~0:30-3:30 dip in the brightness of Haumea+Namaka comes when Namaka crosses Haumea (Hi'iaka, the outer moon, is blended in the images, but it rotates every 4.5 hr and adds a little variation)
Mike "plutokiller" Brown will be tweeting about live telescope imaging of the dwarf planet Haumea, and possible transits, at 17:00 UT, 16th June, 2011.
Open notebook science, in which scientists post their data publicly as fast as they collect it, is taking a fresh turn with the release of results in real time via Twitter. On 11 June, astronomer Mike Brown of the California Institute of Technology in Pasadena sparked huge interest by live-tweeting his observations of a transit of dwarf planet Haumea by its moon, Namaka. Read more
By pure coincidence, for next few years the orbit of the satellite Namaka around the dwarf planet Haumea is nearly edge-on to our line-of-sight. This type of configuration does not last for long, because as Haumea travels around the sun in its 283 year orbit, we will continuously see the Haumean system from different angles. It is only edge-on at the angle we see right now, and at the angle it will again be in 141 years -- half of a Haumean year from now. In addition to being an interesting coincidence, the fact that the orbit of Namaka is nearly edge-on provides the opportunity for gaining an enormous amount of information about the Haumean system. Over the course of Namaka's 19-day orbit around Haumea, Namaka will pass in front of and behind Haumea, temporarily disappearing. While the Haumean system is so far away that we will never be able to directly watch these disappearances, we will be able to notice that when Namaka disappears behind Haumea, for example, the total amount of light from the system will go down by a small amount. When Haumea reappears the total amount of light will go back up. Read more
Title: High-contrast observations of 136108 Haumea. A crystalline water-ice multiple system Authors: Christophe Dumas, Benoit Carry, Daniel Hestroffer, Frederic Merlin
Context. The trans-neptunian region of the Solar System is populated by a large variety of icy bodies showing great diversity in orbital behaviour, size, surface colour and composition. One can also note the presence of dynamical families and binary systems. One surprising feature detected in the spectra of some of the largest Trans-Neptunians is the presence of crystalline water-ice. This is the case for the large TNO (136 108) Haumea (2003 EL61). Aims. We seek to constrain the state of the water ice of Haumea and its satellites, and investigate possible energy sources to maintain the water ice in its crystalline form. Methods. Spectro-imaging observations in the near infrared have been performed with the integral field spectrograph SINFONI mounted on UT4 at the ESO Very Large Telescope. The spectra of both Haumea and its larger satellite Hi'iaka are analysed. Relative astrometry of the components is also performed, providing a check of the orbital solutions and equinox seasons. Results. We describe the physical characteristics of the crystalline water-ice present on the surface of Haumea and its largest satellite Hi'iaka and analyse possible sources of heating to maintain water in crystalline state: tidal dissipation in the system components vs radiogenic source. The surface of Hi'iaka appears to be covered by large grains of water ice, almost entirely in its crystalline form. Under some restricted conditions, both radiogenic heating and tidal forces between Haumea and Hi'iaka could provide the energy sufficient to maintain the ice in its crystalline state. Based on observations collected at the European SouthernObservatory, Paranal, Chile - 60.A-9235
El planeta enano Haumea brilla con hielo cristalino
El quinto planeta enano del sistema solar, Haumea, y al menos uno de sus dos satélites, mantienen agua helada cristalina gracias a las fuerzas mareales entre ellos y al calor de elementos radiactivos. Así lo refleja un estudio internacional, con participación española, realizado con las observaciones del telescopio VLT del Observatorio Europeo Austral en Chile. Read more (Spanish)
Haumea and Namaka are currently undergoing a series of mutual occultations and eclipses.
By pure coincidence, for next few years the orbit of the satellite Namaka around the dwarf planet Haumea is nearly edge-on to our line-of-sight. This type of configuration does not last for long, because as Haumea travels around the sun in its 283 year orbit, we will continuously see the Haumean system from different angles. It is only edge-on at the angle we see right now, and at the angle it will again be in 141 years -- half of a Haumean year from now. Read more
Title: "TNOs are cool": A survey of the trans-neptunian region. II. The thermal lightcurve of (136108) Haumea Authors: E. Lellouch, C. Kiss, P. Santos-Sanz, T.G. Müller, S. Fornasier, O. Groussin, P. Lacerda, J.L. Ortiz, A. Thirouin, A. Delsanti, R. Duffard, A.W. Harris, F. Henry, T. Lim, R. Moreno, M. Mommert, M. Mueller, S. Protopapa, J. Stansberry, D. Trilling, E. Vilenius, A. Barucci, J. Crovisier, A. Doressoundiram, E. Dotto, P.J. Gutiérrez, O. Hainaut, P. Hartogh, D. Hestroffer, J. Horner, L. Jorda, M. Kidger, L. Lara, M. Rengel, B. Swinyard, N. Thomas
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.