Klio Asteroid Occultation (21 / 01 /2012)

Often, amateur astronomers found that the universe doesn’t change quickly in our lives. Galaxies, nebulae and other objects appear to be motionless. Even in our solar system, comets and other objects seem to be still and we only perceive movement after several days. 

On the other hand, we only need to wait an hour to realize that something has changed in the vicinity of Jupiter. In general, there are few events in which something occurs rapidly, for instance, stars and TNOs occultation’s by asteroids. In this case we only need to stare at a star that will suddenly (if the event occurs) disappear behind a rocky object with some km in diameter. Concretely we are more interested in occultations of stars by TNOs with much more scientific interest nowadays. But since these are scarce and sometimes the weather was not very good, we took advantage of other events to gain experience.

A few days ago the asteroid 84/Klio with 78km in diameter and a 13º magnitude, hid for a few seconds the star TYC 2452 -01,336-1 in Gemini. Because the star had a magnitude of 11.4, it was necessary to make integrations of 2,188 seconds in order to detect it. The observation site was urban (a rooftop in the Albaicin, Granada, SPAIN) and through a LX200R 8 " with a 6.3 focal reducer, a QHY5 Monochrome video camera mounted on a computer-controlled CGEM with Cartes du ciel.

But the night did not start with this occultation. Only a few minutes before there was another favorable occultation from Granada. “Svea” was the asteroid and the star of magnitude 7.1 HIP26188 in Orion. So, we decided to observe both events, although the period of both occultation were overlapping in one minute. That is, we had to record Svea and be prepared to send the telescope accurately to Klio. We have to say that when the CGEM mount was polar aligned with EQAlign and synchronized it did a great job that allowed us to slew from one object to the other very fast and accuracy. Svea didn’t produce an occultation, at least from our position, but we had more luck with Klio. Right now we don’t have tools to analyze data and calculate the light curve, but this experience help us to accurately manage the CGEM and of course, enjoy a very nice spectacle in the night.