PoS(APCS2018)028 https://pos.sissa.it/ , Shengbang Qian, Xiangdong Shi ∗ [email protected] Speaker. LAMOST has a wide fieldlions of spectra view were and obtained by a LAMOST veryspectra. till high now. spectrum Such Among them, acquiring huge more rate. stellar thancorresponding spectra 8 More fields. database millions than are will Eclipsing 9 stellar binaries stimulate mil- are theprovide very deep important precise study sources information of in about astrophysics stellar absolute because physics12923 parameters they and eclipsing of binary the stars, components. which greatlybinaries. LAMOST expanded observed the We spectroscopic provided information the ofspectral eclipsing eclipsing types binary obtained by catalogue LAMOST. with Inbinaries this stellar paper, observed atmospheric we by parameters introduce LAMOST. the and differentstudy kinds As of of the an eclipsing EW-type example eclipsing of binarythe NSVS4692753. the parameters follow-up Combined obtained the observation, by complete LAMOST, we we lightthat present curves analyzed NSVS4692753 the and its is muli-color a light low curves.OurW-type results mass contact show ratio binary (mass system. ratioasymmetric 5.0) The light and third variation deep light detected contact in contributionondary. (fill-out the was NSVS4692753 factor is light detected the 64%) curve special in system was all at explainedmaybe the bands the late by progenitor evolutionary and a stage of the of dark the contact luminous spot binaries, red and in nova, which the is sec- a rare class of optical transients. ∗ Copyright owned by the author(s) under the terms of the Creative Commons c ⃝ Attribution-NonCommercial-NoDerivatives 4.0 International License (CC BY-NC-ND 4.0). Accretion Processes in Cosmic Sources —3–8 II September - 2018 APCS2018 Saint Petersburg, Russian Federation Liying Zhu Observatories, Chinese Academy of Sciences,, 396 650216, Yangfangwang, P. Guandu R. , Center for Astronomical Mega-Science, Chinese AcademyChaoyang of District, Sciences, Beijing, 20A 100012, Datun P. Road, R.Key China Laboratory for the Structure andSciences, Evolution 396 of Yangfangwang, Celestial Guandu Objects, District, Chinese Kunming, AcademyUniversity 650216, of of P. R. the China Chinese Academy ofBeijing, Sciences, P. R. Yuquan Road China 19#, SijingshangE-mail: Block, 100049 Eclipsing Binaries Observed by LAMOST PoS(APCS2018)028 ]). 15 , ]), the ]) (e.g. 4 14 , 20 , Liying Zhu 3 , 13 19 ]) and Super- ([ r 11 V ]), the Northern Sky 7 , 6 ]), the HATNet Survey ([ 10 , 9 , the standard deviations are 4.91 km/s when r V 1 , the standard deviations are 110 K, 0.19 dex and 0.11 dex for K ]), Kepler mission ([ ]), the All Sky Automated Survey (ASAS, [ 8 5 8000 ]). These parameters are tabulated and available online([ < 18 e f f T ]), a large number of light curves of eclipsing binaries were obtained. However, ]. That means it can collect several ten-thousands of spectra per night. The wave- 2 (e.g., [ 12 , 1 K ]). When 10000 17 < Till now, there are 12923 eclipsing binary stars were observed by LAMOST. Among them, According to big photometric surveys, such as the Catalina Sky Survey (CSS; [ Eclipsing binaries are very important sources in astrophysics because they can provide precise LAMOST (Large Sky Area Multi-Object Fiber Spectroscopic Telescope, also called as Gu- , gravitational acceleration log(g), metallicity [Fe/H] and radial velocity (RV) , log(g) and [Fe/H] respectively. For RV , 16 e f f e f f e f f http://search.vbscn.com/CEW.table1.txt, http://search.vbscn.com/CEA.table2.txt), so that one can WASP survey ([ T T the spectral information of them arespectra insufficient. from The the enormous LAMOST amount of survey data provide representing important stellar information for studying eclipsing binaries. the spectra of 8729 eclipsingatmospheric binaries had parameters. sufficiently high These signal stellarT to atmospheric noise parameters to determine include the the stellar effective temperature 2. Eclipsing binaries observed by LAMOST Variability Survey (NSVS; [ They were determined based on([ the Universite de Lyon spectroscopic analysis software (ULySS) absolute parameters (e.g. mass, radius etc.)scopic observations. of According the to components, the based shapes onthree of photometric groups, light and curves, i.e., spectro- eclipsing binaries EA-, canwith EB- be spherical and divided or into EW-types. slightly ellipsoidal EA-typethe stellar eclipsing beginning components. and systems the (EAs) It end of are isalmost the possible close constant eclipse to or binaries on varies specify their insignificantly light the that curves.binary moments is Out components, caused of of or by the physical reflection eclipses, variations. effects the The andeach light properties slight other. remains indicate ellipsoidal