Category Archives: Instruments

Here we comment on the Different Instruments for the HET

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.

hbias_20211108

HETDEX survey on track towards completion

This week there have been a few press releases from the HET partners about our progress on the HETDEX survey so far. The graphical presentation of the data is amazing and the whole survey will represent a major accomplishment for observational cosmology once completed. Read more at the following links below.

Meanwhile, our hearts are with the radio astronomy community as they mourn the not-unanticipated structural failure of the Arecibo radio telescope this week. Send warm thoughts to all the large aperture telescopes being maintained out there  – they are are precious tools to view the cosmos and is is quite sad to lose such a giant.

 

https://mcdonaldobservatory.org/news/releases/20201201

https://news.psu.edu/story/640405/2020/12/01/research/hobby-eberly-telescope-dark-energy-experiment-survey-begins-full

https://phys.org/news/2020-12-hetdex-track-probe-dark-energy.html

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:

https://hwp-viz.gsd.esrl.noaa.gov/smoke/index.html

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:

https://hpf.psu.edu/2020/09/15/toi-1899/

The PSU press release:

https://science.psu.edu/news/Mahadevan9-2020

And of course the published article itself:

https://arxiv.org/abs/2007.07098

 

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:

https://mcdonaldobservatory.org/news/releases/20200804

For those who want the technical information, see the accepted article on the pre-print server:  https://arxiv.org/abs/2007.12766

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:

https://ui.adsabs.harvard.edu/abs/2020arXiv200509657R/abstract

https://arxiv.org/abs/2005.09657

Eternal spotshine of the spinning red suns