The First Photometric Analyses Of Four New Discovered Ew-Type Eclipsing Binaries: GSC 1848-1264, GSC 0804-0118, GSC 0619-0232 And GSC 2936-0478

Photometric solutions of four new discovered W UMa-type binaries were carried out for the first time by using the 2003 version of the W-D program. It is discovered that all of the four systems are over-contact binaries. Two binaries, GSC 0804-0118 and GSC 2936-0478, are of A-subtype, while two other binaries, GSC 1848-1264 and GSC 0619-0232, are of W-subtype. From our solutions, the fundamental orbital and physical parameters were determined. For GSC 0619-0232 and GSC 2936-0478, the asymmetries of the light curves (i.e., the O'Connell effect) were explained by the presence of dark spots on the more massive components. Our photometric results reveal that GSC 0619-0232 is an important and interesting system. It is a W-type over-contact binary with a low mass ratio of q = 0.100 and a high over-contact degree of f = 93.4%, which suggests that GSC 0619-0232 may be evolved into a single rapid-rotating star.     

Discovery of Four Peculiar Variable Stars

Four stars, GSC 1258-0143, GSC 1986-1665, GSC 3045-0892 and GSC 2983-1597 were found to be new variables during a campaign of CCD photometric monitoring of short-period eclipsing binary stars. The variabilities of these new variables are reported. The main characteristics and probable classifications of the variables are discussed through a preliminary analysis on their light curves. Among these stars, GSC 1258-0143 is classified as a RR Lyr star of sub-type a. Its pulsation period is determined to be about 0.5206 days. The other three stars, are definite variables, but their periods and types of light variations remain unknown.     

A NanoSIMS and Raman spectroscopic comparison of interplanetary dust particles from comet Grigg‐Skjellerup and non‐Grigg Skjellerup collections

Abstract– Interplanetary dust particles (IDPs) are the most primitive extraterrestrial material available for laboratory studies and may, being likely of cometary origin, sample or represent the unaltered starting material of the solar system. Here we compare IDPs from a “targeted” collection, acquired when the Earth passed through the dust stream of comet 26P/Grigg‐Skjellerup (GSC), with IDPs from nontargeted collections (i.e., of nonspecific origin). We examine both sets to further our understanding of abundances and character of their isotopically anomalous phases to constrain the nature of their parent bodies. We identified ten presolar silicates, two oxides, one SiC, and three isotopically anomalous C‐rich grains. One of seven non‐GSC IDPs contains a wealth of unaltered nebula material, including two presolar silicates, one oxide, and one SiC, as well as numerous δD and δ¹⁵N hotspots, demonstrating its very pristine character and suggesting a cometary origin. One of these presolar silicates is the most ¹⁷O‐rich discovered in an IDP and has been identified as a possible GEMS (glass with embedded metal and sulfides). Organic matter in an anhydrous GSC IDP is extremely disordered and, based on Raman spectral analyses, appears to be the most primitive IDP analyzed in this study, albeit only one presolar silicate was identified. No defining difference was seen between the GSC and non‐GSC IDPs studied here. However, the GSC collectors are expected to contain IDPs of nonspecific origin. One measure alone, such as presolar grain abundances, isotopic anomalies, or Raman spectroscopy cannot distinguish targeted cometary from unspecified IDPs, and therefore combined studies are required. Whilst targeted IDP populations as a whole may not show distinguishable parameters from unspecified populations (due to statistics, heterogeneity, sampling bias, mixing from other cometary sources), particular IDPs in a targeted collection may well indicate special properties and a fresh origin from a known source.     

New multiple systems of the Trapezium type

In the Guide Star Catalog (GSC) 223 new trapezia have been found. A new, more complete list of trapezia, including 637 objects, has been compiled on the basis of the GSC and the Washington Double Star Catalog. Translated from Astrofizika, Vol. 42, No. 4, pp. 571–578, October–December, 1999.     

变星及发射线星系的计算机自动搜索

本文发展了一套计算机自动证认、交叉比对的技术,应用于1989年9月至12月间北京天文台60/90cm施密特望远镜的CCD测光资料及GSC星表,由二个系统的V星等资料,在6个平方度内找到5颗变星;利用二个系统B颜色带宽的不同,进行发射线星系巡天,在3个平方度内找到15个致密核发射线星系.并讨论了本方法用于光变天体、包指数反常天体、位置移动天体、发射线天体巡天的可能性.     

