Light echoes reveal an unexpectedly cool η Carinae during its nineteenth-century Great Eruption η Carinae is one of the most massive binary stars in the Milky Way. It became the second-brightest star in our sky during its mid-nineteenth-century ‘Great Eruption’, but then faded from view (with only naked-eye estimates of brightness). Its eruption is unique in that it exceeded the Eddington luminosity limit for ten years.Nature 482, 375–378 (16 February 2012), doi:10.1038/nature10775
Astrophysics datamining in the classroom: Exploring real data with new software tools and robotic telescopes Within the efforts to bring frontline interactive astrophysics and astronomy to the classroom, the Hands on Universe (HOU) developed a set of exercises and platform using real data obtained by some of the most advanced ground and space observatories. The backbone of this endeavour is a new free software Web tool - Such a Lovely Software for Astronomy based on Image J (Salsa J). It is student-friendly and developed specifically for the HOU project and targets middle and high schools.
Discovery of Main-Belt Comet P/2006 VW139 by Pan-STARRS1 Main belt asteroid (300163) 2006 VW139 (later designated P/2006 VW139 ) was discovered to exhibit comet-like activity by the Pan-STARRS1 survey telescope using automated point-spread-function analyses performed by PS1’s Moving Object Processing System. Deep follow-up observations show both a short (∼10" ) antisolar dust tail and a longer (∼60" ) dust trail aligned with the object’s orbit plane, similar to the morphology observed for another main-belt comet, P/2010 R2 (La Sagra), and other well-established comets, implying the action of a long-lived, sublimation-driven emission event.Accepted for publication in ApJ Letters
Supernova SN 2011fe from an exploding carbon–oxygen white dwarf star Type Ia supernovae (SNe Ia) have been used empirically as standardized candles to reveal the accelerating universe even though fundamental details, such as the nature of the progenitor system and how the star explodes, remained a mystery. There is consensus that a white dwarf star explodes after accreting matter in a binary system, but the secondary could be anything from a main sequence star to a red giant, or even another white dwarf. The uncertainty stems from the fact that no recent SN Ia has been discovered close enough to detect the stars before explosion.Nature, 480, 344-347 (2011)
Three New Eclipsing White-dwarf - M-dwarf Binaries Discovered in a Search for Transiting Planets Around M-dwarfs We present three new eclipsing white-dwarf / M-dwarf binary systems discovered during a search for transiting planets around M-dwarfs. Unlike most known eclipsing systems of this type, the optical and infrared emission is dominated by the M-dwarf components, and the systems have optical colors and discovery light curves consistent with being Jupiter-radius transiting planets around early M-dwarfs. We detail the PTF/M-dwarf transiting planet survey, part of the Palomar Transient Factory (PTF).
Kepler-22b: A 2.4 Earth-radius Planet in the Habitable Zone of a Sun-like Star A search of the time-series photometry from NASA's Kepler spacecraft reveals a transiting planet candidate orbiting the 11th magnitude G5 dwarf KIC 10593626 with a period of 290 days. The characteristics of the host star are well constrained by high-resolution spectroscopy combined with an asteroseismic analysis of the Kepler photometry, leading to an estimated mass and radius of 0.970 +/- 0.060 MSun and 0.979 +/- 0.020 RSun. The depth of 492 +/- 10ppm for the three observed transits yields a radius of 2.38 +/- 0.13 REarth for the planet.Borucki et al. 2011, ApJ, in press (arXiv:1112.1640)
Dust in Historical Galactic Type Ia Supernova Remnants with Herschel The origin of interstellar dust in galaxies is poorly understood, particularly the relative contributions from supernovae and the cool stellar winds of low-intermediate mass stars. Here, we present Herschel PACS and SPIRE photometry at 70-500m of the historical young supernova remnants: Kepler and Tycho; both thought to be the remnants of Type Ia explosion events.Accepted by MNRAS
Planck early results: First assessment of the Low Frequency Instrument in-flight performance The scientific performance of the Planck Low Frequency Instrument (LFI) after one year of in-orbit operation is presented. We describe the main optical parameters and discuss photometric calibration, white noise sensitivity, and noise properties. A preliminary evaluation of the impact of the main systematic effects is presented. For each of the performance parameters, we outline the methods used to obtain them from the flight data and provide a comparison with pre-launch ground assessments, which are essentially confirmed in flight. Accepted by A&A.
Planck Early Results: The Planck mission The European Space Agency's Planck satellite was launched on 14 May 2009, and has been surveying the sky stably and continuously since 13 August 2009. Its performance is well in line with expectations, and it will continue to gather scientific data until the end of its cryogenic lifetime. We give an overview of the history of Planck in its first year of operations, and describe some of the key performance aspects of the satellite.Accepted by Astronomy & Astrophysics on 31 May 2011
