- ID:
- ivo://CDS.VizieR/J/PASP/133/H4201
- Title:
- Times of maxima for 23 delta Scuti stars
- Short Name:
- J/PASP/133/H4201
- Date:
- 17 Jan 2022 00:25:09
- Publisher:
- CDS
- Description:
- The multi-color CCD photometric study of 27 delta Scuti stars is presented. By using approximately three years of photometric observations, we obtained the times of maxima and magnitude changes during the observation time interval for each star. The ephemeris of our delta Scuti star was calculated based on the Markov Chain Monte Carlo (MCMC) method using the observed times of maxima and the period of star' oscillations. We used the Gaia EDR3 parallaxes to calculate the luminosities and also the absolute magnitudes of these delta Scuti stars. The fundamental physical parameters of all studied stars, such as mass and radius, were estimated. We determined the pulsation modes of the stars based on the pulsation constants. Moreover, the period-luminosity relation of delta Scuti stars was investigated and discussed. Then, by using a machine learning classification, new P-L relations for fundamental and overtone modes are presented.
Number of results to display per page
Search Results
- ID:
- ivo://CDS.VizieR/J/PASP/125/639
- Title:
- Times of Maxima for the SX Phe star BL Cam
- Short Name:
- J/PASP/125/639
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A total of 73 new times of maximum light for BL Cam were observed through the years 2005 to 2011, which are combined with 1392 times of maxima taken from literature. A more accurate period of 0.039097912(1) days was found, and an updated linear ephemeris is presented. This newly presented linear ephemeris was used to calculate revised O minus C values, which were fitted with a parabolic curve to measure the rate of change of the pulsation period, found to be (1/P)(dP/dt)=1.37+/-0.02x10^-7yr^-1. Although the parabolic fit has a physical interpretation, it is noted that a cubic more appropriately fits the behavior of the O minus C diagram.
- ID:
- ivo://CDS.VizieR/J/AJ/144/92
- Title:
- Times of maximum light for the SX Phe star XX Cyg
- Short Name:
- J/AJ/144/92
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Time-series photometric observations were made for the SX Phoenicis star XX Cyg between 2007 and 2011 at the Xinglong Station of National Astronomical Observatories of China. With the light curves derived from the new observations, we do not detect any secondary maximum in the descending portion of the light curves of XX Cyg, as reported in some previous work. Frequency analysis of the light curves confirms a fundamental frequency f_0_=7.4148cycles/day and up to 19 harmonics, 11 of which are newly detected. However, no secondary mode of pulsation is detected from the light curves. The O-C diagram, produced from 46 newly determined times of maximum light combined with those derived from the literature, reveals a continuous period increase with the rate of (1/P)(dP/dt)=1.19(13)x10^-8^/yr. Theoretical rates of period change due to the stellar evolution were calculated with a modeling code. The result shows that the observed rate of period change is fully consistent with period change caused by evolutionary behavior predicted by standard theoretical models.
- ID:
- ivo://CDS.VizieR/J/A+A/562/A90
- Title:
- Times of maximum light of Blazhko RRab stars
- Short Name:
- J/A+A/562/A90
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Period study of 321 fundamental mode RR Lyrae type stars (RRab), which had appropriate data in ASAS and SuperWASP surveys, was performed to complement and extend the list of known Blazhko stars in galactic field with bright stars up to 12.5 mag in maximum light. An individual approach was applied to each studied star. Permanent visual supervision was maintained to each procedure in data analysis (data cleaning, frequency spectra examination) to avoid missing any possible sign of the Blazhko effect. Period analysis was performed using Period04 software.
- ID:
- ivo://CDS.VizieR/J/AJ/157/87
- Title:
- Times of minima for 21 early-type SMC eccentric EBs
- Short Name:
- J/AJ/157/87
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the apsidal motion and light-curve analyses of 21 eccentric eclipsing binaries located in the Small Magellanic Cloud. Most of these systems have never been studied before, hence their orbital and physical properties as well as the apsidal motion parameters are given here for the first time. All the systems are of early spectral type, having orbital periods up to 4 days. The apsidal motion periods were derived to be from 7.2 to 200 yr (OGLE-SMC-ECL-2194 having the shortest apsidal period among known main-sequence systems). The orbital eccentricities are usually rather mild (median of about 0.06), the maximum eccentricity being 0.33. For the period analysis using O-C diagrams of eclipse timings, in total 951 minima were derived from survey photometry as well as our new data. Moreover, six systems show some additional variation in their O-C diagrams, which should indicate the presence of hidden additional components in them. According to our analysis these third-body variations have periods from 6.9 to 22 yr.
