We report discovery of a bright, nearby () Sun-like star orbiting a dark object. We identified
the system as a black hole candidate via its astrometric orbital solution from the Gaia …

Massive stars play a major role in the evolution of their host galaxies and serve as important
probes of the distant Universe. It has been established that the majority of massive stars …

Stellar-mass black holes are the final remnants of stars born with more than 15 solar
masses. Billions are expected to reside in the Local Group, yet only a few are known, mostly …

We describe the discovery of a solar neighborhood (d= 468 pc) binary system with a main-
sequence sunlike star and a massive noninteracting black hole candidate. The spectral …

Context. The quest to detect dormant stellar-mass black holes (BHs) in massive binaries (ie
OB+ BH systems) is challenging; only a few candidates have been claimed to date, all of …

We present the merger rate density of Population III binary black holes (BHs) by means of a
widely used binary population synthesis code BSE with extensions to very massive and …

Magnetars are highly magnetized neutron stars, the formation mechanism of which is
unknown. Hot helium-rich stars with spectra dominated by emission lines are known as Wolf …

We analyse two binary systems containing giant stars, V723 Mon ('the Unicorn') and
2M04123153+ 6738486 ('the Giraffe'). Both giants orbit more massive but less luminous …

The B emission-line stars are rapid rotators that were probably spun up by mass and
angular momentum accretion through mass transfer in an interacting binary. Mass transfer …

We show that the radial velocity variable star in the black hole (BH) candidate NGC 1850
BH1 cannot be a normal subgiant, as was proposed, but is an overluminous stripped …