Blader door items (39 in totaal)

Featuring detailed commented spectral profiles of more than one hundred astronomical objects, in colour, this spectral guide documents most of the important and spectroscopically observable objects accessible using typical amateur equipment. It…

There are currently thousands of amateur astronomers around the world engaged in astrophotography at a sophisticated level. Their ranks far outnumber professional astronomers doing the same and their contributions both technically and artistically…

Spectroscopy - once the sole province of professionals - is becoming more and more popular with amateur astronomers. Various instruments, at prices to suit everyone, are already available "off the shelf". "Practical Amateur Spectroscopy" contains…

The Story of the atomic time: Until the 1950s timekeeping was based on the apparent motion of the Sun that in turn reflected the rotation of the Earth on its axis. But the Earth does not turn smoothly. By the 1940s it was clear that the length of the…