Related papers: The Rosette Eye: the key transition phase in the b…
The canonical picture of star formation involves disk-mediated accretion, with Keplerian accretion disks and associated bipolar jets primarily observed in nearby, low-mass young stellar objects (YSOs). Recently, rotating gaseous structures…
We study numerically the evolution of rotating cloud cores, from the collapse of a magnetically supercritical core to the formation of a protostar and the development of a protostellar disk during the main accretion phase. We find that the…
By comparing photon diffusion time with gas outflow time, I argue that a large fraction of the energy carried by the jets during the grazing envelope evolution (GEE) might end in radiation, hence leading to an intermediate luminosity…
Binary mass transfer via Roche-lobe overflow (RLOF) is a key channel for producing stripped-envelope Wolf-Rayet (WR) stars and may be critical to account for SN Ib/c progenitors. RY Scuti is an extremely rare example of a massive binary…
Massive stars play a dominant role in the process of clustered star formation, with their feedback into the molecular cloud through ionizing radiation, stellar winds and outflows. The formation process of massive stars is poorly constrained…
Rotation plays a key role in the star-formation process, from pre-stellar cores to pre-main-sequence (PMS) objects. Understanding the formation of massive stars requires taking into account the accretion of angular momentum during their PMS…
We discuss the physics and the evolution of a typical massive star passing through an evolutionary stage similar to that of Betelgeuse. After a brief introduction recalling various observed parameters of Betelgeuse, we discuss the…
Wolf-Rayet stars have been detected in a large number of galaxies experiencing intense bursts of star formation. All stars initially more massive than a certain, metallicity-dependent, value are believed to experience the Wolf-Rayet phase…
Stars are unique bodies of the Universe where self-gravity compress matter to such high temperature and density that several nuclear fusion reactions ignite, providing enough feedback against further compression for a time that can be even…
We present Chandra X-ray images of the NGC 2237 young star cluster on the periphery of the Rosette Nebula. We detect 168 X-ray sources, 80% of which have counterparts in USNO, 2MASS, and deep FLAMINGOS images. These constitute the first…
A robust stellar initial mass function (IMF) is crucial in any studies related to star formation. However, the direct measurement of the stellar IMF is confined to the local universe, limited by the resolving power of telescopes. Recently,…
Type IIb supernovae are believed to originate from core-collapse progenitors having kept only a very thin hydrogen envelope. We aim to explore how some physical factors, such as rotation, metallicity, overshooting, and the initial orbital…
The observable characteristics and subsequent evolution of young stellar populations is dominated by their massive stars. As our understanding of those massive stars and the factors affecting their evolution improves, so our interpretation…
The problem of the late accretion phase of the evolution of an axisymmetric, isothermal magnetic disk surrounding a forming star has been formulated in a companion paper. The "central sink approximation" is used to circumvent the problem of…
In this work the most spectacular phenomena occurring during the formation of a star are briefly reviewed: accretion through a rotating disc of matter and outflow through the poles of the new stellar object. Magnetic fields have been…
The detection of interstellar bodies passing near the Sun offers the opportunity to observe not just objects similar to those in the solar system, but also unfamiliar objects without solar system analogues. Here I show that Asymptotic Giant…
Young stars accrete mass from a circumstellar disk, but at the same time disk and star eject outflows and jets. These outflows have an onion-like structure where the innermost and fastest layers are surrounded by increasingly lower velocity…
Circumstellar disks are an essential ingredient of the formation of low-mass stars. It is unclear, however, whether the accretion-disk paradigm can also account for the formation of stars more massive than about 10 solar masses, in which…
The first stars in the universe ionized the ambient primordial gas through various feedback processes. "Second-generation" primordial stars potentially form from this disturbed gas after its recombination. In this Letter, we study the late…
At the earliest evolutionary stages, massive star-forming regions are deeply embedded within their natal cores and not observable at optical and near-infrared wavelengths. Interferometric high-spatial resolution mm dust continuum…