Category Archives: Instruments

Here we comment on the Different Instruments for the HET

New results from HPF: planets vs starspots!

The HPF team recently had another publication accepted describing the amazing complexities involved in separating star spots from planets. Their herculean efforts are described on this blog post and in their publication, both linked below:

Eternal spotshine of the spinning red suns

70 VIRUS units on sky

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!


Exciting new results from HPF

HPF’s first new astronomy result is now published!  The team has validated their first planet, G 9-40b.

The article in the Astronomical Journal is available here:

And here is a freely-available version of the paper on the arXiv pre-print server:

Press releases on this from PSU, UT are at:

For a more publicly-accessible description, see the HPF team’s blog:

VIRUS at 59

VIRUS recently celebrated the installation of its 59th unit. Below is a representation of the sky area covered by the current IFUs:


(Note: the VIRUS units (grey squares) do not actually touch each other, but are shown doubled in size to fill in the gaps between them, graphically.)

52 VIRUS units and counting

VIRUS units continue to multiply!  Shown below is a representation of 52 units on the sky:

VIRUS array, expanded images

The grey squares with stars on them are looking at the sky (with more than 23,000 fiberoptic cables taking simultaneous spectra!), and the white squares are empty slots for future units.

The VIRUS units (grey squares) do not actually touch each other, but are shown doubled in size to fill in the gaps between them, graphically.

VIRUS reaches 50+

Much like it is for the blogger, it is a real milestone for VIRUS to hit 50.    In the case of VIRUS it is 50 units.   This was achieved over this past weekend after spending several months with just 47 units.

Reconstruction from 50 IFU/VIRUS units on the sky.  Each small square is 50 arcseconds on a side.   There is actually a gap of 50 arcseconds between each IFU/VIRUS unit but it has been compacted in this view to avoid to much white space.

This means with every 6 minute exposure we take on the sky we get over 22,000 spectra!

On Monday we installed 2 more units bringing us to 52!!!   Well on our way toward HETDEX science!


The week of July 23, 2018

This week at the HET we have taken the top end of the telescope so that we can rework the layout of the IFU fibers and add 11 new fibers.       That will leave just 17 IFU fibers to be installed.   Just to be clear this is not spectrographs being installed but just the IFU fibers that feed future spectrographs.   At the moment we have 41 spectrographs units installed and stable.     This means we are not more than half way towards our total goal of ~78 units.