- 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.
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Search Results
- 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/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.
- 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.
- ID:
- ivo://CDS.VizieR/J/ApJS/219/25
- Title:
- Light curves of RR Lyrae stars in M3 (NGC5272)
- Short Name:
- J/ApJS/219/25
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The overtone and multi-mode RR Lyrae stars in the globular cluster M3 are studied using a 200 day long, B,V, and l_c_ time-series photometry obtained in 2012. 70% of the 52 overtone variables observed show some kind of multi-periodicity (with additional frequency at f_0.61_=f_1O_/0.61 frequency ratio, Blazhko effect, double/multi-mode pulsation, and period doubling). A signal at the 0.587 frequency ratio to the fundamental-mode frequency is detected in the double-mode star, V13, which may be identified as the second radial overtone mode. If this mode identification is correct, then V13 is the first RR Lyrae star showing triple-mode pulsation of the first three radial modes. Either the Blazhko effect or the f_0,61_ frequency (or both of these phenomena) appears in seven double-mode stars. The P_1O_/P_F_ period ratio of RRd stars showing the Blazhko effect are anomalous. A displacement of the main frequency component at the fundamental mode with the value of modulation frequency (or its half), is detected in three Blazhko RRd stars that are parallel with the appearance of the overtone-mode pulsation. The f_0.61_ frequency appears in RRc stars that lie at the blue side of the double-mode region and in RRd stars, raising the suspicion that its occurrence may be connected to double-mode pulsation. The changes of the Blazhko and double-mode properties of the stars are also reviewed using the recent and archive photometric data.
- ID:
- ivo://CDS.VizieR/J/MNRAS/478/4590
- Title:
- Light curves of RR Lyrae variables in M31
- Short Name:
- J/MNRAS/478/4590
- Date:
- 10 Dec 2021 13:45:59
- Publisher:
- CDS
- Description:
- We present an analysis of M31 RR Lyrae stars in six different fields using archival imaging from the Hubble Space Telescope. Published data for M31, M33, and several M31 dwarf spheroidal galaxies are also used to study the global properties of RR Lyrae in these systems. From the properties of RR Lyrae stars, we found that the majority of M31 and M33 RRLs are of Oosterhoff I (OoI),while those in M31 dSphs are of Oosterhoff intermediate. The main parameter affecting these Oosterhoff types is likely to be metallicity. Metallicity also plays a role in the lack of RRLs in the high amplitude short period(HASP, defined as those with P<=0.48 and A_V_>=0.75mag) variables in M31 dSphs. This difference in the properties of RRLs between their parent galaxy and satellites, as well as the lack of RRLs in the HASP region in dSphs can also be observed in the Milky Way (MW). Therefore, systems like these dSphs are unlikely to be the main building blocks of the M31 and MW halo.
- ID:
- ivo://CDS.VizieR/J/AJ/112/2408
- Title:
- Light Curves of 29 SNe
- Short Name:
- J/AJ/112/2408
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- BV(RI)_KC_ (see Bessel, 1990PASP..102.1181B) light curves are presented for 27 type Ia supernovae discovered during the course of the Calan/Tololo Survey and for two other SNe Ia observed during the same period. Estimates of the maximum light magnitudes in the B, V, and I bands and the initial decline rate parameter {Delta}m_15_(B) are also given.
- ID:
- ivo://CDS.VizieR/J/ApJ/700/331
- Title:
- Light curves of type Ia supernovae (CfA3)
- Short Name:
- J/ApJ/700/331
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present multiband photometry of 185 type-Ia supernovae (SNe Ia), with over 11500 observations. These were acquired between 2001 and 2008 at the F. L. Whipple Observatory of the Harvard-Smithsonian Center for Astrophysics (CfA). This sample contains the largest number of homogeneously observed and reduced nearby SNe Ia (z<~0.08) published to date. It more than doubles the nearby sample, bringing SN Ia cosmology to the point where systematic uncertainties dominate. Our natural system photometry has a precision of <~0.02mag in BVRIr'i' and <~0.04 mag in U for points brighter than 17.5mag. We also estimate a systematic uncertainty of 0.03mag in our SN Ia standard system BVRIr'i' photometry and 0.07mag for U. Comparisons of our standard system photometry with published SN Ia light curves and comparison stars, where available for the same SN, reveal agreement at the level of a few hundredths mag in most cases. We find that 1991bg-like SNe Ia are sufficiently distinct from other SNe Ia in their color and light-curve-shape/luminosity relation that they should be treated separately in light-curve/distance fitter training samples.
- ID:
- ivo://CDS.VizieR/J/A+A/523/A7
- Title:
- Light curves of type Ia supernovae in SNLS
- Short Name:
- J/A+A/523/A7
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present photometric properties and distance measurements of 252 high redshift Type Ia supernovae (0.15<z<1.1) discovered during the first three years of the Supernova Legacy Survey (SNLS). These events were detected and their multi-colour light curves measured using the MegaPrime/MegaCam instrument at the Canada-France-Hawaii Telescope (CFHT), by repeatedly imaging four one-square degree fields in four bands. Follow-up spectroscopy was performed at the VLT, Gemini and Keck telescopes to confirm the nature of the supernovae and to measure their redshifts.