Photometric Studies of Twelve Deep, Low-mass Ratio Overcontact Binary Systems

The formations of the blue straggler stars and the FK Com-type stars are unsolved problems in stellar astrophysics. One of the possibilities for their formations is from the coalescence of W UMa-type overcontact binary systems. Therefore, deep (f > 50%), low-mass ratio (q < 0.25) overcontact binary stars are a very important source to understand the phenomena of Blue Straggler/FK Com-type stars. Recently, 12 W UMa-type binary stars, FG Hya, GR Vir, IK Per, TV Mus, CU Tau, V857 Her, V410 Aur, XY Boo, SX CrV, QX And, GSC 619-232, and AH Cnc, were investigated photometrically. Apart from TV Mus, XY boo, and GSC 619-232, new observations of the other 9 binaries were obtained. Complete light curves of the 10 systems, FG Hya, GR Vir, IK Per, TV Mus, CU Tau, V857 Her, GSC 619-232, V410 Aur, XY Boo, and AH Cnc, were analyzed with the 2003 version of the W-D code. It is shown that all of those systems are deep (f > 50%), low-mass ratio (q < 0.25) overcontact binary stars. We found that the system GSC 619-232 has the highest degree of overcontact (f = 93.4%). The derived photometric mass ratio of V857 Her, q = 0.0653, indicates that it is the lowest-mass ratio system among W UMa-type binaries.Of the 12 sample stars, long-term period changes of 11 systems were found. About 58% (seven) of the sample binaries show cyclic period oscillation. No cyclic period changes were discovered for the other 5 systems, which may be caused by the short observational time interval or by insufficient observations. Therefore, we think that all W UMa-type binary stars may contain cyclic period variations. By considering the long-term period changes (both increase and decrease) of those binary stars, we proposed two evolutionary scenarios evolving from deep, low-mass ratio overcontact binaries into Blue Straggler/FK Com-type stars.     

GSC3658-0076: A Binary System at the Beginning of Mass Transfer

Photometric data of the new discovered binary GSC3658-0076 observed by [González-Rojas et al.: 2003, IBVS, No. 5437.] were analyzed using the latest Wilson-Devinney code. The system turns out to be a detached binary system with the primary component almost filling its Roche lobe, while the secondary one is detached from the critical Roche lobe. According to the mass-radius relation of unevolved (ZAMS) detached binaries given by [Demircan and Kahraman: 1991, Ap&SS 181, 313.], the primary component is more evolved. These properties reveal that GSC3658-0076 may be at the beginning of the mass transfer phase and may evolve from the present detached system into a contact binary or be in the broken-contact phase predicted by TRO theory.     

Analysis of observations of the dwarf nova pegasi 2010

Analysis of photometric and spectroscopic observations of GSC 02197-00886 at the outburst maximum (on May 8, 2010) and at the stage of relaxation towards the quiescent (on August 4, 2010) was performed. Radiation of an optically thick accretion disc with a hot boundary layer dominates the spectra, which are consistent with the spectra of a WZ Sge-type dwarf novae. In the relaxation phase, an optically thin accretion disc with radiation in the HI and HeI emission lines is observed against the background of the absorption spectrum of a white dwarf. The parameters of GSC 02197-00886, which were determined by combining the radial velocities of the components with the assumption that the secondary component is close to mainsequence stars, differ significantly from the parameters that characterize other WZ Sge-type systems. We hypothesize that the secondary component was excited in the course of the outburst and experienced long-lasting relaxation towards the main-sequence state.     

Photometric study of neglected eclipsing binary GSC 3576-0170

The new multi-color BVRI photometric light curves of the short-period eclipsing binary GSC 3576-0170 were obtained on two consecutive nights (October 5 and 6, 2009). With the 2003 version of Wilson–Devinney program, the precise photometric solutions are derived for the first time. The result shows that GSC 3576-0170 is a semi-detached binary system with a large temperature difference of approximately 1490 K. The light-curve distortions are further explained by a hot spot on the secondary component through mass transfer via a stream hitting the facing surface of the secondary component. By analyzing all available light minimum times, we also derived an update ephemeris and found for the first time a possible periodic oscillation with an amplitude of 0.0038 days and a period of 4.3 years. The periodic oscillation could be explained either by the light-time effect due to a presumed third component or by magnetic activity cycle of the system.     

