4.85 and 10.45 GHz observations of XTE J1118+480 following the VLA measurements
40 - 350 micron emission from NGC 2023.
40 Eridani and the gravitational lens effect
40 Eridani.
40 Eridani: The Vulcan Sun as a Benchmark for the Evolutionary Properties of White Dwarfs and Cool Stars
40 Jahre Astronomieunterricht in Ostdeutschland.
40 neue Veränderliche
40 Years of Pulsars: The Birth and Evolution of Isolated Radio Pulsars
40 Years of Solar Microwave Burst Flux Measurements
40 years of the astronomical contest for schoolchildren.
40 Years Since Gagarin's Flight to Space. (Slovenian Title: 40-letnica Gagarinovega poleta v vesolje)
40-350 micron observations of galactic sources
400 Mc/s partial eclipse observations on 30 June 1954
400 years of astrometry: from Tycho Brahe to Hipparcos
400 Years of Astronomical Discovery: The Accelerating Understanding of our Place in the Universe
400 Years of Astronomical Telescopes
400 Years of Telescopes. (Slovenian Title: Stiristo let teleskopov)
400 Years of the Telescope
400 years on from Tycho and Kepler.
4000 Globular Clusters in M87