Wyniki wyszukiwania - Biblioteka Nauki

Nowa wersja platformy, zawierająca wyłącznie zasoby pełnotekstowe, jest już dostępna.
Przejdź na https://bibliotekanauki.pl

Ograniczanie wyników

3 Acta Astronomica

Znaleziono wyników: 3

Liczba wyników na stronie

Wyniki wyszukiwania

Wyszukiwano:
w słowach kluczowych: stars: variables: general

Sortuj według:

Ogranicz wyniki do:

The All Sky Automated Survey. Catalog of Variable Stars. V. Declinations 0° - +28° of the Northern Hemisphere

100%

Pojmański G. , Pilecki B. , Szczygieł D.

tom Vol. 55, No. 3

275--301

This paper contains the fifth part of the Catalog of Variable Stars created from the V-band photometric data collected by 9°×9° camera of the All Sky Automated Survey. Preliminary list of variable stars found in the fields located between declination 0° and +28° of the northern hemisphere is presented. 11 509 stars brighter than V=15 mag were found to be variable (2 482 eclipsing, 1 397 regularly pulsating, 318 Miras and 7 310 other stars). Automated algorithm taking into account light curve properties (period, Fourier coefficients) and other available data (2MASS colors, IRAS fluxes) was applied to roughly classify the objects. This paper concludes our preliminary efforts to detect variable stars brighter than V≈14 mag over the sky south of declination +28°. A short summary of the current ASAS Catalog of Variable Stars is presented and links to the on-line data are provided. All the photometric data are available over the INTERNET at http://www.astrouw.edu.pl/~gp/asas/asas.html or http://archive.princeton.edu/~asas

The Clusters AgeS Experiment (CASE). Variable stars in the field of the globular cluster NGC 362

100%

Rozyczka M. , Thompson I. B. , Narloch W. , Pych W. , Schwarzenberg-Czerny A.

tom Vol. 66, No. 3

307--332

The field of the globular cluster NGC 362 was monitored between 1997 and 2015 in a search for variable stars. BV light curves were obtained for 151 periodic or likely periodic variable stars, over a hundred of which are new detections. Twelve newly detected variable stars are proper-motion members of the cluster: two SX Phe and two RR Lyr pulsators, one contact binary, three detached or semi-detached eclipsing binaries, and four spotted variable stars. The most interesting objects among these are the binary blue straggler V20 with an asymmetric light curve, and the 8.1 d semidetached binary V24 located on the red giant branch of NGC 362, which is a Chandra X-ray source. We also provide substantial new data for 24 previously known variable stars.

Variable Star Population in the Open Cluster NGC 6819 Observed by the Kepler Spacecraft

100%

Sanjayan S. , Baran A. S. , Németh P. , Kinemuchi K.

tom Vol. 72, No. 4

267--295

We present the list of variable stars we found in the Kepler superstamp data covering approximately nine arcminutes from the central region of NGC 6819. This is a continuation of our earlier work. We classified the variable stars based on the variability type and we established their cluster membership based on the available Gaia Data Release 3 astrometry. Our search revealed 385 variable stars but only 128 were found to be cluster members. In the case of eclipsing and contact binaries we calculated the mid-times of eclipses and derived ephemerides. We searched for eclipse timing variation using the observed minus calculated diagrams. Only five objects show significant orbital period variation. We used isochrones calculated within the MESA Isochrones and Stellar Tracks project and derived the average age (2.54 Gyr), average distance (2.3 kpc) and iron content [Fe/H]=-0.01(2), of NGC 6819. We confirm this distance by the one derived from Gaia astrometry of the cluster members with membership probabilities greater than 0.9.