular galaxy(S0)hosting an active galactic nucleus(AGN),and known to contain a large amount of shocked gas.We compare the luminosity ratio of mid-J CO lines to IR continuum with star-forming galaxies(SFGs),and then model the CO spectral line energy distribution(SLED).We confirm that in the mid-and high-J regions(J_(up)=4-13),the C-type shock(v_(s)=25 km s^(-1),n_(H)=5×10^(4)cm^(-3))can reproduce the CO observations well.The galaxy spectral energy distribution(SED)is constructed and modeled by the code X-CIGALE and obtains a set of physical parameters including the star formation rate(SFR,1.17±0.47 M_(⊙)yr^(-1)).Also,our work provides SFR derivation of[C II]from the neutral hydrogen regions only(1.38±0.14 M_(⊙)yr^(-1)).Previous studies have illusive conclusions on the AGN or starburst nature of the NGC 1266 nucleus.Our SED model shows that the hidden AGN in the system is intrinsically low-luminosity,consequently the infrared luminosity of the AGN does not reach the expected level.Archival data from Nu STAR hard X-ray observations in the 3-79 keV band shows a marginal detection,disfavoring presence of an obscured luminous AGN and implying that a compact starburst is more likely dominant for the NGC 1266 nucleus.
基金supported by the National SKA Program of China No.2020SKA0110300Joint Research Fund in Astronomy(U1831204)under cooperative agreement between the National Natural Science Foundation of China(NSFC)+5 种基金the Chinese Academy of Sciences(CAS)the National Key Research and Development Program of China(2018YFA0404603)the NSFC(Nos.11863002 and 11961141001)supported by the Yunnan Academician Workstation of Wang Jingxiu(No.202005AF150025)China Manned Space Project with NO.CMS-CSST-2021-A08Sino-German Cooperation Project(No.GZ 1284)。
文摘As groups of coeval stars born from the same molecular cloud,an open cluster(OC)is an ideal laboratory for studying the structure and dynamical evolution of the Milky Way.The release of high-precision Gaia Early Data Release 3(Gaia EDR3)and modern machine-learning methods offer unprecedented opportunities to identify OCs.In this study,we extended conventional HDBSCAN(e-HDBSCAN)for searching for new OCs in Gaia EDR3.A pipeline was developed based on the parallel computing technique to blindly search for OCs from Gaia EDR3within Galactic latitudes∣b∣<25°.As a result,we obtained 3787 star clusters,of which 83 new OCs were reported after cross-match and visual inspection.At the same time,the main star cluster parameters are estimated by color-magnitude diagram fitting.The study significantly increases the sample size and physical parameters of OCs in the catalog of OCs.It shows the incompleteness of the census of OCs across our Galaxy.
文摘利用疏散星团NGC 188所在天区的1046颗恒星样本的高精度3维(3D)运动学数据(自行和视向速度)测试了DBSCAN(Density-Based Spatial Clustering of Applications with Noise)聚类算法的成员判定效果.为了避免自行和视向速度的单位不一致带来的影响,在数据预处理阶段将3个分量的数据统一标准化至[0,1]区间.利用第k个最近邻点距离方法分析了1046颗恒星样本在标准化无量纲3D速度空间的分布特征,再根据第k个最近邻点距离随k值的变化趋势确定了DBSCAN聚类算法的输入参数(Eps,MinPts),最后利用DBSCAN聚类算法分离出497颗3D运动学成员星.分析结果表明得到的3D运动学成员星是可靠的.
基金supported by the Sichuan Science and Technology Program(Grant No.2020YFSY0034)Fundamental Research Funds of China West Normal University(Grant Nos.17C051,16E016)support from the National Natural Science Foundation of China(No.12073090)。
文摘This work presents a time-series photometric variability survey of the young open cluster NGC 869.More than 13000 CCD frames in the BV filters were collected on 19 nights between 2014 November 6 and 2014 December 24.In a 20’×20’field centered on the cluster,we detected a total of 28 stars showing photometric variability,12 of which are new discoveries.The classifications and memberships of the variable stars are discussed according to the behaviors and periods of the light curves as well as their positions on the H-R diagram.These results conclude that 22 variable stars are probable members of the cluster while six other stars belong to the field star population.They are categorized as 18 pulsating variable stars(fourβCep,seven SPB,oneβCep/SPB,four Be stars,and twoδSct/γDor candidates),seven eclipsing binaries(five EA and two EB)and three unknown type stars.
基金supported by the Meritocracy Research Funds of China West Normal Universitythe Fundamental Research Funds of China West Normal University
文摘We present the first CCD photometric observations of open cluster NGC 744, as part of the 50 BiN Open Cluster Survey. The color-magnitude diagrams of this cluster were derived from absolute BV RI photometry on a good photometric night. A brief isochrone fitting gives a distance modulus of(m-M)V= 11.58±0.2 and a reddening of E(B-V) = 0.35±0.05 with an age of log t = 8.30±0.05.By carefully examining the BV time-series data, we discovered four new variable stars in a 20′×20′field around the cluster. We classified them as three eclipsing binary stars and one δ Scuti pulsating star,mainly based on the light-curve shape, the detected periods and the positions on the color-magnitude diagrams.
基金supported by the National Natural Science Foundation of China under Grant No.11273051the program of Light in China Western Region(LCWR,Grant Nos.XBBS201221 and 2015-XBQN-A-02)
文摘This paper presents Charge-Coupled Device time-series photometric observations of the open cluster NGC 1582 and its surrounding field with Johnson B,V and R filters by using the Nanshan 1 m telescope administered by Xinjiang Astronomical Observatory.19 variable stars and three variable candidates were detected in a 45′×48.75′ field around the cluster.12 of the variable stars are newly-discovered variable objects.The physical properties,classifications and memberships of these 22 objects are studied through their light curves,their positions on the color-magnitude diagram and with archival data from the Naval Observatory Merged Astrometric Dataset.Among these objects,five are eclipsing binary systems,six are pulsating variable stars including one known S Scuti star and one newly-discovered RR Lyrae star.The distance to the RR Lyrae star is estimated to be 7.9 ± 0.3 kpc,indicating that the star is located far behind the cluster.Four variable stars are probable members of the cluster,and 13 of the 22 objects are confirmed to be field stars.
基金Supported by the National Natural Science Foundation of China.
文摘We present the results of a time-series CCD photometric survey ofvariable stars in the field of the open cluster NGC 7789. In a field of about onedegree centering on the cluster, a total of 28 new variable stars are discovered(14 W UMa systems, nine EA-type eclipsing binaries, one RR Lyr star, and fourunclassified). In addition, we recovered 11 old variables previously discovered byother authors. Preliminary parameters are given for some of these variables.
