La Palma Observatory 
12-13 October 2022

@Bernard Foing


By Daphne Abbink

Bernard Foing, Daphne Abbink and Rosa Hoogenboom spent the nights of October 12 and 13 observing at the Isaac Newton Telescope, situated on the Roque de los Muchachos in La Palma. The near-infrared spectroscopic observations were targeted at several sightlines containing diffuse interstellar cloud material, with the aim to survey diffuse interstellar bands (DIBs) in this relatively unexplored wavelength regime.

The first night we enjoyed clear skies. Having already taken calibration exposures during the day, we had time to watch the sunset from above the clouds and later even to see the faint glimmer of the milky way just before moonrise. For most of the night we performed a continual cycle of taking exposures, moving the telescope to point at our next target, and taking more exposures. This was until, suddenly, the humidity alarm went off. A cloud was passing over the telescope dome. We closed the protective mirror cover and then the telescope dome to protect the mirror from any condensation resulting from the humidity. The dome could be reopened after about 50 minutes, and we could continue observing undisturbed until sunrise. We left the telescope that morning having obtained many precious spectra towards of almost al of our planned sightlines. During the second night, clouds covered the Roque de los Muchachos and the telescope domes on the mountain remained closed. The night in the Isaac Newton Telescope control room was spent analysing earlier observations, working out theoretical speculations, and giving a tour of the INT to the students who had been scheduled to observe at the nearby William Herschell Telesope.

Rosa will return to the INT in November for three more nights of observations, together with Milan Heinsohn Huala and Leander Schlarmann. All three nights will be dedicated to observing at a central wavelength that will push the instrument to observe beyond its recommended limit. We look forward to uncovering what we may learn from the new observations, and perhaps even to the discovery of new candidate diffuse interstellar bands.

@Bernard Foing

@Bernard Foing


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