MACHO 176.18833.411

MACHO 176.18833.411
Observation data
Epoch J2000      Equinox J2000
Constellation Sagittarius
Right ascension 18h 00m 13.08s
Declination −27° 15 39.1
Apparent magnitude (V) 17.462
Characteristics
Variable type RR Lyrae
Astrometry
Distance24000±2000 ly
(7300±600 pc)
Details
Metallicity [Fe/H]−1.62 ± 0.2 dex
Other designations
MACHO 176.18833.411, OGLE BLG-RRLYR-10353
Database references
SIMBADdata

MACHO 176.18833.411 (OGLE BLG-RRLYR-10353) is an RR Lyrae variable star located in the galactic bulge of our Milky Way Galaxy. However, it is not a galactic bulge star, it is a galactic halo star, which is on the part of its elliptical orbit that brings it within the bulge before returning to the outer parts of the galaxy, the halo. The star is currently located about 850 pc (2,800 ly) from the Galactic Center. As of 2015, this star has the highest velocity of any known RR Lyrae variable located in the bulge, moving at 482 km/s (1,080,000 mph), only slightly below galactic escape velocity, and 5x the average velocity of bulge stars. Its nature was discovered as part of the BRAVA-RR survey.