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1911. Light curves of Algol-type binaries. VII. V404 And
ID:
ivo://CDS.VizieR/J/AJ/147/66
Title:
Light curves of Algol-type binaries. VII. V404 And
Short Name:
J/AJ/147/66
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present new CCD light curves of the short-period Algol-type eclipsing binary V404 And obtained in 2009-2011. The time-resolving multiple BVRI color light curves of the year 2011 with full phase coverage were analyzed simultaneously using the latest Wilson-Devinney program. We concluded that the configuration of two starspots on the primary is the most reliable explanation for the light curve distortions observed in 2011. Based on the new photometric solution, we further applied the spot model to explain the other light curves, including the previously published R-band light curves. We revealed that the starspots changed on a long timescale in terms of the spot parameters and the differences between Max.I and Max.II. Moreover, the O-C diagram spanning about 15yr shows an upward parabola, which indicates a secular increase in the orbital period of V404 And. The orbital period increases at a rate of dP/dt=5.3(0.3)x10^-7^days/yr, which might be interpreted by the angular momentum exchange via magnetic activity.
1912. Light curves of AV Hya and DZ Cas
ID:
ivo://CDS.VizieR/J/AJ/144/50
Title:
Light curves of AV Hya and DZ Cas
Short Name:
J/AJ/144/50
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present BVR photometric observations and several eclipsing times for AV Hya and DZ Cas from 2004 to 2011. Using the Wilson-Devinney method, the photometric solutions with hot spots were deduced from their asymmetric light curves. The results indicate that both stars are Algol-type binaries, whose mass ratio, q_ph_, and fill-out factor of the primary, f_1_, are q_ph_=0.255(+/-0.002) and f_1_=81.2(+/-0.2)% for AV Hya, and q_ph_=0.093(+/-0.003) and f_1_=98.7(+/-0.3)% for DZ Cas. Based on all available light minimum times, it is discovered that the O-C curve of each star could be described by a light-time orbit overlying on a downward parabola. Their periods and amplitudes are P_3_=37.2(+/-0.7)yr and A=0.0095'(+/-0.0006') for AV Hya, and P_3_=62.5(+/-1.0)yr and A=0.0183'(+/-0.0007') for DZ Cas. Cyclic variations may result from the light-time effect due to the third body. The secular period decrease rates are dP/dt=-1.47(+/-0.04)x10^-7^days/yr for AV Hya and dP/dt=-0.92(+/-0.04)x10^-7^days/yr for DZ Cas. This may be interpreted using mass and angular momentum loss from the system. With decreasing period, the fill-out factor of the primary increases and it may finally fill its inner Roche lobe. Therefore, AV Hya and DZ Cas with a secular period decrease will evolve from semi-detached configurations into contact ones.
1913. Light curves of four overcontact binaries
ID:
ivo://CDS.VizieR/J/AJ/148/126
Title:
Light curves of four overcontact binaries
Short Name:
J/AJ/148/126
Date:
21 Oct 2021
Publisher:
CDS
Description:
We analyze new, high quality multicolor light curves of four overcontact binaries: AK Her, HI Dra, V1128 Tau, and V2612 Oph, and determine their orbital and physical parameters using the modeling program of G. Djurasevic and recently published results of radial velocity studies. The achieved precision in absolute masses is between 10% and 20%, and the precision in absolute radii is between 5% and 10%. All four systems are W UMa-type binaries with bright or dark spots indicative of mass and energy transfer or surface activity. We estimate the distances and the ages of the systems using the luminosities computed through our analysis, and perform an O-C study for V1128 Tau, which reveals a complex period variation that can be interpreted in terms of mass loss/exchange and either the presence of the third body, or the magnetic activity on one of the components. We conclude that further observations of these systems are needed to deepen our understanding of their nature and variability.
1914. Light curves of four transients from PTF & SNLS
ID:
ivo://CDS.VizieR/J/ApJ/819/35
Title:
Light curves of four transients from PTF & SNLS
Short Name:
J/ApJ/819/35
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present observations of four rapidly rising (t_rise_~10days) transients with peak luminosities between those of supernovae (SNe) and superluminous SNe (M_peak_~-20) --one discovered and followed by the Palomar Transient Factory (PTF) and three by the Supernova Legacy Survey (SNLS). The light curves resemble those of SN 2011kl, recently shown to be associated with an ultra-long-duration gamma-ray burst (GRB), though no GRB was seen to accompany our SNe. The rapid rise to a luminous peak places these events in a unique part of SN phase space, challenging standard SN emission mechanisms. Spectra of the PTF event formally classify it as an SN II due to broad H{alpha} emission, but an unusual absorption feature, which can be interpreted as either high velocity H{alpha} (though deeper than in previously known cases) or SiII (as seen in SNe Ia), is also observed. We find that existing models of white dwarf detonations, CSM interaction, shock breakout in a wind (or steeper CSM), and magnetar spin down cannot readily explain the observations. We consider the possibility that a "Type 1.5 SN" scenario could be the origin of our events.
