- ID:
- ivo://CDS.VizieR/J/MNRAS/407/497
- Title:
- BVRI light curves of KZ Pav
- Short Name:
- J/MNRAS/407/497
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present results from analysing new spectroscopic and photometric observations of the KZ Pav (IDS 20490-7048 A-BC) multiple system. High-resolution spectra were taken at the Mt John University Observatory in 2007 and 2008. Radial velocities for the close binary were determined from cross-correlation and spectral disentangling methods.
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- ID:
- ivo://CDS.VizieR/J/A+A/601/A133
- Title:
- BVRI light curves of 3 massive binaries
- Short Name:
- J/A+A/601/A133
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The role of mass and momentum exchanges in close massive binaries is very important in the subsequent evolution of the components. Such exchanges produce several observational signatures such as asynchronous rotation and altered chemical compositions, that remain after the stars detach again. We investigated these effects for the close O-star binary LSS 3074 (O4f+O6-7:(f):), which is a good candidate for a past Roche lobe overflow (RLOF) episode because of its very short orbital period, P=2.185-days, and the luminosity classes of both components. We determined a new orbital solution for the system. We studied the photometric light curves to determine the inclination of the orbit and Roche lobe filling factors of both stars. Using phase-resolved spectroscopy, we performed the disentangling of the optical spectra of the two stars. We then analysed the reconstructed primary and secondary spectra with the CMFGEN model atmosphere code to determine stellar parameters, such as the effective temperatures and surface gravities, and to constrain the chemical composition of the components. We confirm the apparent low stellar masses and radii reported in previous studies. We also find a strong overabundance in nitrogen and a strong carbon and oxygen depletion in both primary and secondary atmospheres, together with a strong enrichment in helium of the primary star. We propose several possible evolutionary pathways through a RLOF process to explain the current parameters of the system. We confirm that the system is apparently in overcontact configuration and has lost a significant portion of its mass to its surroundings. We suggest that some of the discrepancies between the spectroscopic and photometric properties of LSS 3074 could stem from the impact of a strong radiation pressure of the primary.
- ID:
- ivo://CDS.VizieR/J/ApJ/694/1237
- Title:
- BVRI light curves of NGC 247 Cepheids
- Short Name:
- J/ApJ/694/1237
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report VRI CCD observations of nine Cepheids in the South Polar (Sculptor) Group spiral galaxy NGC 0247. Periods of these Cepheids range from 20 to 70 days. Over the past 20 years, the brightest Cepheid in our sample, NGC 0247:[MF09] C1, has decreased its period by 6%, faded by 0.8mag in the V band, and become bluer by 0.23mag in (V-I).
- ID:
- ivo://CDS.VizieR/J/MNRAS/454/123
- Title:
- BVRI light curves of Nova V723 Cas
- Short Name:
- J/MNRAS/454/123
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present optical spectroscopy collected at seven epochs and BVRcIc photometry obtained at 1227 epochs of nova V723 Cas, covering the time interval between 2007 and 2015. The mean magnitude during this period, stable at ~3mag brighter than in quiescence, and the continuous presence of strong [FeX] and other high-ionization emission lines, indicates that the nuclear burning at the surface of the white dwarf is continuing 20-years past the initial outburst. The light curve shows a large amplitude (2mag) orbital modulation, which is governed by the visibility of the irradiated side of the secondary star. Our observations do not confirm the reported increase with time of the orbital period of V723 Cas, a period of P=16.638383+/-0.000025h satisfying equally well all available observations in all bands. Our observations also do not confirm the presence of an additional periodicity around P=15.2397h from which V723 Cas was classified as an intermediate-polar system.
- ID:
- ivo://CDS.VizieR/J/A+A/645/A137
- Title:
- BVRI light curves of PG 1553+113
- Short Name:
- J/A+A/645/A137
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The TeV BL Lac object PG 1553+113 is one of the primary candidates for a binary supermassive black hole system. We study the flux and spectral variability of PG 1553+113 on intra-night to long-term timescales using (i) BVRI data collected over 76 nights from January 2016 to August 2019 involving nine optical telescopes and (ii) historical VR data (including ours) obtained for the period from 2005 to 2019. We analysed the light curves using various statistical tests, fitting and cross-correlation techniques, and methods for the search for periodicity. We examined the colour-magnitude diagrams before and after the corresponding light curves were corrected for the long-term variations. Our intra-night monitoring, supplemented with literature data, result in a low duty cycle of ~(10-17)%. In April 2019, we recorded a flare, which marks the brightest state of PG 1553+113 for the period from 2005 to 2019: R~13.2mag. This flare is found to show a clockwise spectral hysteresis loop on its VR colour-magnitude diagram and a time lag in the sense that the V-band variations lead the R-band ones. We obtain estimates of the radius, the magnetic field strength, and the electron energy that characterize the emission region related to the flare. We find a median period of (2.21+/-0.04) years using the historical light curves. In addition, we detect a secondary period of about 210 days using the historical light curves corrected for the long-term variations. We briefly discuss the possible origin of this period.
