- ID:
- ivo://CDS.VizieR/J/A+A/511/A63
- Title:
- V1118 Ori UBVRIJHK outburst light curves
- Short Name:
- J/A+A/511/A63
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The accretion history of low-mass young stars is not smooth but shows spikes of accretion that can last from months and years to decades and centuries. Observations of young stars in outbursts can help us understand the temporal evolution of accreting stars and the interplay between the accretion disk and the stellar magnetosphere. The young late-type star V1118 Orionis was in outburst from 2005 to 2006. We followed the outburst with optical and near-infrared photometry. The X-ray emission was further probed with observations taken with XMM-Newton and Chandra during and after the outburst. In addition, we obtained mid-infrared photometry and spectroscopy with Spitzer at the peak of the outburst and in the post-outburst phase. The spectral energy distribution of V1118 Ori varied significantly over the course of the outburst. The optical flux showed the largest variations, most likely caused by enhanced emission by a hot spot. The hot spot dominated the optical and near-infrared emission at the peak of the outburst, while the disk emission dominated in the mid-infrared. The emission silicate feature in V1118 Ori is flat and does not vary in shape, but was slightly brighter at the peak of the outburst compared to the post-outburst spectrum. The X-ray flux correlated with the optical and infrared fluxes, indicating that accretion affected the magnetically active corona and the stellar magnetosphere. The thermal structure of the corona was variable with some indication of a cooling of the coronal temperature in the early phase of the outburst with a gradual return to normal values. Color-color diagrams in the optical and infrared showed variations during the outburst, with no obvious signature of reddening caused by circumstellar matter. Using Monte-Carlo realizations of star+disk+hotspot models to fit the spectral energy distributions in "quiescence" and at the peak of the outburst, we determined that the mass accretion rate varied from about 2.5x10^-7^M_{sun}_/yr to 1.0x10^-6^M_{sun}_/yr; in addition, the fractional area of the hotspot increased significantly. The multi-wavelength study of the V1118 Ori outburst helped us to understand the variations in spectral energy distributions and demonstrated the interplay between the disk and the stellar magnetosphere in a young, strongly accreting star.
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Search Results
- ID:
- ivo://CDS.VizieR/J/A+A/337/183
- Title:
- V1046 Ori uvby photometry and radial velocities
- Short Name:
- J/A+A/337/183
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report on a detailed spectroscopic and photometric study of V1046 Orionis undertaken to resolve uncertainties about the period(s) and causes of the spectroscopic and photometric variations of this helium-strong star. We have detected the lines of the secondary star in an extensive series of photographic and electronic spectra. This eliminates any doubt about the duplicity of this star. The orbital elements we derive from our measures of these spectra confirm the unusually large orbital eccentricity, e=0.433, for the short, P=18.65612d, orbital period. The line profiles, V/R ratio of the double H{alpha} emission, residuals of the primary radial velocities from the orbital velocity curve, brightness and colour of the object, magnetic field, and radio emission of this system all vary with a period of 0.9011836d. We tentatively follow earlier investigators in interpreting this as the rotational period of the primary and summarize the evidence of the phase shifts among the different phenomena, using the accurate value of the 0.9d period, to put tight constraints on any future model of these changes. We postpone our own attempt at a quantitative modelling of the variations with the 0.9d period for a separate study.
21173. V1162 Ori variations
- ID:
- ivo://CDS.VizieR/J/A+A/374/1056
- Title:
- V1162 Ori variations
- Short Name:
- J/A+A/374/1056
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- V1162 Ori is a delta Scuti star with variable period and amplitude. To analyse data acquired in the years 1998-2000, the data were subdivided in smaller subsets to take the amplitude and period variability into account. Four different ways of subdividing the data discussed in the paper are outlined in this table 2. A database containing the observations of V1162 Ori is in preparation; it will be published in the Journal of Astronomical data (http://www.vub.ac.be/STER/JAD/jad.htm).
- ID:
- ivo://voxastro.org/__system__/services/registry
- Title:
- VOXastro Data Center Registry
- Short Name:
- VOXAstro DC Reg
- Date:
- 06 Feb 2017 00:33:18
- Publisher:
- The staff at the VOXastro Data Center
- Description:
- The publishing registry for the VOXastro Data Center.
- ID:
- ivo://CDS.VizieR/J/AJ/161/102
- Title:
- VPDs and CMDs of Berkeley32, Berkeley98 and King23
- Short Name:
- J/AJ/161/102
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Using the photometric and kinematical data from Gaia Data Release 2, three old open clusters namely Berkeley32 (Be32), Berkeley98 (Be98), and King23 are investigated. The latter two of these clusters are poorly studied in the literature. The numbers of the most probable cluster members are 563, 260, and 114 for Be32, Be98, and King23, respectively, with membership probabilities higher than 80% and lying within the clusters limiting radii. Mean proper motions (PMs; {mu}_{alpha}_cos_{delta}_ and {mu}_{delta}_) of the clusters are determined as (-0.34{+/-}0.008, -1.60{+/-}0.006), (-1.34{+/-}0.007, -3.22{+/-}0.008), and (-0.46{+/-}0.009, -0.87{+/-}0.012)mas/yr. The errors mentioned in the PMs are the Gaussian fitting errors. The blue straggler stars (BSS) in all three old clusters were found to exhibit centralized radial distribution. The clusters' radii are determined as 9.4', 12.95', and 6.6' for Be32, Be98, and King23 using radial density profiles. Ages of the clusters determined by isochrone fitting are 4.90{+/-}0.22, 3.23{+/-}0.15, and 1.95{+/-}0.22Gyr. The errors given in the clusters ages are the internal errors. The mass function slopes are found to be flatter than Salpeter's value for all three clusters. All three clusters are found to be dynamically relaxed. Galactic orbits are derived for these clusters, which demonstrate that the studied clusters follow a circular path around the Galactic center.
