Articles tagged with "astronomy"
I went up onto the roof of the ESO building on a clear evening, and tried a star trail photo. I’d never done one from the city before but I thought it should be possible to do one, with the exposure set so that the buildings were not overexposed but at least some stars showed up. With a 4s exposure at ISO 100, this just about worked. So I took 500 of those and stacked them together, and got some decent trails. There was also someone coming down the trail from Alto del Naranjo to San Carlos de Apoquindo.
It had been totally clear when I started climbing but clouding over during the morning. By the time I got to the top it was starting to rain. I was going to go to the very highest point, but there was a sign asking people not to, so I didn’t.
I was planning to walk back down again but then it started hailing. Two tourists from New York were there, they had a car and they offered me a lift down. It was a better option than three hours walking in the hail.
I went to Roan Jase for a night to do some astrophotography with Julien and Jorge. Conditions were really good, though pretty savagely cold in late autumn, 1000m above sea level.
Trying to get an equatorial mount aligned is tricky. It would be easy enough in the northern hemisphere, where there’s a nice bright star near the celestial pole to target, but in the south there’s no bright pole star and we struggled to get the telescope well aligned. Shining the laser through the guide scope to see where we were pointing was our best technique.
I’d noticed the geostationary satellites a couple of times before on my photographs from Paranal. With this photograph I set out to capture as many as I could and then to identify them. I got a list of all of them, and then worked out the spatial scale of my photo and which direction I was pointing, so that I could work out which point of light was which satellite.
It’s very dark at Paranal but there’s still background light that we can’t do anything about: the atmosphere itself glows at night. It can be surprisingly bright. Often it’s green, when oxygen atoms are glowing. It can be red, too, when nitrogen is responsible. And it can be orange, when sodium atoms are being excited. Tonight, it was extremely orange, looking a lot like streetlights on clouds, except there were no clouds, and there are definitely no streetlights near here. It got really strong while I was taking a time lapse and you can see huge waves in the upper atmosphere rippling.