Gemini Nebula in the winter night

Date: 5./6.1.2016
Time: 19:00-23:30
Observing site: Ulvila observatory, Finland
Instrument: C280/2750mm (11” Catadioptric)

NELM: 5.3
SQM: 19.62
Darkness of the background sky: 4
Seeing: 2
Transparency: –
Weather: Clear sky, calm, -17C, snow on the ground, hazy sky, poor brightness of the sky because of winter condiions

Objects observed: NGC 2371-2

NGC 2371-2

I was observing at Ulvila observatory during the club evening of Porin Karhunvartijat. During the night, I observed a planetary nebula located in the constellation of Gemini, called “the Gemini Nebula”. The name is really good for the object, because it is located in the constellation of Gemini and because it visually looks like twin-planetary nebula! Actually it is a dual-lobed planetary nebula. In NGC catalogue it has been catalogued twice because of it visually appears as two separate objects. This object was really easy to find, it is located just 3 degrees SW from Castor, alpha Geminorum. I wrote following notes of my observation:

@8mm: A planetary nebula with two lobes. The long axis of the nebula is roughly in E-W orientation. The westernmost lobe (NGC 2371) is brighter, and there is a notable star-like brightening inside it. Nice object and pretty easy! OIII filter improves the view slightly. Observed with Hyperion 8-24mm zoom ocular.

160105-06_NGC 2371-2
NGC 2371-2 observed with 11” Catadioptric

Weather during the night was freezing, temperature was -17C , and there was already snow on the ground. Besides this, there was also some diamond dust (ice crystals) in the air. the combined effect of these factors was decreased sky darkness, which meant that the observing conditions were far from optimal. Nevertheless, I was still able to make at least one observation during the night! Besides observing this planetary nebula, I observed also four variable stars. After very mild early winter, we have now had real winter now also in Southern Finland since ~27th of December 2015. During the early days of January 2016, the temperature has plummetted to -20C, and we also have about 5 cm of snow on the ground.