新S星的IRAS证认

本文利用红外天文卫星点源表及哈勃望远镜导星星表对１９９０年新发表的７５个Ｓ星进行了ＩＲＡＳ红外源及ＧＳＣ光学对应体的证认，给出４１个Ｓ星有ＩＲＡＳ对应体，１２个Ｓ星有ＧＳＣ光学对应体。     

硅酸盐碳星的进一步证认

利用碳星星表（ＧＣＧＣＳ）、红外天文卫星（ＩＲＡＳ）点源表（ＰＳＣ）、哈勃望远镜（ＨＳＴ）导星星表（ＧＳＣ）及美国海军天文台星表（ＵＳＮＯ）对现今已知的２２个硅酸盐碳星重新进行了交叉证认,给出它们的确切位置,以利于今后进一步的观测研究,同时也指出其中存在值得怀疑的对象     

Proper motion and X‐ray selected search for new members of the young TW Hya association

We have searched for new members of the TWHya association (TWA) among unidentified ROSAT X‐ray sources by identifying them in proper motion catalogues and selecting those that would be consistent with kinematical membership to the TWA. Spectroscopic follow‐up observations of 19 member candidates revealed the detection of moderate lithium absorption lines for the following three stars: GSC 7206 845, TYC 7216‐55, and TYC 7247‐12. The isochronal ages of the latter TYC stars are estimated to be ∼20 Myr while the other one has ∼100 Myr age based on a kinematic distance estimate that assumes TWA membership. However, the moderately Li‐rich stars are not likely to be new pre‐main sequence members of TWA partly because of the discrepant radial velocities. Infrared follow‐up imaging in the H‐band for the 3 stars shows companion candidates near two of them.While one system (TYC 7216‐55) is probably a near‐equal‐magnitude stellar binary, our follow‐up H‐band spectrum of the faint companion candidate near GSC 7206 845 shows that it is instead a background K‐type star rather than a companion. (© 2003 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

GSC 45401533: Observations and Analysis of a NewlyDiscovered Binary Star

R observations of a newly discovered binary GSC 4540_1533 are presented. Analysis of the light curve with the Wilson-Devinney program indicates that the system is detached and consist of 2 main sequence stars. This revised version was published online in July 2006 with corrections to the Cover Date.     

Determination of proper motions for AC stars: First results

Proper motions of the stars of the Astrographic Catalogue are being derived, using the Hubble Space Telecope Guide Star Catalogue as second epoch. Results on the San Fernando and Cordoba AC zones are presented. Identification with GSC stars (i.e. determination of proper motion) was successful for 97 percent of all AC stars. Comparison of the proper motions thus derived with those of Preliminary PPM South shows that the accuracy is about 0.8 to 0.9 arcsec per century. Thus we can derive proper motions for about 4 million stars, with an accuracy higher than that of the SAO Catalogue.     

First light curve analysis of the high-amplitude Delta Scuti star GSC 4552–1498

We carried out observation of the HADS (High-Amplitude Delta Scuti) variable GSC 4552–1498 through three filters. Our goal was to consider its periodic behavior using our photometry data in addition to previous observations. A new ephemeris and determination of oscillation modes of the star based on Fourier analysis are presented. The Two color diagram of the star as a function of its phase is shown. Finally, some of the star's physical parameters including mass, radius and luminosity are calculated.     

An interesting nebular object in LDN 288

In this paper the results of multiwavelength investigation of an unusual nebular object SNO 85 are presented. In 2MASS images this object looks like a star with a jet. In DSS2 R image the end of the jet is connected with an interesting symmetric structure, consisting of arcs and loops. Such a structure is seen also in the opposite direction from the central star; it favors the existence of two opposite jets, which repeat the rotation and precession movements of the central star. The results of ¹²CO observations of the dark nebula LDN 288, connected with SNO 85, are also given. From these observations the following results were obtained: SNO 85 is situated in a dense condensation and the neighbor B type star GSC 0625400181 is surrounded by a hollow cavity. The velocity of the dark cloud is ∼2.5 km/s and its distance is estimated as (380–990) pc. The object SNO 85 itself is associated with an IRAS point source IRAS 17547-1832, the infrared colors of this source are typical for a non-evolved source embedded in the dense dark cloud. This region is perhaps a star formation one because there is also another star with a straight jet in the vicinity of B type star GSC 0625400181. Published in Astrofizika, Vol. 49, No. 4, pp. 621–629 (August 2006).     

