Search Publications
OGLE Collection of Galactic Cepheids
Soszyński, I.; Udalski, A.; Szymański, M. K. +10 more
We present here a new major part of the OGLE Collection of Variable Stars - OGLE Collection of Galactic Cepheids. The new dataset was extracted from the Galaxy Variability Survey images - a dedicated large-scale survey of the Galactic disk and outer bulge conducted by the OGLE project since 2013.
The OGLE collection contains 2721 Cepheids of …An Almanac of Predicted Microlensing Events for the 21st Century
Nielsen, M. B.; Bramich, D. M.
Using Gaia data release 2 (GDR2), we present an almanac of 2509 predicted microlensing events, caused by 2130 unique lens stars, that will peak between July 25, 2026 and the end of the century. This work extends and completes a thorough search for future microlensing events initiated by Bramich and Nielsen using GDR2. The almanac includes 161 lens…
Predicted Microlensing Events by Nearby Very-Low-Mass Objects: Pan-STARRS DR1 vs. Gaia DR2
Nielsen, M. B.; Bramich, D. M.
Microlensing events can be used to directly measure the masses of single field stars to a precision of ≈1-10%. The majority of direct mass measurements for stellar and sub-stellar objects typically only come from observations of binary systems. Hence microlensing provides an important channel for direct mass measurements of single stars. The Gaia …
Contemporaneous Broad-Band Photometry and Hα Observations of T Tau Stars
Montes, D.; Guillout, P.; Frasca, A. +2 more
In this paper we present the results of a simultaneous BVRI and Hα photometric monitoring, contemporaneous to medium-resolution spectroscopy of six T Tau stars in the Taurus-Auriga star forming region. We have characterized the Hα photometric system using synthetic templates and the contemporaneous spectra of the targets. We show that we can achie…
CCD Photometry, Light Curve Modeling and Period Analysis of the Overcontact Eclipsing Binary BN Ari
Alton, K. B.; Nelson, R. H.; Boyd, D. R. S.
We present photometric and spectroscopic data of BN Ari, a totally eclipsing variable star. 15 new times-of-minimum have been determined. These along with other published eclipse timings were used to update the linear ephemeris and evaluate changes in orbital periodicity. Radial velocity data along with a definitive classification spectrum are rep…
New Galactic Multi-Mode Cepheids from the ASAS-SN Survey
Catelan, M.; Hajdu, G.; Jurcsik, J.
A systematic search for multi-mode Cepheids using the database of the ASAS-SN survey has led to the detection of thirteen new double-mode and two triple-mode Cepheids in the Galactic disk. These discoveries have increased the number of Galactic disk multi-mode Cepheids by 33%. One of the new triple-mode variables pulsates simultaneously in the fun…
Roche Modeling and Evolutionary History of Multiple Low Mass Contact Binary Systems
Stępień, K.; Alton, K. B.
The Northern Sky Variable Survey (NSVS) has been a rich source of variable stars many of which have only been studied to a limited extent. Herein we describe five eclipsing binary systems that were first detected by the ROTSE-I telescope and ultimately shown to be low mass contact binaries. Photometric data (B, V and Ic) acquired from M…
On the Distance Measurements in the Thin Milky Way Disk
Krełowski, J.; Galazutdinov, G. A.; Strobel, A. +2 more
We present a test how far the direct, trigonometric parallax measurements and those, based on interstellar CaII H and K lines lead to distances to OB stars similar to those, based on spectrophotometrically determined ones. For this we use relatively nearby objects where the extinction effects are negligible. A test is based on observations of inte…
Spectroscopy of the Eclipsing Binary BD-00°2862. Possible Multiplicity
Kamiński, K.; Dimitrov, W.; Polińska, M. +2 more
We present the first spectroscopic analysis of the eclipsing binary BD-00°2862. The All Sky Automated Survey light curves yield orbital period of the system of 2.15 d. The shape of the light curve reveals that the components are almost spherical and the binary is detached. The eclipses depths show significant difference of the components' temperat…
GT Ursae Majoris AB - a Possible Quadruple System
Kamiński, K.; Dimitrov, W.; Polińska, M. +3 more
We present the first spectroscopic study of an eclipsing system GT UMa. Our spectra show that the main visual component A is a triple-lined star, which consists of a close eclipsing pair and a farther third component. Radial velocity measurements show evidence of reflex motion. We used Hipparcos and our own R-band light curves for the analysis. Th…