siderostat Astr.
(ˈsɪdərəʊstæt)
[f. sidero-2, after heliostat.]
An astronomical instrument by which a star under observation may be kept within the same part of the field of a telescope.
| 1877 G. F. Chambers Astron. (ed. 3) Vocab. 916 A form of the instrument [heliostat] specially used for astronomical purposes is called a siderostat. 1878 Lockyer Stargazing 343 One of the most recent additions to astronomical tools is the Siderostat. 1881 Abney Photogr. 289 Before the introduction of Foucault's siderostat a telescope would have had to be mounted equatorially, and a clock motion would probably have been necessary. |
Hence sideroˈstatic a.
| 1879 Proc. Roy. Soc. Dublin II. 361 The Siderostatic Telescope..is principally intended for solar spectroscopic investigation. 1885 A. M. Clerke Hist. Astron. 450 An instrument with ‘siderostatic’ mounting. |