Analysis of thermal conditions of the 6-m BTA telescope elements and the telescope dome space

Abstract

The results obtained using the temperature monitoring systems of the 6-m BTA telescope primary mirror, dome space, and external environment are reported. We consider the factors that affect the development of microturbulence in the near-mirror air layer and inside the dome space, variation of the telescope focal length with the temperature of its structures, variation of seeing due to temperature gradients inside the primary mirror of the 6-m telescope. The methods used in various observatories for reducing microturbulence are analyzed. We formulate suggestions concerning the improvement of the temperature monitoring system currently in operation and the system of automatic adjustment of the telescope focal length to compensate the thermal drift of the focus during observations.

High-precision temperature monitoring system for room-temperature equipment in astrophysical observations

“…Several radio-astronomical experiments have measured the room-temperature area for a telescope foundation or mirror deformation, but the precision was insufficient for reducing the noise of the CMB experiment 1112 . 13 In this paper, we show the requirements for a precise of room-temperature monitoring system and demonstrate that our thermometry system satisfies these requirements. We focus on the mirror and the readout electronics as room-temperature instruments on the basis of the design of the POLARBEAR-2 telescope system in the Simons Array.…”