EAs that of could they are be not semi-detached(EWs) in system eclipsing contact or systems with detached are system. closeare EB-type binaries continuous (EAs) and having and cannot ellipsoidal EW-type be components. specifiedof the Their exact the times light primary of variations and onset and secondaryindicates the minima that end of of the eclipses. EWs two The are componentsmasses depths almost of of equal, the EWs while two are components that insemidetached are of thermal or different. EBs marginal contact Generally, contact are EWs while binaries. not. are EBs the are This contact not, binaries though and EBs the are oshoujing Telescope) is a nationalences. major It scientific has a project wide built fieldone by of exposure the view [ of Chinese 5 Academy degrees and of can Sci- simultaneously obtain about 4000 spectra in EBs Observed by LAMOST 1. Introduction length range of LAMOST is fromand 370nm-900nm, red which is arm divided (570nm-900nm). intoAmong blue them, Now, arm (370nm-590nm) more more than thanstimulate 9 8 the millions corresponding millions researches spectra are in were astrophysics. stellar obtained spectra. by LAMOST. Such huge stellar spectra database will asteroid survey LINEAR ([ PoS(APCS2018)028 Liying Zhu , gravitational ac- ]. It was observed e f f 25 T . We will update the table by adding r V ]) and will merge into rapidly rotating 23 ] studied the distribution and correlations , 19 22 filters were used. Employing the WD code c I c 2 BVR Bessel − Cousin of 5800K were determined by LAMOST data. Using 70 cm telescope − e f f T ]). 8521 EWs were observed by LAMOST. Among them, 5872 have their 24 , 21 ]), we analyzed the light curves by fixing the effective temperature of the primary 28 , ] 27 Our results show that NSVS4692753 is a low mass ratio (mass ratio 5.0) and deep contact The light variation of NSVS4692753 was discovered by Hoffman et al.[ According to the LAMOST data, not only some new binaries were detected, but also some EWs have the lowest angular momentum and shortest orbital periods among main-sequence , 20 26 (fill-out factor 64%) W-type contactall binary bands. system. NSVS4692753 The is third the light special system contribution at was the detected late in evolutionary stage of contact binaries. component as 5800 K obtainedvalue achieved by at LAMOST. 5.0. The The q-search corresponding(dots) theoretical (see are light Fig curves plotted 2)result (solid in lines) shows and Fig0.25, the the 0.5 3. minimal observations and 0.75. Fig The 4 asymmetricin light shows the variation the in secondary its geometric component light structure of curveclearly was of NSVS4692753. in explained Fig NSVS4692753 by 4. The at the detail dark phase spot location 0.0, of the dark spot can be seen 3. Follow-up Observations special eclipsing binaries were found, suchbe as caused some by unusually contamination high of metallicities material targets fromthe which the systems may evolution etc. of unseen The neutron follow-up starsparameters observations or of based black LAMOST holes on in binaries the are photometric usefulevolution and to of spectroscopic derive data the the reliable together, close andeclipsing binaries. study binary the NSVS4692753 We structure for present and example. here the follow-up observation and investigation of binaries. One of the formation scenarioangular of momentum EWs is loss that via from magnetic short-period braking detached binaries (e.g., through [ LAMOST stellar atmospheric parameters. Qian et al.[ EBs Observed by LAMOST search these LAMOST parameters for specificthe eclipsing binary binaries, easier. their The coordinates, table types includes ofand names light of the variation, orbital input periods, object, distance observed betweenceleration date, LAMOST log(g), spectral metallicity type, [Fe/H] and the radial effective velocitynew temperature (RV) data obtained by LAMOST in the future. single stars ([ of these parameters in detail and80.6% of got sample some stars physical have properties metallicity ofEBs below zero, EWs. are indicating usually Such that the as, EWs connections they aremake found old of them stellar about EWs populations. a and EAs. good astrophysicalatmospheric Their laboratory parameters semidetached to or of marginal study 424 characteristic EAs, mass EBs the transfer were number in obtained is close among 2020al.[ binaries. 605 among EBs 3196 The systems. observed stellar by The LAMOST. detailed For statistics work was done by Qian et by LAMOST twice on Decembereffective temperature 27, 2015 and Mayin 15, 2016. station of The Yunnanthis spectral Observatories, system, type We obtained of which the G2 are complete andand displayed muti-color the the in light standard Fig curves Johnson of 1. During the observation, an Andor 2K CCD camera ([ PoS(APCS2018)028

