Search Publications
Exocomet orbital distribution around β Pictoris
Heller, René
The ~23 Myr young star β Pictoris (β Pic) is a laboratory for planet formation studies because of its observed debris disk, its directly imaged super-Jovian planets β Pic b and c, and the evidence of extrasolar comets that regularly transit in front of the star. The most recent evidence of exocometary transits around β Pic came from stellar photom…
A benchmark rapidly oscillating chemically peculiar (roAp) star: α Cir
Kallinger, T.; Stassun, K. G.; Kuschnig, R. +1 more
Context. The brightest chemically peculiar magnetic (mCP) star, α Cir, is also pulsating. Precise photometric and spectroscopic data, preferably with a long time base, are needed to investigate its evolutionary aspects as well. The present investigation of α Cir offers a space-based high-precision photometry study with high time resolution, coveri…
A 100 kpc ram pressure tail trailing the group galaxy NGC 2276
Botteon, A.; van Weeren, R. J.; Ignesti, A. +5 more
We present the discovery of a 100 kpc low-frequency radio tail behind the nearby group galaxy, NGC 2276. The extent of this tail is a factor of ten larger than previously reported from higher-frequency radio and X-ray imaging. The radio morphology of the galaxy disc and tail suggest that the tail was produced via ram-pressure stripping, cementing …
Water vapour masers in long-period variable stars. III. Mira variables U Her and RR Aql
Engels, D.; Winnberg, A.; Brand, J.
Context. Water maser emission is often found in the circumstellar envelopes of evolved stars, that is, asymptotic giant branch stars and red supergiants with oxygen-rich chemistry. The H2O emission shows strong variability in evolved stars of both of these types.
Aims: We wish to understand the reasons for the strong variability of…
Polarization of active galactic nuclei with significant VLBI-Gaia displacements
Blinov, Dmitry; Arshinova, Arina
Context. Numerous studies have reported significant displacements in the coordinates of active galactic nuclei (AGNs) between measurements using the very-long-baseline-interferometry (VLBI) technique and those obtained by the Gaia space observatory. There is consensus that these discrepancies do indeed manifest astrometrically resolved sub-compone…
Rotational velocities of blue straggler stars in the globular cluster M 55
Monaco, L.; Mucciarelli, A.; Ferraro, F. R. +3 more
By using high-resolution spectra acquired with FLAMES-GIRAFFE at the ESO/VLT, we measured the radial and rotational velocities of 115 stars in the Galactic globular cluster M 55. After field decontamination based on the radial velocity values, the final sample of member stars is composed of 32 blue straggler stars (BSSs) and 76 reference stars pop…
Asteroid material classification based on multi-parameter constraints using artificial intelligence
Li, Juan; Jiang, Xiaojun; Zhang, Xiaoming +7 more
Context. Material types of asteroids provide key clues to their evolutionary history and contained resources. The Gaia mission has released extensive low-resolution spectral observation data of small Solar System bodies. However, methods for classifying asteroids based on low-resolution space-based spectra are still inadequate, and do not fully le…
A multi-wavelength overview of the giant spiral UGC 2885
Holwerda, Benne; Barmby, Pauline; Gorski, Mark +4 more
Context. UGC 2885 (z = 0.01935) is one of the largest and most massive galaxies in the local Universe, yet it has an undisturbed spiral structure, which is unexpected for such an object and is not predicted by cosmological simulations. Understanding the detailed properties of extreme systems such as UGC 2885 can provide insight into the limits of …
The evolutionary state of the red giant star L2 Puppis
Uttenthaler, S.
Context. L2 Puppis (L2 Pup) is a nearby red giant star and an important object in late-type star research because it has a dust disc and potentially a companion. Aims. L2 Pup is often called the second-closest asymptotic giant branch (AGB) star to the sun, second only to R Doradus. However, whether the star is inde…
A search for Galactic post-asymptotic giant branch stars in Gaia DR3
Dafonte, C.; González-Santamaría, I.; Manteiga, M. +3 more
Context. When low- and intermediate-mass stars leave the asymptotic giant branch (AGB) phase, and before they reach the planetary nebula stage, they enter a very brief and rather puzzling stellar evolutionary stage called post-AGB stage. The post-AGB phase lasts very briefly, about a few thousand years at most. The number of objects that are confi…