Highlights - Volume 480-3 (March IV 2008)

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HIGHLIGHTS: this week in A&A

Volume 480-3 (March IV 2008)


In section 4. Extragalactic astronomy

“Anomalous X-ray emission in GRB060904B: a nickel line?”, by R. Margutti et al., A&A 480, p. 677

This may be the first detection of emission from 56Ni, an element produced in a supernova explosion. X-ray emission from the later X-ray afterglow (from reflection within a small opening angle) apparently yields an abundance of nickel consistent with nucleosynthesis scenarios and ― although a SN was not detected ― are consistent with the reflection of the burst from the environment contaminated (or dominated) by the SN and pre-SN star.  


In section 1. Letters

“q1 Eridani: a solar-type star with a planet and a dust belt”, by R. Liseau et al., A&A 480, p. L47

There is to date only one main sequence star (ε Eridani) associated with having both planets and enough circumstellar dust to be observable at far infrared /submm wavelengths. Liseau and collaborators report in this letter the detection, with the LABOCA instrument on the APEX telescope, of cold dust around the star q1 Eridani, which has an associated Jupiter-mass planet. The authors conclude that there are about 3 Moon masses of mm-sized grains in a belt roughly 300 AU from the star. 
In section 1. Letters

“LMC origin of the hyper-velocity star HE 0437-5439. Beyond the supermassive black hole paradigm”, by N. Przybilla et al., A&A 480, p. L37

Hyper-velocity stars have space velocities that are higher than the escape velocity from the Galaxy. This paper investigates the star HE 0437−543, which moves at a stunning 723 km/s. Based on an analysis of its surface composition, this paper shows that this star is very likely originating in the Large Magellanic Cloud, which implies that a supermassive black hole is not required to explain hyper-velocity stars.  


© Astronomy & Astrophysics 2008