Between dusk and dawn with the northern twin of HARPS

By Zaira M. Berdiñas, Instituto de Astrofísica de Andalucía (IAA-CSIC)

Observatories are the astronomers’ lab, or rather, they are our spy-holes to observe the Universe—the vastest lab of all.

Do you know someone who, when looking up at the sky, says: “Bah!, I don’t like it”? I really don’t, however, living in bright cities doesn’t give us many chances of testing such reactions; and maybe this is also the reason why the huge Universe is not something we use to think about every day. That’s why, when we meet someone and they want to know about our “starry profession”, they ask—with a mixture of curiosity and oddness—“How did you decide to become an astrophysicist?”. How life is in an observatory can cause the same feeling, sometimes I think even my mother doesn’t know what I’m doing up there—don’t be angry mom!—so in this article I’ll describe a bit of the daily routine on the mountain.

Starting the trip in Granada’s airport. Credits: Zaira M. Berdiñas.

As with many other trips, this one starts at the airport. But wait, that’s not fair, because before starting the journey to the observatory a lot of work was already done. Twice a year, telescopes offer their nights through the so-called “call for proposals”. This starts a period in which astronomers have to squeeze their brains and compete for writing the best science projects. Telescope time is expensive, and only those who prove that they will make the best use of it will be awarded with the opportunity of using it. “Time allocation committees” which are also formed by astronomers, decide who pass and who don’t. So, I’m at the airport, and this implies that our science project made the cut (hooray!). After a 3-hour flight I land at the island of La Palma; you may think I’m almost there, but hundreds of curves still separate me from the Observatory of Roque de los Muchachos. Carlos the driver, and after this winding road my friend, leaves me in the Residencia. This is the core of observatory life: here astronomers have late breakfasts and early dinners, sleep in the daytime, and even play ping-pong in their free time. But my watch shows it’s 4 PM and I have no time to lose before dusk. I take a car and I drive up to the Telescope Nazionale Galileo (TNG), where Vania, my support astronomer, is waiting in the telescope control room to explain to me how to set up the instrument I’ll use to collect my data: HARPS-N.

Left: Telescopio Nazionale Galileo (TNG). Right: Control room sited in the ground floor of the telescope building. Screens on the right are used by the telescope operator to monitor the weather and the telescope parameters, screens on the left correspond to HARPS-N. Credits: Zaira M. Berdiñas.

In the same way that Pale Red Dot is using HARPS, settled at ESO’s La Silla Observatory (Chile), to collect the radial velocities of Proxima Centauri, tonight I’ll use HARPS-N, his twin in the northern hemisphere, to search for other planets orbiting other red stars. Once Vania has finished the training and we have initialized and calibrated the instrument response, I’m just in time for coming back to the Residencia, having dinner, picking up my “super-snack” for the night, reading some emails from my team wishing me clear skies, and coming back to the telescope with the dusk right on my tail. On my way up, the open dome tells me that Daniele, the telescope operator, may be ready to start observations. Roughly one hour after twilight, sky is dark enough to start the telescope focus procedure: the night has started.

Telescopio Nazionale Galileo with its dome open in my way up from the Residence. Credits: Zaira M. Berdiñas

I spend the rest of the night observing my targets. That means sending the observation blocks to point the telescope and trigger the exposure, while I make sure that the spectra I’m collecting are good. Daniele, who is by my side, monitors the weather conditions and telescope parameters from almost 9 screens. It’s almost 2 AM and it’s the turn of the faintest star on my list. It requires a longer exposure and gives me the opportunity to go outside and enjoy one of the most astonishing skies that you can stare at and, why not, take some pics.

Photograph of the Milky Way  and the Telescope Nazionale Galileo taken whilst a long exposure is being acquired. Credits: Zaira M. Berdiñas.

After almost 10 hours and more than one coffee, the new day dawns. After having closed all the systems, we drive all the way down to the Residencia, always with no lights to avoid bothering our colleagues in case they were still doing some final tests. And we are done, data will be analysed over the next few months but now it’s 7 AM and the night is officially over, the only thing awaiting for me is my bed. Good day!

Zaira M. Berdiñas

About the author.

Zaira M. Berdiñas is a last year PhD student, working in the CARMENES spectrograph group at the Instituto de Astrofísica de Andalucía. Her research is mainly focused on searching for compact exoplanets and pulsations on M dwarfs by using radial velocity fiber-fed spectrographs. Specifically, she currently leads the HARPS-N observing campaigns of the project Cool Tiny Beats from which the Pale Red Dot was born, and she is also an editor of the website. Zaira is also actively involved in instrumentation development. In particular she is part of the team which is developing the Radial Velocity Corrector (RVC), an alternative to the scrambling methods for fiber-fed high-precision RV spectrographs which are non-thermally stabilized.