Category: Deep Sky

It was another good night at the River Ridge Observatory. There were five of us there imaging. It was much warmer and calmer than the night before so not having all those layers on was pleasant. My target for the night was the Jellyfish Nebula in Gemini.

This is a supernova remnant, similar to the better known Veil Nebula and Crab Nebula. The nebula is almost a degree wide or almost twice the apparent size of the Moon. It of course, is in the lower right quadrant. In the upper left quadrant is molecular gas, glowing in the Hydrogen alpha part of the spectrum and not related to the supernova remnant.

If you notice, near the top on the left is a star with a hint of blue nebulosity. The filter I used wouldn’t be any good at picking up reflection nebula and the star chart program does not show anything there but that is what it looks like.

This was three hours of data from five minute subs, taken with my 11″ SCT at f/1.9 using my NBZ UHS dual narrowband filter.

Saturday night was a good night at the River Ridge Observatory. First we had a meeting, via Zoom, of the Central Arkansas Astronomical Society, then the three of us who came to the RRO to image after did just that. About this time last year I learned of this nebula and managed to get a middling image of it. Next year, I said.

This is a total of 4.5 hours of data shot with an 11″ SCT at f/1.9 (with Hyperstar) and an IDAS NBZ UHS dual narrow band filter. The filter lets the red of Hydrogen Alpha and the blue/green of Oxygen III through but not much else. The nebula is a bubble of gas being pushed out by the bright star near the center, a so-called Wolf-Rayet star. The reddish glow outside the bubble is hydrogen gas lightly glowing. The nebula itself is about the apparent size of the Moon but is estimated to be 60 light years in diameter and 5,000 light years away.

Stacked with Deep Sky Stacker. Processed with Photoshop. I used a trial of StarXTerminator to separate the nebula from the stars. Starnet++ is free but this product is much easier and faster. The stars and nebula were processed separately then recombined.

Here is a link to last year’s image.

It was a cold night at the River Ridge Observatory last night. It was 25F when I left at 10:30. But there was no wind and no humidity, just a soul sucking cold that wanted to kill me.

I started with the California Nebula in Perseus which I intended to shoot with my dual narrowband IDAS NBZ UHS filter but apparently I can’t read or had the filters in the wrong cases and shot it with my broadband IDAS LPS D3 filter. The intended filter would have brought out the red better and blocked most everything else. The NBZ filter is for nebulae that glow on their own, the LPS is for nebulae that reflect light from nearby stars.

Then I moved to the Witch Head Nebula in Eridanus which I did intend to shoot with the broadband filter so I was all set. This picture is actually upside down but it doesn’t look like a face that way. It is lit up by the star Rigel just to its left from out point of view and both are about 900 light years away.