Search Publications
A Study of the Photometric and Spectroscopic Variations of the Prototypical FU Orionis-type Star V1057 Cyg
Cseh, B.; Kriskovics, L.; Pál, A. +19 more
Among the low-mass pre-main sequence stars, a small group called FU Orionis-type objects (FUors) are notable for undergoing powerful accretion outbursts. V1057 Cyg, a classical example of an FUor, went into outburst around 1969-1970, after which it faded rapidly, making it the fastest-fading FUor known. Around 1995, a more rapid increase in fading…
ALMA CO observations of a giant molecular cloud in M 33: Evidence for high-mass star formation triggered by cloud-cloud collisions
Tokuda, Kazuki; Tachihara, Kengo; Sasaki, Manami +14 more
We report the first evidence for high-mass star formation triggered by collisions of molecular clouds in M 33. Using the Atacama Large Millimeter/submillimeter Array, we spatially resolved filamentary structures of giant molecular cloud 37 in M 33 using 12CO(J = 2-1), 13CO(J = 2-1), and C18O(J = 2-1) line emission …
Vortex-like kinematic signal, spirals, and beam smearing effect in the HD 142527 disk
Pinte, C.; Ménard, F.; van der Plas, G. +8 more
Vortices are one of the most promising mechanisms to locally concentrate millimeter dust grains and allow the formation of planetesimals through gravitational collapse. The outer disk around the binary system HD 142527 is known for its large horseshoe structure with azimuthal contrasts of ~3-5 in the gas surface density and of ~50 in the dust. Usi…
A magnetic reconnection model for hot explosions in the cool atmosphere of the Sun
Ni, Lei; Chen, Yajie; Lin, Jun +2 more
Context. Ultraviolet (UV) bursts and Ellerman bombs (EBs) are transient brightenings observed in the low solar atmospheres of emerging flux regions. Magnetic reconnection is believed to be the main mechanism leading to formation of the two activities, which are usually formed far apart from each other. However, observations also led to the discove…
Stellar Superflares Observed Simultaneously with Kepler and XMM-Newton
Kolotkov, Dmitrii Y.; Kuznetsov, Alexey A.
Solar and stellar flares are powerful events that produce intense radiation across the electromagnetic spectrum. Multiwavelength observations are highly important for understanding the nature of flares, because different flare-related processes reveal themselves in different spectral ranges. To study the correlation between thermal and nonthermal …
A tidally tilted sectoral dipole pulsation mode in the eclipsing binary TIC 63328020
Handler, G.; Vanderburg, A.; Saio, H. +13 more
We report the discovery of the third tidally tilted pulsator, TIC 63328020. Observations with the TESS satellite reveal binary eclipses with an orbital period of 1.1057 d, and δ Scuti-type pulsations with a mode frequency of 21.09533 d-1. This pulsation exhibits a septuplet of orbital sidelobes as well as a harmonic quintuplet. Using th…
A new candidate pulsating ULX in NGC 7793
Bachetti, M.; Webb, N. A.; Fürst, F. +2 more
We report here the discovery of NGC 7793 ULX-4, a new transient ultraluminous X-ray source (ULX) in NGC 7793, a spiral galaxy already well known for harbouring several ULXs. This new source underwent an outburst in 2012, when it was detected by XMM-Newton and the Swift X-ray telescope. The outburst reached a peak luminosity of 3.4 × 1039
A search for transiting planets around hot subdwarfs. I. Methods and performance tests on light curves from Kepler, K2, TESS, and CHEOPS
Alonso, R.; Deleuil, M.; Erikson, A. +79 more
Context. Hot subdwarfs experienced strong mass loss on the red giant branch (RGB) and are now hot and small He-burning objects. These stars constitute excellent opportunities for addressing the question of the evolution of exoplanetary systems directly after the RGB phase of evolution.
Aims: In this project we aim to perform a transit survey …
The Pristine Inner Galaxy Survey (PIGS) III: carbon-enhanced metal-poor stars in the bulge
Lewis, Geraint F.; Placco, Vinicius M.; Buder, Sven +15 more
The most metal-deficient stars hold important clues about the early buildup and chemical evolution of the Milky Way, and carbon-enhanced metal-poor (CEMP) stars are of special interest. However, little is known about CEMP stars in the Galactic bulge. In this paper, we use the large spectroscopic sample of metal-poor stars from the Pristine Inner G…
A sub-Neptune and a non-transiting Neptune-mass companion unveiled by ESPRESSO around the bright late-F dwarf HD 5278 (TOI-130)
Bouchy, F.; Rebolo, R.; Pallé, E. +45 more
Context. Transiting sub-Neptune-type planets, with radii approximately between 2 and 4 R⊕, are of particular interest as their study allows us to gain insight into the formation and evolution of a class of planets that are not found in our Solar System.
Aims: We exploit the extreme radial velocity (RV) precision of the ultra-stable…