Observing site: Preiviiki, Pori, Finland
Instrument: N250/1200 mm
Darkness of the background sky: 3
Weather: clear sky, fresh western wind, no Moon, no snow, +3 C
Objects observed: comet 46P/Wirtanen
Finally I was able to observe comet 46P/Wirtanen after several unsuccessfull attempts! I had been searching the comat for a couple of times before this, but then I realized, that I had been looking for in in a wrong place! I realized, that I hadn’t updated the orbital elements of the comet to my Skymap Pro, and because the orbits of comet change from perihelion to perihelion, my orbital elements were outdated. But after updating them, I was finally able to locate the comet!
In the before Finnish independence day (6th of December) me and couple of other active members of Porin Karhunvartijat went to Preiviiki, a couple of kilometers west from Pori city to observe the comet and also some other objects.
Weather during this observing session was windy and quite chilly! In the beginning of the session it was cloudy, but luckily the clouds went away, and we were able to observe this much anticipated comet!
The comet was easy to find, and it was barely visible also with naked eye with averted vision. The comet was clearly visible in the finderscope as a fuzzy, round object. In the ocular (with 38x magnification), the comet still looked like a fuzzy, round object, with very hazy, undefined outer edge. So only the coma of the comet was visible, there wasn’t any sign of visual tail. There was a central brightening in the middle of the coma, but no other features were visible. The comet looked pretty much what I had expected and did not offer many surprises, at least no visually.
In this case the comet was interesting also because it passed Earth at very close distance, only 0,08 AU! It is not very usual for a comet to come this close to Earth! Luckily it passed Earth safely, and it just provided some fun cometgazing for astronomy enthusiasts! Comet 46P/Wirtanen was found by American astronomer Carl A. Wirtanen in 17th of January 1948. This comet is very interesting for Finnish amateur astronomers also because the founder of comet is of Finnish ancestry and the comet has Finnish name! The founder of comet, Carl A. Wirtanen discovered several comets and minor planets during his career in Lick Observatory in California, USA.