Theradiation emitted by GR Andromedae is a typical stellarblackbody withabsorption lines from various elements, which gives to the star aspectral type A2pSrCrEu, meaning that unusually strong lines ofstrontium,chromium andeuropium can be observed.[3] GR Andromedae is thus classified as anAp star. The intensity and profile of the spectral lines varies within a cycle with the same period as the brightness variations.[8]
Photometric and spectral variability of GR Andromedae is typical of a star with a strong and variablemagnetic field. This way, the 518.2 days periodicity can be identified as the rotation period of the star.[8] It's among the slowest rotators in the category of magnetic chemically peculiar stars, with a calculatedequatorial rotation rate of only0.2 km/s.[1]
^abcdeGR And, database entry, Combined General Catalog of Variable Stars (GCVS4.2, 2004 Ed.), N. N. Samus, O. V. Durlevich, et al.,CDS IDII/250 Accessed on line 2018-10-17.
^abcCutri, Roc M.; Skrutskie, Michael F.; Van Dyk, Schuyler D.; Beichman, Charles A.; Carpenter, John M.; Chester, Thomas; Cambresy, Laurent; Evans, Tracey E.; Fowler, John W.; Gizis, John E.; Howard, Elizabeth V.; Huchra, John P.; Jarrett, Thomas H.; Kopan, Eugene L.; Kirkpatrick, J. Davy; Light, Robert M.; Marsh, Kenneth A.; McCallon, Howard L.; Schneider, Stephen E.; Stiening, Rae; Sykes, Matthew J.; Weinberg, Martin D.; Wheaton, William A.; Wheelock, Sherry L.; Zacarias, N. (2003)."VizieR Online Data Catalog: 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)".CDS/ADC Collection of Electronic Catalogues.2246: II/246.Bibcode:2003yCat.2246....0C.
^abcdCatalano, F. A.; Leone, F. (June 1990). "Photoelectric photometry of chemically peculiar stars at the Catania astrophysical observatory. Observatory of HD 2453, HD 71866, HD 72968 and HD 126515".Astronomy and Astrophysics Supplement Series.83: 491.Bibcode:1990A&AS...83..491C.