Liying Zhu

1.0 q=5.0 0.8 ]. The luminous red nova is a new type achieved at achieved 0.6 24 q

3 Phase curve for NSVS4692753. 0.4 q T he minimum − Σ 0.2 The 0.0 Ic V B Rc Figure 2: 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0 6.5 C-CH-0.4 C-CH-0.4 C-CH-0.4 C-CH-0.4 0.0017 0.0016 0.0015 0.0014 0.0013 0.0012 0.0011 0.0010 0.0009 0.0008

0.4 0.6 0.8 1.0 1.2 1.4 1.6 m The muti-color light curves of NSVS4692753 observed by 70 cm telescope. Figure 1: A huge amount of stellar spectra obtained by LAMOST is very useful for the field of eclipsing binary. We provided the eclipsing binary catalogue withtypes stellar obtained atmospheric parameters by and LAMOST, spectral whichinteresting is studies a are great aroused information and expansion need of for follow-up eclipsing in binaries. the future. Many 4. Conclusion EBs Observed by LAMOST It may evolve from the presentstar low-mass and ratio produce and a deep-contact luminous binaryof into red stellar a nova explosion. single like rapid-rotation V1309 It Sco isbrightest [ a classical rare novae, but class lower of than opticalstellar supernovae. explosion. transients. NSVS4692753 maybe The the peak progenitor luminosity of is such higher than the PoS(APCS2018)028

Liying Zhu

1.0

0.8 0.4 0.0 -0.4 -0.8 0.8 0.4 0.0 -0.4 -0.8 0.8 0.8 0.8 , V, B band light curves light V,B , band c 0.4 0.4 , R , c

0.0 0.0 -0.4 -0.4 0.6 -0.8 -0.8 Observations curves light Theoretical Phase=0.25 Phase=0.75 From top to the bottom show I show bottom the to top From Phase

4

0.4 0.8 0.8 0.4 0.4 Phase=0.00 Phase=0.50

0.0 0.0 0.2 -0.4 -0.4 -0.8 -0.8 Observed and theoretical light curves of NSVS4692753. 0.0 0.8 0.4 0.0 0.8 0.4 0.0

