- ID:
- ivo://CDS.VizieR/J/A+A/566/A101
- Title:
- V893 Sco long-term photometry
- Short Name:
- J/A+A/566/A101
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The cataclysmic variable V893 Sco is an eclipsing dwarf nova which, apart from outbursts with comparatively low amplitudes, exhibits a particularly strong variability during quiescence on timescales of days to seconds.The present study aims to update the outdated orbital ephemerides published previously, to investigate deviations from linear ephemerides, and to characterize non-random brightness variations in a range of timescales. Light curves of V893 Sco were observed on 39 nights, spanning a total time base of about 14 years. They contain 114 eclipses which were used to significantly improve the precision of the orbital period and to study long-term variations of the time of revolution. Oscillations and similar brightness variations were studied with Fourier techniques in the individual light curves. The orbital period exhibits long-term variations with a cycle time of 10.2 years. They can be interpreted as a light travel time effect caused by the presence of a giant planet with approximately 9.5 Jupiter masses in a 4.5AU orbit around V893 Sco. On some nights transient semi-periodic variations on timescales of several minutes can be seen which may be identified as quasi-periodic oscillations. However, it is difficult to distinguish whether they are caused by real physical mechanisms or if they are the effect of an accidental superposition of unrelated flickering flares. Simulations to investigate this question are presented.
Number of results to display per page
Search Results
- ID:
- ivo://CDS.VizieR/J/A+A/505/1283
- Title:
- (84922) 2003 VS2 differential light curve
- Short Name:
- J/A+A/505/1283
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We compile and analyze an extended database of light curve parameters scattered in the literature to search for correlations and study physical properties, including internal structure constraints.
- ID:
- ivo://CDS.VizieR/J/PAZh/37/691
- Title:
- V340 Ser and V448 Lac light curves
- Short Name:
- J/PAZh/37/691
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We analyze long-term UBV observations and ASAS-3 photometry for five candidates for protoplanetary nebulae - F and G supergiants with infrared excesses at high Galactic latitudes - V340 Ser, IRAS 05113+1347, V552 Pup, V448 Lac, and RV Col. These stars exhibit quasi-periodic multifrequency light variations caused by pulsations with characteristic time scales from 83 to 139 days, depending on the stellar temperature. Cooler stars undergo variations with larger amplitudes and periods. The variations at close frequencies with a period ratio of 1.03-1.09 are responsible for the amplitude modulation revealed for most program stars.
- ID:
- ivo://CDS.VizieR/J/ApJ/601/979
- Title:
- vsini of Orion low-mass stars
- Short Name:
- J/ApJ/601/979
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Projected rotational velocities (vsini) have been measured for a sample of 145 stars with masses between 0.4 and greater than 10M_{sun}_ (median mass 2.1M_{sun}_) located in the Orion star-forming complex. These measurements have been supplemented with data from the literature for Orion stars with masses as low as 0.1M_{sun}_.
- ID:
- ivo://CDS.VizieR/J/MNRAS/469/621
- Title:
- VST ATLAS white dwarf candidates cat.
- Short Name:
- J/MNRAS/469/621
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Sloan Digital Sky Survey (SDSS) has created a knowledge gap between the Northern and the Southern hemispheres, which is very marked for white dwarfs: Only ~15 per cent of the known white dwarfs are south of the equator. Here, we make use of the VLT Survey Telescope (VST) ATLAS survey, one of the first surveys obtaining deep, optical, multiband photometry over a large area of the southern skies, to remedy this situation. Applying the colour and proper-motion selection developed in our previous work on SDSS to the most recent internal data release (2016 April 25) of VST ATLAS, we created a catalogue of ~4200 moderately bright (g<=19), high-confidence southern white dwarf candidates, which can be followed up individually with both the large array of southern telescopes or in bulk with ESO's forthcoming multi-object spectrograph 4MOST.
