Search Publications
Resonance locking in giant planets indicated by the rapid orbital expansion of Titan
Fuller, Jim; Modenini, Dario; Tortora, Paolo +8 more
Saturn is orbited by dozens of moons, and the intricate dynamics of this complex system provide clues about its formation and evolution. Tidal friction within Saturn causes its moons to migrate outwards, driving them into orbital resonances that pump their eccentricities or inclinations, which in turn leads to tidal heating of the moons. However, …
A kilonova associated with GRB 070809
Li, Xiang; Jin, Zhi-Ping; Covino, Stefano +4 more
For on-axis typical short gamma-ray bursts (sGRBs), the forward shock emission is usually so bright1,2 that it renders the identification of kilonovae (also known as macronovae)3-6 in the early afterglow (t < 0.5 d) phase rather challenging. This is why previously no thermal-like kilonova component has been identified at s…
The carbon monoxide-rich interstellar comet 2I/Borisov
Feldman, P. D.; Bodewits, D.; Noonan, J. W. +7 more
Interstellar comets offer direct samples of volatiles from distant protoplanetary disks. 2I/Borisov is the first notably active interstellar comet discovered in our Solar System1. Comets are condensed samples of the gas, ice and dust that were in a star's protoplanetary disk during the formation of its planets, and inform our understand…
A measurement of water vapour amid a largely quiescent environment on Europa
Villanueva, G. L.; Roth, L.; Paganini, L. +4 more
Previous investigations proved the existence of local density enhancements in Europa's atmosphere, advancing the idea of a possible origination from water plumes. These measurement strategies, however, were sensitive either to total absorption or atomic emissions, which limited the ability to assess the water content. Here we present direct search…
An extremely energetic supernova from a very massive star in a dense medium
Bieryla, Allyson; Laher, Russ R.; Masci, Frank J. +14 more
The interaction of a supernova with a circumstellar medium (CSM) can dramatically increase the emitted luminosity by converting kinetic energy to thermal energy. In `superluminous' supernovae of type IIn—named for narrow hydrogen lines1 in their spectra—the integrated emission can reach2-6 ~1051 erg, attainable by …
AstroSat detection of Lyman continuum emission from a z = 1.42 galaxy
Verhamme, Anne; Inoue, Akio K.; Schaerer, Daniel +10 more
One of the outstanding problems of current observational cosmology is to understand the nature of sources that produced the bulk of the ionizing radiation after the Cosmic Dark Age. Direct detection of these reionization sources1 is practically infeasible at high redshift (z) due to the steep decline of intergalactic medium transmission…
Highlights of exoplanetary science from Spitzer
Deming, Drake; Knutson, Heather A.
Observations of extrasolar planets were not projected to be a substantial part of the Spitzer Space Telescope's mission when it was conceived and designed. Nevertheless, Spitzer was the first facility to detect thermal emission from a hot Jupiter-sized planet, and the range of its exoplanetary investigations grew to encompass transiting planets, m…
A plague of magnetic spots among the hot stars of globular clusters
Gullieuszik, M.; Milone, A. P.; Stetson, P. B. +15 more
For more than six decades, the quest to understand the formation of hot (about 20,000-30,000 K) extreme horizontal branch (EHB) stars in Galactic globular clusters has remained one of the most elusive in stellar evolutionary theory. Here we report on two discoveries that challenge the idea of the stable luminosity of EHB stars. The first mode of E…
A year-long plateau in the late-time near-infrared light curves of type Ia supernovae
Ryan, R.; Maguire, K.; Graur, O. +6 more
The light curves of type Ia supernovae are routinely used to constrain cosmology models. Driven by radioactive decay of 56Ni, the light curves steadily decline over time, but after 150 d post-explosion the near-infrared portion is poorly characterized. We report a year-long plateau in the near-infrared light curve at 150-500 d, followed…
A giant galaxy in the young Universe with a massive ring
Kacprzak, Glenn G.; Glazebrook, Karl; Labbé, Ivo +12 more
In the local (redshift z ≈ 0) Universe, collisional ring galaxies make up only ~0.01% of galaxies1 and are formed by head-on galactic collisions that trigger radially propagating density waves2-4. These striking systems provide key snapshots for dissecting galactic disks and are studied extensively in the local Universe5…