We have identified a new early T dwarf only 3.6 pc from the Sun, as a common proper motion companion (separation 1459 AU) to the K5V star varepsilon Indi (HD...

In the course of a 2.2 micron monitoring programme of nearby Seyfert 1 galaxies, we have detected an outburst in NGC 4051 in which the source flared and dimmed...

We present a polarization variability analysis of a sample of 26 γ-ray blazars monitored by the Steward Observatory between 2008 and 2018 in the optical band...

As part of our ongoing NTT SoFI survey for variability in young free-floating planets and low-mass brown dwarfs, we detect significant variability in the young...

Context. The detection of pulsational frequencies in stellar photometry is required as input for asteroseismological modelling. The second short run (SRa02) of...

Context. The lack of high-precision long-term continuous photometric data for large samples of stars has impeded the large-scale exploration of pulsational...

A total of over 210 hr of previously unpublished differential photoelectric photometry of 21 Com (HD 108945, HR4766), obtained in five years, were analysed to...

Context. After years of modest optical activity, the quasar-type blazar 4C 38.41 (B3 1633+382) experienced a large outburst in 2011, which was detected...

Resonance-scattering polarization and the Hanle effect are powerful but seldom exploited probes into the magnetism of the quiet solar atmosphere. They are also...