Related papers: Identifying quiescent compact objects in massive G…
We report on a data-driven spectral model that we have developed for the identification of double-lined spectroscopic binary stars (SB2s) in the LAMOST low-resolution survey (R$\sim$1800). Employing simultaneous fitting with both…
The recently claimed discovery of a massive ($M_\mathrm{BH}=68^{+11}_{-13}\,M_\odot$) black hole in the Galactic solar neighborhood has led to controversial discussions because it severely challenges our current view of stellar evolution. A…
We present the main-sequence binary (MSMS) Catalog derived from Gaia Data Release 3 BP/RP (XP) spectra. Leveraging the vast sample of low-resolution Gaia XP spectra, we develop a forward modeling approach that maps stellar mass and…
Transition disks have large central cavities that have been spatially resolved during recent years. Cavities and other substructures in circumstellar disks are often interpreted as signposts to massive companions. We aim to search for…
The stellar mass-luminosity relation is poorly constrained by observations for high mass stars. We describe our program to find eclipsing massive binaries in the Magellanic Clouds using photometry of regions rich in massive stars, and our…
We present the results of a deep imaging survey of stars surrounded by planets detected with the radial velocity technique. The purpose is to search for and to characterize long-period stellar and substellar companions. The sample contains…
The masses of compact objects like white dwarfs, neutron stars and black holes are fundamental to astrophysics, but very difficult to measure. We present the results of an analysis of subluminous B (sdB) stars in close binary systems with…
Context. This work is part of a long-term spectroscopic study of a sample of 30 multiple stars with early-type components. In this second paper we present the results of six multiple systems in which new stellar components have been…
Recent studies of massive binaries with putative black hole companions have uncovered a phase of binary evolution that has not been observed before, featuring a bloated stripped star that very recently ceased transferring mass to a…
Using Non-Redundant Mask interferometry (NRM), we searched for binary companions to objects previously classified as Transitional Disks (TD). These objects are thought to be an evolutionary stage between an optically thick disk and…
Almost all massive stars are part of a binary system. Given the wide range of separations at which these companions are found, several observational techniques have been adopted to characterize them, but contrasts greater than 4 in the…
We discuss a possible method for detection of dark companions of galactic objects of stellar mass. Such binary systems are likely to occur in the galactic disk and possibly also in the halo. The high incidence of binary and…
The project Massive Unseen Companions to Hot Faint Underluminous Stars from SDSS (MUCHFUSS) aims at finding hot subdwarf stars with massive compact companions (massive white dwarfs M>1.0 Msun, neutron stars or stellar mass black holes). The…
We discuss prospects of identifying and characterizing black hole (BH) companions to normal stars on tight but detached orbits, using photometric data from the Transiting Exoplanet Survey Satellite (TESS). We focus on the following two…
The project Massive Unseen Companions to Hot Faint Underluminous Stars from SDSS (MUCHFUSS) aims at finding hot subdwarf stars with massive compact companions (white dwarfs with masses $M>1.0 {\rm M_{\odot}}$, neutron stars or black holes).…
Hot subdwarf B (sdB) stars are post-main-sequence stars of high temperature and gravity. Approximately 30$\%$ of sdBs exhibit stable pressure and/or gravity-mode pulsations, which can be used via the timing method to test for companion…
The vast majority of extrasolar planets are detected by indirect detection methods such as transit monitoring and radial velocity measurements. While these methods are very successful in detecting short-periodic planets, they are mostly…
The project Massive Unseen Companions to Hot Faint Underluminous Stars from SDSS (MUCHFUSS) aims at finding hot subdwarf stars (sdBs) with massive compact companions such as white dwarfs, neutron stars, or stellar-mass black holes. In a…
We study the Galactic field population of double compact objects (NS-NS, BH-NS, BH-BH binaries) to investigate the number (if any) of these systems that can potentially be detected with LISA at low gravitational-wave frequencies. We…
We have carried out a search for co-moving stellar and substellar companions around 18 exoplanet host stars with the infrared camera MAGIC at the 2.2m Calar Alto telescope, by comparing our images with images from the all sky surveys 2MASS,…