The thermal environment of the fiber glass dome for the new solar telescope at Big Bear Solar Observatory

The New Solar Telescope (NST) is a 1.6-meter off-axis Gregory-type telescope with an equatorial mount and an open optical support structure. To mitigate the temperature fluctuations along the exposed optical path, the effects of local/dome-related seeing have to be minimized. To accomplish this, NST will be housed in a 5/8-sphere fiberglass dome that is outfitted with 14 active vents evenly spaced around its perimeter. The 14 vents house louvers that open and close independently of one another to regulate and direct the passage of air through the dome. In January 2006, 16 thermal probes were installed throughout the dome and the temperature distribution was measured. The measurements confirmed the existence of a strong thermal gradient on the order of 5° Celsius inside the dome. In December 2006, a second set of temperature measurements were made using different louver configurations. In this study, we present the results of these measurements along with their integration into the thermal control system (ThCS) and the overall telescope control system (TCS).

[1]  Yong-Jae Moon,et al.  Development of a correlation tracker system for the New Solar Telescope , 2008, Astronomical Telescopes + Instrumentation.

[2]  Friedrich Wöger,et al.  KISIP: a software package for speckle interferometry of adaptive optics corrected solar data , 2008, Astronomical Telescopes + Instrumentation.

[3]  Haimin Wang,et al.  Solar activity monitoring and forecasting capabilities at Big Bear Solar Observatory , 2002 .

[4]  P. R. Goode,et al.  Globally Integrated Measurements of the Earth’s Visible Spectral Albedo , 2005, astro-ph/0505084.

[5]  Carsten J. Denker,et al.  Integrating seeing measurements into the operations of solar telescopes , 2006, SPIE Astronomical Telescopes + Instrumentation.

[6]  H. M. Martina,et al.  Manufacture of 8 . 4 m off-axis segments : a 1 / 5 scale demonstration , 2004 .

[7]  W. Timothy Liu,et al.  Oceanic thermal and biological responses to Santa Ana winds , 2003 .

[8]  J. R. Varsik,et al.  Design of a telescope pointing and tracking subsystem for the Big Bear Solar Observatory New Solar Telescope , 2006, SPIE Astronomical Telescopes + Instrumentation.

[9]  O. von der Lühe,et al.  High Resolution Solar Speckle Imaging With the Extended Knox–Thompson Algorithm , 2006 .

[10]  A. P. Verdoni,et al.  The telescope control system of the New Solar Telescope at Big Bear Solar Observatory , 2006, SPIE Astronomical Telescopes + Instrumentation.

[11]  Friedrich Wöger,et al.  Adaptive Optics at the Big Bear Solar Observatory: Instrument Description and First Observations , 2007 .

[12]  C. Denker,et al.  The Local Seeing Environment at Big Bear Solar Observatory , 2007 .

[13]  Jose Teran,et al.  Unique dome design for the SOAR telescope project , 2000, Astronomical Telescopes + Instrumentation.

[14]  Haosheng Lin,et al.  Solar site testing for the Advanced Technology Solar Telescope , 2004, SPIE Astronomical Telescopes + Instrumentation.

[15]  A. P. Verdoni,et al.  Progress on the 1.6-meter New Solar Telescope at Big Bear Solar Observatory , 2006, SPIE Astronomical Telescopes + Instrumentation.

[16]  F. Hill,et al.  The global oscillation network group site survey , 1994 .

[17]  O. von der Lühe,et al.  Speckle imaging of solar small scale structure. I - Methods , 1993 .

[18]  Kevin Reardon,et al.  Speckle interferometry with adaptive optics corrected solar data , 2008 .

[19]  Guo Yang.  Design and implementation of the primary and secondary mirror control system for NST , 2006, SPIE Astronomical Telescopes + Instrumentation.

[20]  PHILIP R. GOODE,et al.  SOLAR TELESCOPE IN BIG BEAR – THE NST , 2003 .

[21]  E. M. Standish,et al.  JPL's On-Line Solar System Data Service , 1996 .

[22]  M. Collados,et al.  Solar Site Survey for the Advanced Technology Solar Telescope. I. Analysis of the Seeing Data , 2005, astro-ph/0508690.