8066. V410 Tau
- ID:
- ivo://CDS.VizieR/J/A+AS/107/9
- Title:
- V410 Tau
- Short Name:
- J/A+AS/107/9
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- (no description available)
- ID:
- ivo://CDS.VizieR/J/AcA/70/219
- Title:
- V1241 Tau and GQ Dra light curves
- Short Name:
- J/AcA/70/219
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present new photometric and spectroscopic observations and analyses for the eclipsing binary systems V1241 Tau and GQ Dra. Our photometric light and radial velocity curves analyses combining with the TESS light curves show that both are conventional semi--detached binary systems. Their absolute parameters are also derived. We present the O-C analyses of the systems and we propose the most possible orbital period modulating mechanisms. Furthermore, Fourier analyses are applied to the photometric residual data of the systems to check for the pulsational behavior of the components. We conclude that the primary component of the system GQ Dra is a delta Sct type pulsator with a dominant pulsation frequency of 18.58d^-1^ based on our B filter residual light curve although it can not be justified by 30-minute cadence TESS data. No satisfactory evidence of pulsational behaviour for V1241 Tau was verified. Finally, the evolutionary tracks of the components of both systems are calculated, while their locations within evolutionary diagrams are compared with other Algol-type systems.
- ID:
- ivo://CDS.VizieR/J/A+A/510/A91
- Title:
- V1130 Tau differential uvby light curves
- Short Name:
- J/A+A/510/A91
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Double-lined, detached eclipsing binaries are our main source for accurate stellar masses and radii. This paper is the first in a series with focus on the upper half of the main-sequence band and tests of 1-2M_{sun}_ evolutionary models. We aim to determine absolute dimensions and abundances for the detached eclipsing binary V1130 Tau, and to perform a detailed comparison with results from recent stellar evolutionary models.
- ID:
- ivo://CDS.VizieR/J/A+A/582/A113
- Title:
- V1184 Tauri UBVRI light curves
- Short Name:
- J/A+A/582/A113
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- V1184 Tau (CB 34V) lies in the field of the Bok globule CB 34 and was discovered as a large amplitude variable in 1993. According to the first hypothesis of the variability of the star, it is a FU Orionis candidate erupted between 1951 and 1993. During subsequent observations, the star manifests large amplitude variability interpreted as obscuration from circumstellar clouds of dust. We included V1184 Tau (CB 34V) in our target list of highly variable pre-main-sequence stars to determine the reasons for the variations in the brightness of this object. Data from BVRI photometric observations of V1184 Tau were performed in two observatories with two medium-sized and two small telescopes. Our results indicate that during periods of maximum light the star shows characteristics typical of T Tauri stars. During the observed deep minimum in brightness, however, V1184 Tau is rather similar to UX Orionis objects. The deep drop in brightness magnitude diagrams is also confirmation of obscuration from circumstellar clouds of dust as a reason for the large amplitude variability in the brightness.
- ID:
- ivo://CDS.VizieR/J/ApJ/810/157
- Title:
- V471 Tau system: RVs and BVRI LCs
- Short Name:
- J/ApJ/810/157
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- V471 Tauri, a white dwarf-red dwarf eclipsing binary (EB) in the Hyades, is well known for stimulating development of common envelope theory, whereby novae and other cataclysmic variables form from much wider binaries by catastrophic orbit shrinkage. Our evaluation of a recent imaging search that reported negative results for a much postulated third body shows that the object could have escaped detection or may have actually been seen. The balance of evidence continues to favor a brown dwarf companion about 12 AU from the EB. A recently developed algorithm finds unified solutions from three data types. New radial velocities (RVs) of the red dwarf and BVRcIc light curves are solved simultaneously along with white dwarf and red dwarf RVs from the literature, uvby data, the Microvariability and Oscillations of Stars mission light curve, and 40 years of eclipse timings. Precision-based weighting is the key to proper information balance among the various data sets. Timewise variation of modeled starspots allows unified solution of multiple data eras. Light-curve amplitudes strongly suggest decreasing spottedness from 1976 to about 1980, followed by approximately constant spot coverage from 1981 to 2005. An explanation is proposed for lack of noticeable variation in 1981 light curves, in terms of competition between spot and tidal variations. Photometric-spectroscopic distance is estimated. The red dwarf mass comes out larger than normal for a K2 V star, and even larger than adopted in several structure and evolution papers. An identified cause for this result is that much improved red dwarf RV curves now exist.
