Rr Lyrae Stars in the Macho Database
نویسنده
چکیده
The MACHO Project has catalogued 8000 RR Lyrae stars in the Large Magellanic Cloud, 1800 in the Galactic bulge, and 50 in the Sgr dwarf galaxy. These variables are excellent distance indicators, and are used as tools to study the structure of the Large Magellanic Cloud and the bulge. The large datasets also probe uncommon pulsation modes. A number of double-mode RR Lyrae stars (RRd) are found in the Large Magellanic Cloud sample. These stars provide important clues for understanding the formation and evolution of the inner Galaxy, the Large Magellanic Cloud and the Sgr dwarf galaxy. A large number of second overtone pulsators (RRe) are found in the LMC and bulge. Finally, the RR Lyrae belonging to the Sgr dwarf yield an accurate distance to this galaxy. Their presence also alerts us of the very interesting possibility of distant sources for bulge microlensing events.
منابع مشابه
The RR Lyrae Population of the Galactic Bulge from the MACHO Database : Mean Colors and Magnitudes
Mean colors and magnitudes of RR Lyrae stars in 24 fields towards the Galactic bulge from the MACHO database are presented. Accurate mean reddenings are computed for these fields on the basis of the mean colors. The distribution along the line of sight of the RR Lyrae population is examined on the basis of the mean magnitudes, and it is shown that the bulk of the RR Lyrae population is not barr...
متن کاملar X iv : a st ro - p h / 96 10 02 5 v 1 3 O ct 1 99 6 RR LYRAE STARS IN THE MACHO DATABASE
The MACHO Project has catalogued ∼ 8000 RR Lyrae stars in the Large Magellanic Cloud, ∼ 1800 in the Galactic bulge, and ∼ 50 in the Sgr dwarf galaxy. These variables are excellent distance indicators, and are used as tools to study the structure of the Large Magellanic Cloud and the bulge. The large datasets also probe uncommon pulsation modes. A number of double-mode RR Lyrae stars (RRd) are f...
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