- ID:
- ivo://CDS.VizieR/J/AJ/136/1846
- Title:
- BVRI light curves of S5 0716+714
- Short Name:
- J/AJ/136/1846
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the optical photometry (B, V, R, and I) of the BL Lac object S5 0716+714 (z>0.3), which were observed with the 1m telescope at Yunnan Astronomical Observatory and the 1.56m telescope at Shanghai Astronomical Observatory from 2001 February to 2006 April.
- ID:
- ivo://CDS.VizieR/J/other/NewA/20.30
- Title:
- BVRI light curves of 3 SN
- Short Name:
- J/other/NewA/20.
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Accurate and densely populated BVRcIc lightcurves of supernovae SN 2011fe in M101, SN 2012aw in M95 and SN 2012cg in NGC 4424 are presented and discussed. The SN 2011fe lightcurves span a total range of 342 days, from 17 days pre- to 325 days post-maximum. The observations of both SN 2012aw and SN 2012cg were stopped by solar conjunction, when the objects were still bright. The lightcurve for SN 2012aw covers 92 days, that of SN 2012cg spans 44 days. Time and brightness of maxima are measured, and from the lightcurve shapes and decline rates the absolute magnitudes are obtained, and the derived distances are compared to that of the parent galaxies. The color evolution and the bolometric lightcurves are evaluated in comparison with those of other well observed supernovae, showing no significant deviations.
- ID:
- ivo://CDS.VizieR/J/PASP/122/1
- Title:
- BVRI light curves of SN 2007gi
- Short Name:
- J/PASP/122/1
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present optical photometry and spectra for the Type Ia supernova (SN Ia) 2007gi in the nearby galaxy NGC 4036. SN 2007gi is characterized by extremely high-velocity (HV) features of the intermediate-mass elements (Si, Ca, and S), with expansion velocities (v_exp_) approaching 15500km/s near-maximum brightness (compared to 10600km/s for SNe Ia with normal v_exp_). SN 2007gi reached a B-band peak magnitude of 13.25+/-0.04mag with a decline rate of {DELTA}m15(B)(true)=1.33+/-0.09mag. The B-band light curve of SN 2007gi demonstrated an interesting two-stage evolution during the nebular phase, with a decay rate of 1.16+/-0.05mag/(100days) during t=60-90days and 1.61+/-0.04mag/(100days) thereafter. Such behavior was also observed in the HV SN Ia 2006X, and might be caused by the interaction between supernova ejecta and circumstellar material (CSM) around HV SNe Ia. Based on a sample of a dozen well-observed R band (or unfiltered) light curves of SNe Ia, we confirm that the HV events may have a faster rise time to maximum than those with normal v_exp_.
- ID:
- ivo://CDS.VizieR/J/AJ/145/99
- Title:
- BVRI light curves of SN 2003ie
- Short Name:
- J/AJ/145/99
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present new photometric observations of supernova (SN) 2003ie starting one month before discovery, obtained serendipitously while observing its host galaxy. With only a weak upper limit derived on the mass of its progenitor (<25M_{sun}_) from previous pre-explosion studies, this event could be a potential exception to the "red supergiant (RSG) problem" (the lack of high-mass RSGs exploding as Type IIP SNe). However, this is true only if SN2003ie was a Type IIP event, something which has never been determined. Using recently derived core-collapse SN light-curve templates, as well as by comparison to other known SNe, we find that SN2003ie was indeed a likely Type IIP event. However, with a plateau magnitude of ~-15.5mag, it is found to be a member of the faint Type IIP class. Previous members of this class have been shown to arise from relatively low-mass progenitors (<12M_{sun}_). It therefore seems unlikely that this SN had a massive RSG progenitor. The use of core-collapse SN light-curve templates is shown to be helpful in classifying SNe with sparse coverage. These templates are likely to become more robust as large homogeneous samples of core-collapse events are collected.
- ID:
- ivo://CDS.VizieR/J/MNRAS/383/1485
- Title:
- BVRI light curves of SN 2003jd
- Short Name:
- J/MNRAS/383/1485
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The results of a worldwide coordinated observational campaign on the broad-lined Type Ic supernova (SN Ic) 2003jd are presented. In total, 74 photometric data points and 26 spectra were collected using 11 different telescopes. SN 2003jd is one of the most luminous SN Ic ever observed. A comparison with other Type Ic supernovae (SNe Ic) confirms that SN 2003jd represents an intermediate case between broad-line events (2002ap, 2006aj) and highly energetic SNe (1997ef, 1998bw, 2003dh, 2003lw), with an ejected mass of M_ej_=3.0+/-1M_{sun}_ and a kinetic energy of E_k_(tot)=7^+3^_-2_x10^51^erg. SN 2003jd is similar to SN 1998bw in terms of overall luminosity, but it is closer to SNe 2006aj and 2002ap in terms of light-curve shape and spectral evolution. The comparison with other SNe Ic suggests that the V-band light curves of SNe Ic can be partially homogenized by introducing a time-stretch factor. Finally, because of the similarity of SN 2003jd to the SN 2006aj/XRF 060218 event, we discuss the possible connection of SN 2003jd with a gamma-ray burst (GRB).
