Time-series photometric observations demonstrated the physical origin of this effect. Other stellar classifications As with other RR Lyrae-type variables, RR Lyrae itself has a low abundance of elements other than hydrogen and helium – what astronomers term its metallicity: It belongs to the Population II category of stars that formed during the early period of the Universe when there was a lower abundance of metals in star-forming regions. The trajectory of this star is carrying it along an orbit that is close to the plane of the Milky Way, taking it no more than above or below this plane. The Blazhko period for RR Lyrae is . The orbit has a high eccentricity, bringing RR Lyrae as close as to the Galactic Center at periapsis, and taking it as far as at apapsis. References External links image RR Lyrae 182989 Lyra (constellation) RR Lyrae variables F-type giants Lyrae, RR A-type giants 095497 J19252793+4247040 BD+42 3338 TIC objects