The activity phase of BF Cygni discovered in May 1989 and which lasted about two years is examined. The UV emission lines, usually strong during quiescence...
The activity of comet C/2007 D1 (LINEAR) at 9.7 AU from the Sun
Aims: We report on the unusual distant activity of the dynamically new comet C/2007 D1 (LINEAR), observed at rh = 9.7 AU post-perihelion. This comet is...
The Adequacy of Stellar Evolution Models for the Interpretation of the Color-Magnitude Diagrams of Resolved Stellar Populations
Most of what we know about the stellar population of nearby, resolved galaxies comes from the interpretation of their color-magnitude diagrams, by comparison...
The afterglow and kilonova of the short GRB 160821B
GRB 160821B is a short duration gamma-ray burst (GRB) detected and localized by the Neil Gehrels Swift Observatory in the outskirts of a spiral galaxy at z = 0...
The Afterglows of Swift-era Gamma-ray Bursts. I. Comparing pre-Swift and Swift-era Long/Soft (Type II) GRB Optical Afterglows
We have gathered optical photometry data from the literature on a large sample of Swift-era gamma-ray burst (GRB) afterglows including GRBs up to 2009 September...
The Afterglows of Swift-era Gamma-Ray Bursts. II. Type I GRB versus Type II GRB Optical Afterglows
Gamma-ray bursts (GRBs) have been separated into two classes, originally along the lines of duration and spectral properties, called "short/hard" and "long/soft...
The AG Carinae nebula: abundant evidence for a red supergiant progenitor?
AG Carinae is a massive, evolved supergiant which is thought to be in transition from an O star to a Wolf-Rayet (WR) star and is currently identified as a...
The age decay of stellar magnetic activity in MS field solar-type stars
The age decay of two indicators of the stellar magnetic activity (λ2800 Mg II emission flux and λ10830 He I equivalent width) have been studied for field solar...
The age of extremely red and massive galaxies at very high redshift
Aims: We present a determination of the intrinsic colors and ages of galaxies at very high redshift, in particular old galaxies (OGs) within extremely red...