1915. Light curves of GN Boo, BL Leo, and V1918 Cyg
ID:
ivo://CDS.VizieR/J/AJ/145/60
Title:
Light curves of GN Boo, BL Leo, and V1918 Cyg
Short Name:
J/AJ/145/60
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present new photometry for three short-period contact binaries, GN Boo, BL Leo, and V1918 Cyg, observed from 2008 December to 2012 April using several small telescopes in China. Photometric models were deduced from new observations using the updated Wilson-Devinney Code. The results show that GN Boo and BL Leo are W-type contact binaries, while V1918 Cyg is an A-type one. The mass ratios and fill-out factors are q=0.320(+/-0.002) and f=5.8(+/-0.1)% for GN Boo, q=0.476(+/-0.005) and f=21.3(+/-1.1)% for BL Leo, q=0.264(+/-0.002), and f=49.7(+/-0.7)% for V1918 Cyg, respectively. From the (O-C) curves, it is discovered that the orbital periods of three binaries have varied in a complicated way, i.e., cyclic oscillation for GN Boo, long-term period decrease for BL Leo, and both for V1918 Cyg. The cyclic variations for GN Boo and V1918 Cyg may probably be attributed to the magnetic activity of the primary component or light-time effect due to the third body. Meanwhile, the secular period decreases for BL Leo and V1918 Cyg may result from mass transfer from the primary to the secondary, accompanying the mass and angular momentum loss from the central system. Finally, GN Boo, BL Leo, and V1918 Cyg will evolve into deep contact binaries. Additionally, a statistical study of 37 contact binaries with decreasing periods is given. We obtained the relations of q-f and q-dlnP/dt, and preliminarily determined the mass loss rate of dln M/dt from the binary system.
1916. Light curves of HS Aqr, EG Cep, VW LMi, DU Boo
ID:
ivo://CDS.VizieR/J/AJ/145/80
Title:
Light curves of HS Aqr, EG Cep, VW LMi, DU Boo
Short Name:
J/AJ/145/80
Date:
21 Oct 2021
Publisher:
CDS
Description:
We analyze new multicolor light curves for four close late-type binaries: HS Aqr, EG Cep, VW LMi, and DU Boo, in order to determine the orbital and physical parameters of the systems and estimate the distances. The analysis is done using the modeling code of G. Djurasevic, and is based on up-to-date measurements of spectroscopic elements. All four systems have complex, asymmetric light curves that we model by including bright or dark spots on one or both components. Our findings indicate that HS Aqr and EG Cep are in semi-detached, while VW LMi and DU Boo are in overcontact configurations.
1917. Light curves of Ibc supernovae
ID:
ivo://CDS.VizieR/J/ApJ/741/97
Title:
Light curves of Ibc supernovae
Short Name:
J/ApJ/741/97
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present detailed optical photometry for 25 Type Ibc supernovae (SNe Ibc) within d~150Mpc obtained with the robotic Palomar 60 inch telescope in 2004-2007. This study represents the first uniform, systematic, and statistical sample of multi-band SNe Ibc light curves available to date. We correct the light curves for host galaxy extinction using a new technique based on the photometric color evolution, namely, we show that the (V-R) color of extinction-corrected SNe Ibc at {Delta}t~10days after V-band maximum is tightly distributed, <(V-R)_V10_>=0.26+/-0.06mag. Using this technique, we find that SNe Ibc typically suffer from significant host galaxy extinction, <E(B-V)>~0.4mag. A comparison of the extinction-corrected light curves for helium-rich (Type Ib) and helium-poor (Type Ic) SNe reveals that they are statistically indistinguishable, both in luminosity and decline rate. We report peak absolute magnitudes of <M_R_>=-17.9+/-0.9 mag and <M_R_>=-18.3+/-0.6mag for SNe Ib and Ic, respectively.
1918. Lightcurves of minor planets
ID:
ivo://CDS.VizieR/J/A+AS/112/125
Title:
Lightcurves of minor planets
Short Name:
J/A+AS/112/125
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present 81 photometric lightcurve of 36 minor planets observed in the V and B bands at the ESO 50cm telescope at La Silla (Chile). These asteroids were selected preferentially in order to improve their ecliptic longitude coverage in view of pole determinations and lightcurve inversions. We also give some first photometric observations and/or rotational period for several asteroids.
1919. Light curves of M9 variables
ID:
ivo://CDS.VizieR/J/other/PDDO/1.511
Title:
Light curves of M9 variables
Short Name:
J/other/PDDO/1.5
Date:
21 Oct 2021
Publisher:
CDS
Description:
Time-series photographic photometry for the variable stars in M9.
1920. Light curves of NGC 6910 pulsating stars
ID:
ivo://CDS.VizieR/J/A+A/632/A95
Title:
Light curves of NGC 6910 pulsating stars
Short Name:
J/A+A/632/A95
Date:
21 Oct 2021
Publisher:
CDS
Description:
The aim of this study is to obtain the age of the open cluster NGC 6910 by means of ensemble asteroseismology of the early-type pulsating members, to derive their stellar parameters, and to classify the excited modes. We used time-series analysis, performed photometric and spectroscopic mode identification, and calculated grids of evolutionary and seismic models to apply the procedure of ensemble asteroseismology for nine pulsating members of NGC 6910. With two iterations of the procedure of ensemble asteroseismology we derived an age of 10.6^+0.9^_-0.8_Myr for NGC 6910. We also identified the degree l for 8 of 37 modes detected in these stars and classified all modes in terms of p, g, and mixed-mode pulsations. Of the nine pulsating stars examined in the paper, eight are {beta} Cep stars, including three that are hybrid {beta} Cep and slowly pulsating B-type (SPB) pulsators, and one is an SPB star. Interestingly, the least massive {beta} Cep star, NGC 6910-38, has a mass of about 5.6 solar masses. The present theory does not predict unstable p modes in B-type stars with such a low mass. The g modes with relatively high frequencies (>3.5d^-1^), observed in three members of the cluster, are also stable according to seismic modelling. Both findings pose a challenge for theoretical calculations and prompt a revision of the opacities. The procedure of ensemble asteroseismology was found to be successful for NGC 6910 and {chi} Per on the basis of pulsating B-type stars and can therefore be applied to other young open clusters that are rich in such stars.