STATUS REPORT: SEPTEMBER 9, 2013
The Hobby-Eberly Telescope went dark in late August — the first step toward an upgrade that will allow it to probe the nature of dark energy.
Earlier, both an independent review panel and the HETDEX board of directors had confirmed that the project was ready to begin the months-long upgrade, which will greatly improve the telescope’s scientific capabilities.
“This is an exciting step for everybody,” says HETDEX principal investigator Gary Hill. “We knew we were ready to go, and it was great to get the okay to go ahead.”
HET staff members began removing half of the telescope’s 91 hexagonal mirrors on August 12, with the last scientific observations on August 28. The mirrors will be recoated and stored to keep them safe while new equipment is installed on the telescope.
The staff then removed the Prime Focus Instrument Package (PFIP) at the top of the telescope. PFIP provided a set of mirrors that brought starlight to a sharp focus, guidance cameras, and the Low Resolution Spectrograph, which split the light from astronomical objects into its individual wavelengths or colors. “That instrument won’t be redeployed on the telescope — it’s had its life,” says Hill, who build the instrument 15 years ago. It will be replaced by an improved model.
Final testing and verification of the new Wide-Field Corrector, which will allow the telescope to see a much larger patch of sky with each observation, is underway, and should be completed this fall, Hill says. The corrector is one of the key elements of the new PFIP, which will be installed next year.
Over the coming months, staff members will remove the tracker at the top of the telescope, which allowed HET to follow astronomical objects as Earth rotated beneath it. A new tracker has been completed by the Center for Electromechanics at The University of Texas at Austin, and it will be dismantled, packed, and shipped to McDonald Observatory for installation.
When the HET upgrades are completed, the VIRUS units will be loaded on the telescope and astronomers will begin verifying the performance of both the instruments and the telescope itself. First light for the upgraded telescope is expected by June of 2014, with full HETDEX science operations beginning a few months later.