In 2012, the size of 2001 QF298 was estimated based on thermal radiation data obtained with the Herschel Space Telescope. The result was 408.2+40.2 −44.9 km.
In the visible light, the object appears to have a neutral or slightly red color.
Dwarf planet candidate
When first discovered, 2001 QF298 was calculated to have an absolute magnitude (H) of 4.7. Light-curve-amplitude analysis from 2008 showed only small deviations, which suggested that 2001 QF298 could be a spheroid about 480 kilometres (300 mi) in diameter with small albedo spots and hence a dwarf planet. It is not included in the same authors' list of dwarf-planet candidates from 2010 because, having an absolute magnitude of 5.4 and assumed albedo of 0.1, it would be less than the cut-off size of 450 kilometres (280 mi) (the same criteria as in the first paper).
^ abcdefgMommert, Michael; Harris, A. W.; Kiss, C.; Pál, A.; Santos-Sanz, P.; Stansberry, J.; Delsanti, A.; Vilenius, E.; Müller, T. G.; Peixinho, N.; Lellouch, E.; Szalai, N.; Henry, F.; Duffard, R.; Fornasier, S.; Hartogh, P.; Mueller, M.; Ortiz, J. L.; Protopapa, S.; Rengel, M.; Thirouin, A. (May 2012). "TNOs are cool: A survey of the trans-Neptunian region—V. Physical characterization of 18 Plutinos using Herschel-PACS observations". Astronomy & Astrophysics. 541: A93. arXiv:1202.3657. Bibcode:2012A&A...541A..93M. doi:10.1051/0004-6361/201118562.
^Doressoundiram, A.; Peixinho, N.; Moullet, A.; Fornasier, S.; Barucci, M. A.; Beuzit, J. -L.; Veillet, C. (2007). "The Meudon Multicolor Survey (2MS) of Centaurs and Trans-Neptunian Objects: From Visible to Infrared Colors". The Astronomical Journal. 134 (6): 2186. Bibcode:2007AJ....134.2186D. doi:10.1086/522783.