相关论文: A new absolute magnitude calibration with 2MASS fo…
The period-luminosity (P-L) relation for Cepheid variables is important in modern astrophysics. In this work, we present the multi-band P-L relations derived from the Large Magellanic Cloud (LMC) and Small Magellanic Cloud (SMC) Cepheids,…
Mira variables are useful distance indicators, due to their high luminosities and well-defined period-luminosity relation. We select 1863 Miras from SAAO and MACHO observations to examine their use as distance estimators in the Milky Way.…
We present a determination of precise fundamental physical parameters of twenty detached, double- lined, eclipsing binary stars in the Large Magellanic Cloud (LMC) containing G- or early K-type giant stars. Eleven are new systems, the…
Gaia DR3 parallaxes are used to calibrate preliminary period--luminosity relations of O-rich Mira variables in the 2MASS $J$, $H$ and $K_s$ bands using a probabilistic model accounting for variations in the parallax zeropoint and…
We point out that the absolute magnitude of the Galactic Cepheids, which have been used for local calibrations for Cepheid period-luminosity relation, shows an unexpectedly large metal abundance effect. This indicates that either Cepheids…
A new calibration of the Mv-W(OI 7774) relationship has been calculated using better estimates of reddenings and distances to a sample of 27 calibrator stars of A-G spectral types, based on accurate parallaxes and proper motions from the…
We present the photometric analysis of three ultra-short period total eclipsing binaries in contact configuration, CRTS_J172718.0+431624, OGLE-BLG-ECL-000104, and OGLE-BLG-ECL-000012, mined from massive astronomical surveys. Using the…
A critical analysis of three methods of estimating distances to cataclysmic variables (CVs) is performed. These methods, by Ak et al., Beuermann, and Knigge, all use near-infrared (JHK or Ks) magnitudes and the Barnes-Evans relation. We…
Time-resolved optical photometry, complemented by TESS data and long-term survey light curves, reveals that the transient object CRTS SSS100505 J093417-174421 is an eclipsing novalike cataclysmic variable of the VY~Scl subtype, with an…
We critically examine the basic paradigm for the origin of the 2-3 hr period gap in cataclysmic variables (CVs). We carry out an extensive population synthesis study of CVs starting from ~ 3 x 10^6 primordial binaries, and evolving some ~ 2…
More than two hundred classical cepheids were measured by the Hipparcos astrometric satellite, making possible a geometrical calibration of the cepheid distance scale. However, the large average distance of even the nearest cepheids…
We present a detailed statistical analysis of possible non-linearities in the Period-Luminosity (P-L), Period-Wesenheit (P-W) and Period-Color (P-C) relations for Cepheid variables in the LMC at optical ($VI$) and near-infrared ($JHK_{s}$)…
Thirty eight long-period (P>10 days), apparently contact binary stars discovered by the OGLE-II project in the SMC appear to be Beta Lyrae-type systems with ellipsoidal variations of the cool components dominating over eclipse effects in…
The mass-loss rate of donor stars in cataclysmic variables (CVs) is of paramount importance in the evolution of short-period CVs. Observed donors are oversized in comparison with those of isolated single stars of the same mass, which is…
New relationships between the orbital period and some parameters of W Ursae Majoris (W UMa) type systems are presented in this study. To investigate the relationships, we calculated the absolute parameters of a sample of 118 systems. For…
In this paper, we derive the period-luminosity (PL) relation for Galactic Cepheids with recent independent distance measurements from open cluster, Barnes-Evans surface brightness, interferometry and HST astrometry techniques. Our PL…
Hipparcos trigonometrical parallaxes of Mira-type variables have been combined with ground-based angular diameter measurements to derive linear diameters. Of eight stars with ground-based data, six have diameters indicating overtone…
Photometric data for 593 Cepheids in the LMC, measured by Udalski et al. in the OGLE survey, augmented by 92 longer period Cepheids from other sources, are analyzed for the P-C and P-L relations, and for the variations of amplitude, light…
We have obtained differential time series photometry of the cataclysmic variable GS Pavonis over a timespan of 2 years. These show that this system is deeply eclipsing (~2-3.5 mag) with an orbital period of 3.72 hr. The eclipse depth and…
We present high-speed photometry covering one eclipse of the cataclysmic variable system 1RXS J180834.7+101041. The data are modelled as arising from a close binary system containing a low-mass stars filling its Roche lobe plus a white…