Eclipsing binaries in the MOST satellite fields

Sixteen new eclipsing binaries have been discovered by the MOST satellite among guide stars used to point its telescope in various fields. Several previously known eclipsing binaries were also observed by MOST with unprecedented quality. Among the objects we discuss in more detail are short‐period eclipsing binaries with eccentric orbits in young open clusters: V578 Mon in NGC 2244 and HD 47934 in NGC 2264. Long nearly‐continuous photometric runs made it possible to discover three long‐period eclipsing binaries with orbits seen almost edge‐on: HD 45972 with P = 28.1 days and two systems (GSC 154 1247 and GSC 2141 526) with P > 25 days. The high precision of the satellite data led to discoveries of binaries with very shallow eclipses (e.g., HD 46180 with A = 0.016 mag, and HD 47934 with A = 0.025 mag). Ground‐based spectroscopy to support the space‐based photometry was used to refine the models of several of the systems (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

WASP-1b and WASP-2b: two new transiting exoplanets detected with SuperWASP and SOPHIE

We have detected low-amplitude radial-velocity variations in two stars, USNO-B1.0 1219–0005465 (GSC  02265–00107 = WASP–1  ) and USNO-B1.0 0964–0543604 (GSC  00522–01199 = WASP–2  ). Both stars were identified as being likely host stars of transiting exoplanets in the 2004 SuperWASP wide-field transit survey. Using the newly commissioned radial-velocity spectrograph SOPHIE at the Observatoire de Haute-Provence, we found that both objects exhibit reflex orbital radial-velocity variations with amplitudes characteristic of planetary-mass companions and in-phase with the photometric orbits. Line-bisector studies rule out faint blended binaries as the cause of either the radial-velocity variations or the transits. We perform preliminary spectral analyses of the host stars, which together with their radial-velocity variations and fits to the transit light curves yield estimates of the planetary masses and radii. WASP-1b and WASP-2b have orbital periods of 2.52 and 2.15 d, respectively. Given mass estimates for their F7V and K1V primaries, we derive planet masses 0.80–0.98 and 0.81–0.95 times that of Jupiter, respectively. WASP-1b appears to have an inflated radius of at least 1.33 R _Jup, whereas WASP-2b has a radius in the range 0.65–1.26 R _Jup.     

施密特巡天星表的现状和展望

扼要介绍了施密特巡天底片及基于此编制而成的施密特巡天星表的发展历程,并详细介绍了GSC2.3和USNO-B1.0的情况.分析研究了这类星表存在的问题和原因所在,并提出了一个新的计划:利用现有施密特底片资料并增加新的第3期观测,编制一个具有绝对自行、多色测光、系统均匀的高密度全天星表以满足各方面的需要.     

Photometric and spectroscopic observations of three rapidly rotating late‐type stars: EY Dra,V374 Peg,and GSC 02038‐00293

Here, BV (RI)_C broad band photometry and intermediate resolution spectroscopy in H_α region are presented for two rapidly rotating late‐type stars: EY Dra and V374 Peg. For a third rapid rotator, GSC 02038‐00293, intermediate resolution H_α spectroscopy and low resolution spectroscopy are used for spectral classification and stellar parameter investigation of this poorly known object. The low resolution spectrum of GSC 02038‐00293 clearly indicates that it is a K‐type star. Its intermediate resolution spectrum can be best fitted with a model with T_eff = 4750 K and v sin i = 90 km s^–1, indicating a very rapidly rotating mid‐K star. The H_α line strength is variable, indicating changing chromospheric emission on GSC 02038‐00293. In the case of EY Dra and V374 Peg, the stellar activity in the photosphere is investigated from the photometric observations, and in the chromosphere from the H_α line. The enhanced chromospheric emission in EY Dra correlates well with the location of the photospheric active regions, indicating that these features are spatially collocated. Hints of this behaviour are also seen in V374 Peg, but it cannot be confirmed from the current data. The photospheric activity patterns in EY Dra are stable during one observing run lasting several nights, whereas in V374 Peg large night‐tonight variations are seen. Two large flares, one in the H_α observations and one from the broadband photometry, and twelve smaller ones were detected in V374 Peg during the observations spanning nine nights. The energy of the photometrically detected largest flare is estimated to be 4.25 × 10³¹– 4.3 × 10³² erg, depending on the waveband. Comparing the activity patterns in these two stars, which are just below and above the mass limit of full convection, is crucial for understanding dynamo operation in stars with different internal structures (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)