Search Publications
Precise radial velocities of giant stars. XV. Mysterious nearly periodic radial velocity variations in the eccentric binary ε Cygni
Trifonov, Trifon; Reffert, Sabine; Lee, Man Hoi +10 more
Context. Using the Hamilton Échelle Spectrograph at Lick Observatory, we have obtained precise radial velocities (RVs) of a sample of 373 G- and K-giant stars over more than 12 yr, leading to the discovery of several single and multiple planetary systems. The RVs of the long-period (~53 yr) spectroscopic binary ε Cyg (HIP 102488) are found to exhi…
Exploring the pulsational properties of two ZZ Ceti stars
Sódor, Á.; Kalup, Cs.; Bognár, Zs.
Context. We continued our ground-based observing project with the season-long observations of ZZ Ceti stars at the Konkoly Observatory. Our present targets are the newly discovered PM J22299+3024 and the already known LP 119-10 variables. LP 119-10 was also observed by the TESS space telescope in 120-second cadence mode.
Aims: Our main aims a…
Effects of the chromospheric Lyα line profile shape on the determination of the solar wind H I outflow velocity using the Doppler dimming technique
Sasso, C.; Romoli, M.; Andretta, V. +15 more
Context. The determination of solar wind H I outflow velocity is fundamental to shedding light on the mechanisms of wind acceleration occurring in the corona. Moreover, it has implications in various astrophysical contexts, such as in the heliosphere and in cometary and planetary atmospheres.
Aims: We aim to study the effects of the chromosph…
Uncovering the ultimate planet impostor. An eclipsing brown dwarf in a hierarchical triple with two evolved stars
Montesinos, B.; Bouy, H.; Barrado, D. +14 more
Context. Exoplanet searches through space-based photometric time series have shown to be very efficient in recent years. However, follow-up efforts on the detected planet candidates have been demonstrated to be critical to uncover the true nature of the transiting objects.
Aims: In this paper we show a detailed analysis of one of those false …
Extremely weak CO emission in IZw 18
Wang, Junzhi; Zhang, Zhi-Yu; Shi, Yong +1 more
Local metal-poor galaxies are ideal analogues of primordial galaxies with the interstellar medium (ISM) barely being enriched with metals. However, it is unclear whether carbon monoxide remains a good tracer and coolant of molecular gas at low metallicity. Based on the observation with the upgraded Northern Extended Millimeter Array, we report a m…
Observation of bi-directional jets in a prominence
Polito, V.; Hillier, A.
Quiescent prominences host a large range of flows, many driven by buoyancy, which lead to velocity shear. The presence of these shear flows could bend and stretch the magnetic field resulting in the formation of current sheets which can lead to magnetic reconnection. Though this has been hypothesised to occur in prominences, with some observations…
Low surface brightness galaxies in z > 1 galaxy clusters: HST approaching the progenitors of local ultra diffuse galaxies
Muzzin, Adam; Brammer, Gabriel; van der Burg, Remco F. J. +2 more
Ultra diffuse galaxies (UDGs) are a type of large low surface brightness (LSB) galaxies with particularly large effective radii (reff > 1.5 kpc) that are now routinely studied in the Local (z < 0.1) Universe. While they are found to be abundant in clusters, groups, and in the field, their formation mechanisms remain elusive and co…
Photospheric downflows observed with SDO/HMI, HINODE, and an MHD simulation
Malherbe, J. M.; Roudier, T.; Ballot, J. +3 more
Downflows on the solar surface are suspected to play a major role in the dynamics of the convection zone, at least in its outer part. We investigate the existence of the long-lasting downflows whose effects influence the interior of the Sun but also the outer layers. We study the sets of Dopplergrams and magnetograms observed with Solar Dynamics O…
Variable oxygen emission from the accretion disk of Mrk 110
Grosso, N.; Porquet, D.; Reeves, J. N. +2 more
Six XMM-Newton observations of the bright narrow line Seyfert 1, Mrk 110, from 2004-2020, are presented. The analysis of the grating spectra from the Reflection Grating Spectrometer (RGS) reveals a broad component of the He-like Oxygen (O VII) line, with a full width at half maximum of 15 900 ± 1800 km s−1 measured in the mean spectrum.…
A deep XMM-Newton observation of the X-Persei-like binary system CXOU J225355.1+624336
Sidoli, L.; Esposito, P.; La Palombara, N. +2 more
We report on the follow-up XMM-Newton observation of the persistent X-ray pulsar CXOU J225355.1+624336, which was discovered with the CATS@BAR project on archival Chandra data. The source was detected at fX(0.5−10 keV) = 3.4 × 10−12 erg cm−2 s−1, a flux level that is fully consistent with previous observ…