It is very likely a dwarf planet. A diameter of 680±34 km has been calculated from combined observations of the Herschel and Spitzer space telescopes. Light-curve-amplitude analysis shows only small deviations, suggesting that 2004 GV9 could be a spheroid with small albedo spots and hence a dwarf planet.
It has been observed forty-seven times, with precovery images back to 1954.
^ abcE. Vilenius, C. Kiss, M. Mommert, T. M¨uller, P. Santos-Sanz, A. Pal, J. Stansberry, M. Mueller, N. Peixinho, S. Fornasier, E. Lellouch, A. Delsanti, A. Thirouin, J. L. Ortiz, R. Duffard, D. Perna, N. Szalai, S. Protopapa, F. Henry, D. Hestroffer, M. Rengel, E. Dotto, and P. Hartogh (2012). "TNOs are Cool: A survey of the trans-Neptunian region VI. Herschel⋆/PACS observations and thermal modeling of 19 classical Kuiper belt objects". arXiv:1204.0697v1 [astro-ph].