45
© The Author(s), under exclusive license to Springer Nature Switzerland AG 2021
F. Sánchez, The Rise of Astrophysics in Modern Spain, Astronomers’ Universe,
https://doi.org/10.1007/978-3-030-66426-8_6
6
Astronomical Site Testing (1961–1974)
As soon as I got to Izaña in January 1961 I immediately got down to work. I
had managed to find out, roughly, what astronomical site testing was all
about: its purpose was to try to measure atmospheric parameters that would
indicate whether or not a site was suitable for astronomy. Specifically, it was
necessary to make a statistical study of three parameters: cloud cover, sky
transparency, and optical turbulence. The first two are fairly straightforward,
and the third deals with the blurring of images when the atmosphere is
unsteady. The first thing to do was to make an inventory of the instrumentation available on the mountain and see what could be done with it.
I needed only a few days to discover that Teide Observatory consisted of
only two small rooms. One of them was topped with a small dome of wood
and zinc and housed two small (13.0-cm and 11.2-cm) refracting telescopes
on an old equatorial mount. These had been bought from a Catalan amateur
astronomer named Calvet. In spite of my lack of astronomical training, I
quickly saw that the mount was badly aligned with the polar axis, the telescopes badly collimated (to track accurately, the optical axis of the telescope
must be perpendicular to the declination axis of the mount), the tracking
mechanism prone to sudden jerks, the shutter of the camera burnt, a set of
eyepieces missing, and so on. To make matters even more unbearable, the
dome was so badly fitted that, when it snowed, the telescope object glasses
and the dome floor got covered in centimetres of snow, and the power line
suffered a drop of 100 volts. The only bibliography available to me was a useless unpublished report by Professor Redman, the San Fernando Observatory
astronomical ephemeris, and a copy of the elementary Popular Astronomy by
the Galician priest Father Aller.
© The Author(s), under exclusive license to Springer Nature Switzerland AG 2021
F. Sánchez, The Rise of Astrophysics in Modern Spain, Astronomers’ Universe,
https://doi.org/10.1007/978-3-030-66426-8_6
6
Astronomical Site Testing (1961–1974)
As soon as I got to Izaña in January 1961 I immediately got down to work. I
had managed to find out, roughly, what astronomical site testing was all
about: its purpose was to try to measure atmospheric parameters that would
indicate whether or not a site was suitable for astronomy. Specifically, it was
necessary to make a statistical study of three parameters: cloud cover, sky
transparency, and optical turbulence. The first two are fairly straightforward,
and the third deals with the blurring of images when the atmosphere is
unsteady. The first thing to do was to make an inventory of the instrumentation available on the mountain and see what could be done with it.
I needed only a few days to discover that Teide Observatory consisted of
only two small rooms. One of them was topped with a small dome of wood
and zinc and housed two small (13.0-cm and 11.2-cm) refracting telescopes
on an old equatorial mount. These had been bought from a Catalan amateur
astronomer named Calvet. In spite of my lack of astronomical training, I
quickly saw that the mount was badly aligned with the polar axis, the telescopes badly collimated (to track accurately, the optical axis of the telescope
must be perpendicular to the declination axis of the mount), the tracking
mechanism prone to sudden jerks, the shutter of the camera burnt, a set of
eyepieces missing, and so on. To make matters even more unbearable, the
dome was so badly fitted that, when it snowed, the telescope object glasses
and the dome floor got covered in centimetres of snow, and the power line
suffered a drop of 100 volts. The only bibliography available to me was a useless unpublished report by Professor Redman, the San Fernando Observatory
astronomical ephemeris, and a copy of the elementary Popular Astronomy by
the Galician priest Father Aller.