Search Publications
Hα emission-line stars in molecular clouds. III. Canis Major
Reipurth, Bo; Pettersson, Bertil
A deep objective-prism survey for Hα emission stars towards the Canis Major star-forming clouds was performed. A total of 398 Hα emitters were detected, 353 of which are new detections. There is a strong concentration of these Hα emitters towards the molecular clouds surrounding the CMa OB1 association, and it is likely that these stars are young …
Long X-ray flares from the central source in RCW 103. XMM-Newton and VLT observations in the aftermath of the 2016 outburst
Tiengo, A.; Rea, N.; Esposito, P. +7 more
We observed the slowly revolving pulsar 1E 161348-5055 (1E 1613, spin period of 6.67 h) in the supernova remnant RCW 103 twice with XMM-Newton and once with the Very Large Telescope (VLT). The VLT observation was performed on 2016 June 30, about a week after the detection of a large outburst from 1E 1613. At the position of 1E 1613, we found a nea…
The high-energy radiation environment of the habitable-zone super-Earth LHS 1140b
Campana, S.; Ghirlanda, G.; Ghisellini, G. +4 more
Context. In the last few years many exoplanets in the habitable zone (HZ) of M-dwarfs have been discovered, but the X-ray/UV activity of cool stars is very different from that of our Sun. The high-energy radiation environment influences the habitability, plays a crucial role for abiogenesis, and impacts the chemistry and evolution of planetary atm…
Colour-dependent accurate modelling of dynamical parallaxes and masses of visual binaries. Application to the VB+SB2 systems with definitive orbits
Andrade, Manuel
Context. Two fundamental characteristics of binary systems are the masses of their components and their distance to the Earth. In this way, the dynamical parallax is an accurate and very helpful tool. Nevertheless, there has been some concern with regard to the use of a unique linear mass-luminosity relation (MLR) for the entire main sequence (MS)…
Observational study of hydrocarbons in the bright photodissociation region of Messier 8
Menten, K. M.; Lee, M. -Y.; Wyrowski, F. +3 more
Aims: Hydrocarbons are ubiquitous in the interstellar medium, but their formation is still not well understood, depending on the physical environment in which they are found. Messier 8 (M8) is host to one of the brightest H II regions and photodissociation regions (PDRs) in our galaxy. With the observed C2H and c-C3H
Exploring the role of X-ray reprocessing and irradiation in the anomalous bright optical outbursts of A0538-66
Mereghetti, S.; Santangelo, A.; Ducci, L. +2 more
Context. In 1981, the Be/X-ray binary A0538-66 showed outbursts characterized by high peak luminosities in the X-ray (Lx ≈ 1039 erg s-1) and optical (Lopt ≈ 3 × 1038 erg s-1) bands. The bright optical outbursts were qualitatively explained as X-ray reprocessing in a gas cloud surrou…
Deep X-ray view of the Class I YSO Elias 29 with XMM-Newton and NuSTAR
Micela, G.; Reale, F.; Sciortino, S. +4 more
X-ray emission is a characteristic feature of young stellar objects (YSOs) and the result of the interplay between rotation, magnetism, and accretion. For this reason high energy phenomena are key elements to understand the process of star formation, the evolution of their circumstellar disks, and eventually the formation of planets. We investigat…
Measuring relative abundances in the solar corona with optimised linear combinations of spectral lines
Buchlin, Éric; Zambrana Prado, Natalia
Context. Elemental abundances in some coronal structures differ significantly from photospheric abundances, with a dependence on the first ionization potential (FIP) of the element. Measuring these FIP-dependent abundance biases is important for coronal and heliospheric physics.
Aims: We aim to build a method for optimal determination of FIP …
Dynamic field line draping at comet 67P/Churyumov-Gerasimenko during the Rosetta dayside excursion
Henri, Pierre; Nilsson, Hans; Behar, Etienne +9 more
Context. The Rosetta dayside excursion took place in September-October 2015 when comet 67P/Churyumov-Gerasimenko (67P/CG) was located at 1.36 AU from the Sun after it had passed perihelion on 13 August 2015 at 1.25 AU. At this time, the comet was near its most active period, and its interaction with the solar wind was expected to be at its most in…
Rosetta/OSIRIS observations of the 67P nucleus during the April 2016 flyby: high-resolution spectrophotometry
Lamy, P. L.; Lara, L. M.; Bertaux, J. -L. +35 more
Context. From August 2014 to September 2016, the Rosetta spacecraft followed comet 67P/Churyumov-Gerasimenko along its orbit. After the comet passed perihelion, Rosetta performed a flyby manoeuvre over the Imhotep-Khepry transition in April 2016. The OSIRIS/Narrow-Angle-Camera (NAC) acquired 112 observations with mainly three broadband filters (ce…