Bibcode
Drake, A. J.; Graham, M. J.; Djorgovski, S. G.; Catelan, M.; Mahabal, A. A.; Torrealba, G.; García-Álvarez, D.; Donalek, C.; Prieto, J. L.; Williams, R.; Larson, S.; Christen sen, E.; Belokurov, V.; Koposov, S. E.; Beshore, E.; Boattini, A.; Gibbs, A.; Hill, R.; Kowalski, R.; Johnson, J.; Shelly, F.
Referencia bibliográfica
The Astrophysical Journal Supplement, Volume 213, Issue 1, article id. 9, 29 pp. (2014).
Fecha de publicación:
7
2014
Número de citas
417
Número de citas referidas
380
Descripción
We present ~47,000 periodic variables found during the analysis of 5.4
million variable star candidates within a 20,000 deg2 region
covered by the Catalina Surveys Data Release-1 (CSDR1). Combining these
variables with type ab RR Lyrae from our previous work, we produce an
online catalog containing periods, amplitudes, and classifications for
~61,000 periodic variables. By cross-matching these variables with those
from prior surveys, we find that >90% of the ~8000 known periodic
variables in the survey region are recovered. For these sources, we find
excellent agreement between our catalog and prior values of luminosity,
period, and amplitude as well as classification. We investigate the rate
of confusion between objects classified as contact binaries and type c
RR Lyrae (RRc's) based on periods, colors, amplitudes, metallicities,
radial velocities, and surface gravities. We find that no more than a
few percent of the variables in these classes are misidentified. By
deriving distances for this clean sample of ~5500 RRc's, we trace the
path of the Sagittarius tidal streams within the Galactic halo.
Selecting 146 outer-halo RRc's with SDSS radial velocities, we confirm
the presence of a coherent halo structure that is inconsistent with
current N-body simulations of the Sagittarius tidal stream. We also find
numerous long-period variables that are very likely associated within
the Sagittarius tidal stream system. Based on the examination of 31,000
contact binary light curves we find evidence for two subgroups
exhibiting irregular light curves. One subgroup presents significant
variations in mean brightness that are likely due to chromospheric
activity. The other subgroup shows stable modulations over more than a
thousand days and thereby provides evidence that the O'Connell effect is
not due to stellar spots.
Proyectos relacionados
Abundancias Químicas en Estrellas
La espectroscopía de estrellas nos permite determinar las propiedades y composiciones químicas de las mismas. A partir de esta información para estrellas de diferente edad en la Vía Láctea es posible reconstruir la evolución química de la Galaxia, así como el origen de los elementos más pesados que el boro, forjados principalmente en los interiores
Carlos
Allende Prieto