Category Archives: HPF

This is for the HET instrument Habitable-zone Planet Finder

Hazy skies overhead and HPF discovers the first warm Jupiter around an M dwarf

In the past couple weeks we’ve noticed significant (30-60%) reductions in the amount of starlight reaching the telescope, due to the smoke overhead:

It makes the sunsets eerie and washes out the Milky Way at night, too. Hopefully this situation will improve soon! The extinction seems worst at the blue wavelengths (like those that VIRUS uses) and is not bad for redder light (HPF observations are mostly unaffected).



On the brighter side, yet another HPF paper has been accepted and published – this one is the discovery and confirmation of the first transiting ‘warm’ Jupiter around an M dwarf. You can read the HPF team’s blog post about it:

The PSU press release:

And of course the published article itself:


Hot Jupiters are rare around M dwarfs, and transiting warm Jupiters rarer still. The TESS spacecraft only detected a single transit – and it was only with HPF that we could nail down the orbital period and mass. This one definitely highlights the power of the HET and queue! Congrats to the whole team!

A Young Sub-Neptune-sized Planet Sheds Light onto How Planets Form and Evolve

Check out the latest results from the HET! There was a press release about this fascinating discovery:

For those who want the technical information, see the accepted article on the pre-print server:

In short, this is a planet around a M dwarf in the Hyades cluster (so we know age and metallicity very well- both of which are tricky for M dwarfs), and is more massive  than expected- based on mass derived with HPF radial velocities. With multiple observations during transit we also have determined the spin-orbit alignment of this planet with the rotation axis of its star- which points to a well aligned orbit.
Great work to the HPF team, and the HET staff for another (massively) cool exoplanet discovery!

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

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:

The week of July 2nd 2018

It has been a while since I posted and I think one of our biggest pieces of new is that we are now regularly observing with HPF.    Not only is this instrument being used to observe host stars for planets but there are astronomers who are using it to observe planetary nebulae looking for new elements being born in the deaths of stars just slightly heavier than our sun.   This new instrument is easy to use, reliable and a great addition to the HET.

The other big news is that we now have 40 double barreled spectrographs installed within VIRUS.   That means that we are now more than half way to have VIRUS fully populated.



The week of February 26, 2018

This week we continued with HPF and Laser Frequency Comb (LFC) commissioning. We made a lot forward progress in getting spectra with the comb and had our official “first light”. Below are a few pictures that might help visualize some of what transpired.

A slide that shows the basement of the HET where the HPF and LFC live.

A part of the spectrum from HPF which shows the very regular picket fense of emission lines generated from the LFC just below a stellar spectrum. The spectra are stacked up in an echellogram.

A very happy HPF team, NIST team and HET Night Operations team celebrate first spectrum on the sky. It took a large number of people to get this entire effort going but here are the lucky ones to see it live!

The week of February 19, 2018

In the last week we have had a few updates for two of our instruments. For VIRUS we are up to 29 working spectrographs. We actually have several more units but some of the oldest and slightly mis-behaving units have been sent back to Austin for realignment and recommissioning. For HPF we are thrilled to announce that a NIST laser comb has been installed in the calibration room in the HET basement. This allows us to send a picket fence of spectral features through a separate fiber next to the science fibers. During the data reduction and analysis of the HPF spectra they can look at the position of these pickets and determine how the instrument might be subtly moving and correct for it. So far it seems like it is working great.

The week of October 16

The exciting news this week has been the arrival of the Habitable Planet Finder (HPF). This is the first of our new high resolution instruments and an instrument well suited to working in bright moon conditions. The HPF was designed and built by our Penn State partners and arrived on the 16th.

This instrument is designed for extremely high precision spectroscopy capable of detecting the reflex motion of stars as small earth sized planets go around them. To achieve that precision the instrument is housed in our temperature controlled basement at the HET inside a temperature controlled room inside a large temperature controlled vacuum chamber. All of these efforts allow them to control the temperature of the optics of the instrument at a level of 0.001 degrees Celsius.

After very carefully cleaning the enclosure that will house the vacuum chambered instrument the HPF team

was able to open their instrument and after a very through inspection proudly announced that they have just as many pieces of glass as they did in the assembly lab at Penn State (an optics joke). After a few final checks and the inclusion of their single moving part inside of the spectrograph they sealed up the vacuum chamber which, if things continue to go very well, may remain sealed for several years to come. The process of pumping the vacuum out of the large chamber took the rest of the weekend.

In the coming days and weeks the HPF team will monitor its stability, install the laser metrology system and get the systems ready for on-sky commissioning.

Quite an exhausting and exciting week at the HET!