This week the VIRUS spectrograph reached another milestone with 70 active units on sky. Below is a reconstructed/magnified image of one observation (the units actually have gaps between them but are shown magnified here). White squares show the locations for 8 remaining units.
Each dithered VIRUS observation now contains 31,000 spectra covering 46 square arcminutes. Next stop: the full 78 units!
After the our Iron-Argon (FeAR) lamp started showing significantly reduced flux, on April 6th our team replaced the bulb in our Facility Calibration Unit (which rides along on the tracker, supplying continuum and line lamps for all the instruments). The new FeAr lamp is back to full brightness and provides excellent narrow emissions lines for our wavelength solutions on the Low Resolution Spectrograph #2.
The old bulb (left) looks quite dark and cloudy compared to the new one (right):