-0.4 -0.8 -0.4 -0.8

0.4 0.5 0.6 0.7 0.8 0.9 1.0 1.1 m Geometrical structure of NSVS4692753 at phase 0.0, 0.25, 0.5 and 0.75. Figure 3: Figure 4: Cui, X. Q., Zhao, Y. H., Chu, Y. Q., et al. 2012, RAA, 12, 1197 This work is partly supported by the National Natural Science Foundation of China (Nos. [1] 11573063), the Key Science FoundationWest China" of Program Yunnan Province and (No. CASLarge Sky Interdisciplinary 2017FA001), Area Innovation Multi-Object CAS Fiber Team. "Light Spectroscopic Telescope of tific Guoshoujing LAMOST) is Project Telescope a built (the National by Major the Scien- Chineseby Academy the of National Sciences. Development Funding and forthe the Reform National project Astronomical Commission. has Observatories, been Chinese LAMOST provided observations Academy is were of obtained operated with Sciences. and the 70cm New managed telescope CCD by at photometric Lijiang station of the Yunnan Observatories. References Acknowledgments EBs Observed by LAMOST PoS(APCS2018)028 Liying Zhu 5 ´ ccs, G., et al. 2004, PASP, 116, 266 l ´ Wilson, R. E., 1990, ApJ 356, 613 Wilson, R. E., 1994, PASP 106, 921 Bradstreet, D. H., & Guinan, E.Interacting F. Binary 1994, Stars, in ed. Astronomical A. Society W. of Shafter, the 228 PacificZhu, Conference L.-Y., Series, Zhao, 56, E.-G., Zhou, X., 2016, RAA (ResearchHoffman, in D. Astronomy I.; and Harrison, Astrophysics), T. E.; 16, McNamara, 68 B. J.,Wilson, R. 2009, E. AJ, & 138, Devinney, 466 E. J., 1971, ApJ 166, 605 Qian, S.-B., Zhu, L.-Y., Soonthornthum, B., Yuan, J.-Z., Yang, Y.-G.,Guinan, He, E. J.-J., F., 2005, & AJ, Bradstreet, 130,1206 D.eds. H. A. 1988, K. in Dupree NATO Advanced & Science M. Institutes T. (ASI) V. T. Series Lago, C, 345 241, Wu, Y., Singh, H. P., Prugniel, P., Gupta, R., &Gao, Koleva, H., M.2011a, Zhang, A&A, H.-W., 525, Xiang, A71 M.-S.,15, et 2204 al. 2015, RAA (Research in Astronomy andQian, Astrophysics), S.-B., He, J.-J., Zhang, J.,in Zhu, Astronomy L.-Y., and Shi, Astrophysics), X.-D., 17, Zhao, 87 E.-G., Zhou, X.,Qian, 2017, S.-B., RAA Zhang, (Research J., He, J.-J.,ApJS, Zhu, 235, L.-Y., 5 Zhao, E.-G., Shi, X.-D., Zhou, X., Han, Z.-T., 2018, Luo, A.-L., Zhao, Y.-H., Zhao, G.,1095 et al. 2015, RAA (Research in Astronomy andKoleva, Astrophysics), M., 15, Prugniel, P., Bouchard, A., & Wu, Y. 2009, A&A, 501, 1269 Howell, S. B., Sobeck, C., Haas, M., etBakos, al. G., 2014, Noyes, PASP, 126, R. 398 W., Kov Pollacco, D. L., Skillen, I., Collier Cameron, A.,Wu, et Y., Luo, al. A.-L., 2006, Li, PASP, 118, H.-N., 1407 et al. 2011b,Wu, RAA Y., Du, (Research B., in Luo, Astronomy A., andin Zhao, Astrophysics), 21st Y., 11, & Century 924 Yuan, Cosmology, H. eds. 2014, A. in Heavens, IAU J.-L. Symposium, Starck, 306, & Statistical A. Challenges KroneMartins, 340 Wozniak, P. R., Vestrand, W. T., Akerlof, C. W., etBorucki, al. W. 2004, J., AJ, Koch, 127, D., 2436 Basri, G., et al. 2010, Sci, 327, 977 Wang, S. G., Su, D. Q., Chu, Y. Q.,Drake, et A. al. J., 1996, Djorgovski, ApOpt, S. 35, G., 5155 Mahabal, A.,Drake, et A. al. J., 2009, Graham, ApJ, M. 696, J., 870 Djorgovski, S.Palaversa, G., L., et Ivezic, al. Z., 2014, Eyer, ApJS, L., 213, et 9 al. 2013,Pojmanski, AJ, G. 146, 1997, 101 AcA, 47, 467 Pojmanski, G., Pilecki, B., & Szczygiel, D. 2005, AcA, 55, 275 [9] [4] [5] [6] [7] [8] [2] [3] [27] [28] [24] [25] [26] [21] [22] [23] [19] [20] [15] [16] [17] [18] [12] [13] [14] [10] [11] EBs Observed by LAMOST