Category Archives: HPF

This is for the HET instrument Habitable-zone Planet Finder

HPF detector maintenance

This past week the HPF instrument team has been working on the detector hardware. Over the past few years the bias/pedestal level has been slowly rising and recent exceeded 40k counts (of a total 65k available to the A/D converter). This high pedestal had begun impacting our ability to observe bright targets without saturation. The graph below shows the gradual rise of this pedestal level since 2019, and the rapid drop achieved this week during the detector maintenance. While the underlying cause of the pedestal rise is unknown, we anticipate that HPF will return to normal science observations in the coming days.


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.