- ID:
- ivo://CDS.VizieR/J/AcA/62/97
- Title:
- Times of minima for 13 eclipsing binaries
- Short Name:
- J/AcA/62/97
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Main aim of this paper is the first light curve and apsidal motion analysis of thirteen eccentric eclipsing binaries and determination of their basic physical properties. All of the systems were studied by the method of period analysis of times of minima and the light curve analysis. Many new times of minima were derived and collected from the data obtained by the automatic, robotic or satellite telescopes. This allows us to study the apsidal motion in these systems in detail for the first time. From the light curve analysis the first rough estimations of the physical properties of these systems were obtained.
- ID:
- ivo://CDS.VizieR/J/AJ/150/183
- Title:
- Times of minima for 18 LMC eclipsing binaries
- Short Name:
- J/AJ/150/183
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- New CCD observations for 13 eccentric eclipsing binaries from the Large Magellanic Cloud were carried out using the Danish 1.54 m telescope located at the La Silla Observatory in Chile. These systems were observed for their times of minimum and 56 new minima were obtained. These are needed for accurate determination of the apsidal motion. Besides that, in total 436 times of minimum were derived from the photometric databases OGLE and MACHO. The O - C diagrams of minimum timings for these B-type binaries were analyzed and the parameters of the apsidal motion were computed. The light curves of these systems were fitted using the program PHOEBE, giving the light curve parameters. We derived for the first time relatively short periods of the apsidal motion ranging from 21 to 107 years. The system OGLE-LMC-ECL-07902 was also analyzed using the spectra and radial velocities, resulting in masses of 6.8 and 4.4 M_{sun}_ for the eclipsing components. For one system (OGLE-LMC-ECL-20112), the third-body hypothesis was also used to describe the residuals after subtraction of the apsidal motion, resulting in a period of about 22 years. For several systems an additional third light was also detected, which makes these systems suspect for triplicity.
- ID:
- ivo://CDS.VizieR/J/A+A/572/A71
- Title:
- Times of minima for 18 SMC eclipsing binaries
- Short Name:
- J/A+A/572/A71
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Danish 1.54-meter telescope at the La Silla observatory was used for photometric monitoring of selected eccentric eclipsing binaries located in the Small Magellanic Cloud. The new times of minima were derived for these systems, which are needed for accurate determination of the apsidal motion. Moreover, many new times of minima were derived from the photometric databases OGLE and MACHO. Eighteen early-type eccentric-orbit eclipsing binaries were studied. Their O-C diagrams of minima timings were analysed and the parameters of the apsidal motion were obtained. The light curves of these eighteen binaries were analysed using the program PHOEBE, giving the light curve parameters. For several systems, the additional third light also was detected.
- ID:
- ivo://CDS.VizieR/J/A+A/558/A71
- Title:
- Times of minima for 1SWASP J234401.81-212229.1
- Short Name:
- J/A+A/558/A71
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report our investigation of 1SWASP J234401.81-212229.1, a variable with a 18461.6s period. After identification in a 2011 search of the SuperWASP archive for main-sequence eclipsing binary candidates near the distribution's short-period limit of ~0.20d, it was measured to be undergoing rapid period decrease in our earlier work, though later observations supported a cyclic variation in period length. Spectroscopic data obtained in 2012 with the Southern African Large Telescope did not, however, support the interpretation of the object as a normal eclipsing binary. Here, we consider three possible explanations consistent with the data: a single-star oblique rotator model in which variability results from stable cool spots on opposite magnetic poles; a two-star model in which the secondary is a brown dwarf; and a three-star model involving a low-mass eclipsing binary in a hierarchical triple system. We conclude that the latter is the most likely model.
- ID:
- ivo://CDS.VizieR/J/other/IBVS/5502
- Title:
- Times of minima of eclipsing binaries in 2003
- Short Name:
- J/other/IBVS/550
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Times of minima for a number of neglected eclipsing binaries are presented.
