"TNOs are cool": A survey of the trans-neptunian region. II. The thermal lightcurve of (136108) Haumea

Abstract : Thermal emission from Kuiper Belt object (136108) Haumea was measured with Herschel-PACS at 100 and 160 micrometers for almost a full rotation period. Observations clearly indicate a 100-micrometer thermal lightcurve with an amplitude of a factor of ~ 2, which is positively correlated with the optical lightcurve. This confirms that both are primarily due to shape effects. A 160-micrometer lightcurve is marginally detected. Radiometric fits of the mean Herschel- and Spitzer- fluxes indicate an equivalent diameter D ~ 1300 km and a geometric albedo p_v ~ 0.70-0.75. These values agree with inferences from the optical lightcurve, supporting the hydrostatic equilibrium hypothesis. The large amplitude of the 100-micrometer lightcurve suggests that the object has a high projected a/b axis ratio (~ 1.3) and a low thermal inertia as well as possible variable infrared beaming. This may point to fine regolith on the surface, with a lunar-type photometric behavior. The quality of the thermal data is not sufficient to clearly detect the effects of a surface dark spot.
Type de document :
Pré-publication, Document de travail
Accepted for publication in Astronomy & Astrophysics (special issue on Herschel first results). 2010
Liste complète des métadonnées

https://hal.archives-ouvertes.fr/hal-00662137
Contributeur : Catherine Beaussier <>
Soumis le : lundi 23 janvier 2012 - 12:17:42
Dernière modification le : mardi 11 octobre 2016 - 14:59:17

Identifiants

  • HAL Id : hal-00662137, version 1
  • ARXIV : 1006.0095

Citation

E. Lellouch, C. Kiss, P. Santos-Sanz, T. G. Müller, S. Fornasier, et al.. "TNOs are cool": A survey of the trans-neptunian region. II. The thermal lightcurve of (136108) Haumea. Accepted for publication in Astronomy & Astrophysics (special issue on Herschel first results). 2010. <hal-00662137>

Partager

Métriques

Consultations de la notice

150