Winter observing in July
Remember me? Last month I was observing targets of the Kepler space mission at Teide Observatory on Tenerife. Now I am in Chile to observe targets of the CoRoT space mission. CoRoT is a satellite devoted to the study of stellar pulsations, and observes about 10 pulsating stars continuously for a period of 150 days, then moves on to the next 10 stars, and so on. By studying the light variations captured by CoRoT, we can obtain information about stellar oscillations, and through the oscillations we learn more about the stellar interior.
To understand the stellar oscillations better, we also study variations in the stellar spectrum. To do so, we observe the CoRoT targets with spectrographs from telescopes on the ground. To monitor the oscillations properly, we need to follow the stars over several weeks. Obtaining telescope time for many nights at the same telescope is very difficult! To solve this problem, we observe the same stars with different telescopes. For the CoRoT project we observe from Chile, France, Canary Islands, and New Zealand.
I am currently observing my fourth, and next-to-last night with the high-resolution spectrograph HARPS on the 3.6m telescope at the European Southern Observatory La Silla in Chile. The first two nights were perfect, but since yesterday we are fighting against the wind. If the wind blows faster than 15 m/s we cannot observe in the wind direction, and if the wind exceeds a speed of 20 m/s we have to close the dome. Yesterday I could not observe for most of the night. In Chile it is wintertime, which means that the nights are long. In good weather conditions I can observe for almost 12 hours per night!
La Silla is my favorite observatory, as the scenery and atmosphere are very magical. I love coming to observe here, which is on average once every 1.5 years. Several telescopes (with mirror sizes from 0.5m to 3.6m) are dotted on the mountain top, surrounded by the Atacama desert. Three weeks from now I will explore another observatory: McDonald Observatory in Texas, US. I am very excited as I have never observed there before!
Postcards from the Observatory