21176. V505 Per BV light curves
- ID:
- ivo://CDS.VizieR/J/A+A/480/465
- Title:
- V505 Per BV light curves
- Short Name:
- J/A+A/480/465
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The orbit and fundamental physical parameters of the double-lined eclipsing binary V505 Per are derived by means of Echelle high-resolution and high S/N spectroscopy, and B, V photometry. In addition, effective temperatures, gravities, rotational velocities, and metallicities of both components are also obtained from atmospheric chi^2^ analysis, showing an excellent match with the results of the orbital solution.
21177. V873 Per BVR light curves
- ID:
- ivo://CDS.VizieR/J/other/NewA/36.50
- Title:
- V873 Per BVR light curves
- Short Name:
- J/other/NewA/36.
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a photometric study of a weak-contact binary V873 Per. New observations in BVR filter bands showed asymmetric light curves to be a negative type of the O'Connell effect, which can be described by magnetic activity of a cool spot on the more massive component. Our photometric solutions showed that V873 Per is a W-type with a mass ratio of q=2.504(+/-0.0029), confirming the results of Samec et al. (2009IBVS.5901....1S). The derived contact degree was found to be f=18.10%(+/-1.36%). Moreover, our analysis found the cyclic variation with the period of about 4yr that could be due to existence of the third companion in the system or the mechanism of magnetic activity cycle in the binary. While available data indicated that the long-term orbital period tends to be stable rather than decreasing.
- ID:
- ivo://CDS.VizieR/J/A+A/319/867
- Title:
- V436 Persei = 1 Persei byBV photometry
- Short Name:
- J/A+A/319/867
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Outline of a project aimed at testing the presence of rapid line-profile variations in the atmospheres of hot components of close binaries is presented and its first results are described. An analysis of new electronic spectra of the eclipsing binary V436 Per from three observatories and of photoelectric observations, obtained earlier by several authors, leads to a unique determination of all basic physical elements of this interesting object. The first practical application of a new method of spectral disentangling allowed us to obtain, for the first time, individual accurate line profiles of both binary components and to derive their rotational velocities and orbital radial-velocity curves. We also detected absorption sub-features travelling from blue to red accross the He I 6678 line profile, in a series of six spectra taken during one night. At least one of the components of V436 Per is, therefore, a new hot line-profile variable.
21179. V436 Persei UBV photometry
- ID:
- ivo://CDS.VizieR/J/A+A/408/611
- Title:
- V436 Persei UBV photometry
- Short Name:
- J/A+A/408/611
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- An analysis of new spectroscopic and photoelectric UBV observations, satisfactorily covering the whole orbital period of V436 Per, together with existing data allowed us to improve the knowledge of the basic physical characteristics of the binary and its components. In several aspects, our new results differ from the findings of Paper I (Harmanec et al., 1997, Cat. <J/A+A/319/867>) of this series: In particular, we found that it is the star eclipsed in the secondary minimum which is slightly more massive and larger than the optical primary. We also conclude that the apsidal advance -- if present at all -- is much slower than that estimated in a previous study. The orbital period might be increasing by 0.28 s per year but also this finding is very uncertain and needs verification by future observations. It is encouraging to note that two completely independent sets of programs for light-curve solutions lead to identical results. A notable finding is that both binary components rotate with very similar -- if not identical -- rotational periods of 1.45d and 1.40d, much shorter than what would correspond to a 10.9d spin-orbit synchronization period at periastron. Rapid line-profile changes reported earlier could not be confirmed from new, dedicated series of high-resolution and S/N spectra.
- ID:
- ivo://CDS.VizieR/J/PAZh/35/199
- Title:
- V,pg light curves of NSV 9159
- Short Name:
- J/PAZh/35/199
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have obtained 530 photographic magnitude estimates for the long-period classical Cepheid NSV 9159 (P=39d) in the plate collections of the Harvard Observatory and the Sternberg Astronomical Institute. Together with the currently available CCD observations from the ASAS-3 catalog, our data have allowed us to construct an O-C diagram spanning a time interval of 119 years. The O-C diagram has the shape of a parabola, which has made it possible to determine for the first time the quadratic light elements and to calculate the rate of evolutionary decrease in the period, 314.4(+/-7.3)s/yr, in agreement with the results of theoretical calculations for the second crossing of the instability strip. The available data reduced by the Eddington-Plakidis method do not reveal any noticeable random fluctuations in the period.
