- ID:
- ivo://CDS.VizieR/J/AJ/160/155
- Title:
- Light curve segments of 22 host stars with TESS
- Short Name:
- J/AJ/160/155
- Date:
- 10 Dec 2021
- Publisher:
- CDS
- Description:
- We present a systematic phase curve analysis of known transiting systems observed by the Transiting Exoplanet Survey Satellite (TESS) during year one of the primary mission. Using theoretical predictions for the amplitude of the planetary longitudinal atmospheric brightness modulation, stellar ellipsoidal distortion and Doppler boosting, as well as brightness considerations to select targets with likely detectable signals, we applied a uniform data processing and light-curve modeling framework to fit the full-orbit phase curves of 22 transiting systems with planet-mass or brown dwarf companions, including previously published systems. Statistically significant secondary eclipse depths and/or atmospheric brightness modulation amplitudes were measured for HIP65A, WASP-18, WASP-19, WASP-72, WASP-100, WASP-111, WASP-121, and WASP-122/KELT-14. For WASP-100b, we found marginal evidence that the brightest region of the atmosphere is shifted eastward away from the substellar point. We detected significant ellipsoidal distortion signals in the light curves of HIP65A, TOI-503, WASP-18, and WASP-30, with HIP65A, TOI-503 and WASP-18 also exhibiting Doppler boosting. The measured amplitudes of these signals agree with the predictions of theoretical models. Combining the optical secondary eclipse depths with previously published Spitzer 3.6 and 4.5{mu}m measurements, we derived dayside brightness temperatures and visible-light geometric albedos for a subset of the analyzed systems. We also calculated updated transit ephemerides combining the transit timings from the TESS light curves with previous literature values.
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- ID:
- ivo://CDS.VizieR/J/AJ/143/13
- Title:
- Light curves of AL Gem and BM Mon
- Short Name:
- J/AJ/143/13
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the CCD photometry of two Algol-type binaries, AL Gem and BM Mon, observed from 2008 November to 2011 January. With the updated Wilson-Devinney program, photometric solutions were deduced from their EA-type light curves. The mass ratios and fill-out factors of the primaries are found to be q_ph_=0.090(+/-0.005) and f_1_=47.3%(+/-0.3%) for AL Gem, and q_ph_=0.275(+/-0.007) and f_1_=55.4%(+/-0.5%) for BM Mon, respectively. By analyzing the O-C curves, we discovered that the periods of AL Gem and BM Mon change in a quasi-sinusoidal mode, which may possibly result from the light-time effect via the presence of a third body. Periods, amplitudes, and eccentricities of light-time orbits are 77.83(+/-1.17)yr, 0.0204(+/-0.0007)d, and 0.28(+/-0.02) for AL Gem and 97.78(+/-2.67)yr, 0.0175(+/-0.0006)d, and 0.29(+/-0.02) for BM Mon, respectively. Assumed to be in a coplanar orbit with the binary, the masses of the third bodies would be 0.29M_{sun}_ for AL Gem and 0.26M_{sun}_ for BM Mon. This kind of additional companion can extract angular momentum from the close binary orbit, and such processes may play an important role in multiple star evolution.
- ID:
- ivo://CDS.VizieR/J/AJ/147/35
- Title:
- Light curves of Algol-type binaries. VI. FR Ori
- Short Name:
- J/AJ/147/35
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- New photometry of the neglected eclipsing binary FR Orionis was obtained in 2012 November and December. Using the updated Wilson-Devinney program, the photometric elements were deduced from two-color light curves. The results indicate that this system is a semi-detached binary, with a mass ratio of 0.325(+/-0.002) and a fill-out factor of the primary of f_p_=73.5(+/-0.2)%. The oscillating light curves imply that FR Ori may be an oscillating EA (oEA)-type star with a rapidly pulsating, mass-accreting primary component. After we removed the theoretical light curves from the observations, Fourier analysis revealed that the more massive component possibly shows a {delta} Scuti type pulsation with four detected frequencies. The dominant frequency is f_1_=38.6c/day (i.e., P_puls_=37.3minutes), and the pulsation constant is Q=0.014days. Based on all available eclipsing times, the orbital period is undergoing a secular period increase with a rate of dP/dt=+8.85(+/-0.66)x10^-8^day/yr, which may be interpreted by mass transfer from the secondary to the primary. We expect that the more massive component will fill its Roche lobe due to mass transfer of the secondary. Therefore, the oEA star FR Ori may evolve into a contact configuration.
- 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.
- 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.
- 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.
- 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.
- 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.
- ID:
- ivo://CDS.VizieR/J/ApJ/754/136
- Title:
- Light curves of HD 149026b in 3.6-16um
- Short Name:
- J/ApJ/754/136
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The dayside of HD 149026b is near the edge of detectability by the Spitzer Space Telescope. We report on 11 secondary-eclipse events at 3.6, 4.5, 3x5.8, 4x8.0, and 2x16{mu}m plus three primary-transit events at 8.0{mu}m. The eclipse depths from jointly fit models at each wavelength are 0.040%+/-0.003% at 3.6{mu}m, 0.034%+/-0.006% at 4.5{mu}m, 0.044%+/-0.010% at 5.8{mu}m, 0.052%+/-0.006% at 8.0{mu}m, and 0.085%+/-0.032% at 16{mu}m. Multiple observations at the longer wavelengths improved eclipse-depth signal-to-noise ratios by up to a factor of two and improved estimates of the planet-to-star radius ratio (R_p_/R_{sstarf}_=0.0518+/-0.0006). We also identify no significant deviations from a circular orbit and, using this model, report an improved period of 2.8758916+/-0.0000014 days. Chemical-equilibrium models find no indication of a temperature inversion in the dayside atmosphere of HD 149026b. Our best-fit model favors large amounts of CO and CO_2_, moderate heat redistribution (f=0.5), and a strongly enhanced metallicity. These analyses use BiLinearly-Interpolated Subpixel Sensitivity (BLISS) mapping, a new technique to model two position-dependent systematics (intrapixel variability and pixelation) by mapping the pixel surface at high resolution. BLISS mapping outperforms previous methods in both speed and goodness of fit. We also present an orthogonalization technique for linearly correlated parameters that accelerates the convergence of Markov chains that employ the Metropolis random walk sampler.
- 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.
