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Early ⁵⁶Ni decay gamma rays from SN2014J suggest an unusual explosion

Diehl, Roland; Grebenev, Sergei A.; Greiner, Jochen +7 more

Type Ia supernovae result from binary systems that include a carbon-oxygen white dwarf, and these thermonuclear explosions typically produce 0.5 solar mass of radioactive ⁵⁶Ni. The ⁵⁶Ni is commonly believed to be buried deeply in the expanding supernova cloud. In SN2014J, we detected the lines at 158 and 812 kiloelectron volt…

On the prevalence of small-scale twist in the solar chromosphere and transition region

Golub, L.; Tian, H.; De Pontieu, B. +21 more

The solar chromosphere and transition region (TR) form an interface between the Sun’s surface and its hot outer atmosphere. There, most of the nonthermal energy that powers the solar atmosphere is transformed into heat, although the detailed mechanism remains elusive. High-resolution (0.33-arc second) observations with NASA’s Interface Region Imag…

Constraints on Mimas’ interior from Cassini ISS libration measurements

Charnoz, S.; Lainey, V.; Noyelles, B. +4 more

Like our Moon, the majority of the solar system’s satellites are locked in a 1:1 spin-orbit resonance; on average, these satellites show the same face toward the planet at a constant rotation rate equal to the satellite’s orbital rate. In addition to the uniform rotational motion, physical librations (oscillations about an equilibrium) also occur.…

The unresolved fine structure resolved: IRIS observations of the solar transition region

Golub, L.; Tian, H.; De Pontieu, B. +18 more

The heating of the outer solar atmospheric layers, i.e., the transition region and corona, to high temperatures is a long-standing problem in solar (and stellar) physics. Solutions have been hampered by an incomplete understanding of the magnetically controlled structure of these regions. The high spatial and temporal resolution observations with …

The Source Crater of Martian Shergottite Meteorites

Poulet, François; Werner, Stephanie C.; Ody, Anouck

Absolute ages for planetary surfaces are often inferred by crater densities and only indirectly constrained by the ages of meteorites. We show that the <5 million-year-old and 55-km-wide Mojave Crater on Mars is the ejection source for the meteorites classified as shergottites. Shergottites and this crater are linked by their coinciding meteori…

Super-Eddington Mechanical Power of an Accreting Black Hole in M83

Long, K. S.; Soria, R.; Kuntz, K. D. +5 more

Mass accretion onto black holes releases energy in the form of radiation and outflows. Although the radiative flux cannot substantially exceed the Eddington limit, at which the outgoing radiation pressure impedes the inflow of matter, it remains unclear whether the kinetic energy flux is bounded by this same limit. Here, we present the detection o…

Direct observation of closed magnetic flux trapped in the high-latitude magnetosphere

Dandouras, I.; Fazakerley, A. N.; Milan, S. E. +3 more

The structure of Earth’s magnetosphere is poorly understood when the interplanetary magnetic field is northward. Under this condition, uncharacteristically energetic plasma is observed in the magnetotail lobes, which is not expected in the textbook model of the magnetosphere. Using satellite observations, we show that these lobe plasma signatures …

Probing the solar interface region

De Pontieu, Bart; Carlsson, Mats; Title, Alan

Philae probe makes bumpy touchdown on a comet

Hand, Eric

Looking closer at the Sun

Harra, Louise K.