Another nebula, which resembles a head of an animal is designated NGC 2174, sometimes called Monkey Head Nebula. After capturing the Horse Head Nebula in the constellation Orion, I waited for a few days for good weather and pointed my telescope again into the Orion, this time to its northern part. Monkey Head Nebula is an HII region, which is approximately 6400 light-years away from Earth. To find a monkey is not that difficult. There is a baboon’s head on the upper left side, which is looking into the constellation Taurus.
The best way to capture this nebula is by using narrowband filters. For this purpose, I ordered a new monochrome camera ZWO 2600MM with a 2″ filter wheel. The filters are equally important as a camera, so I decided on Antlia 3 nm. As a first light, I must say that this combination works really well. I made in total 90 exposures, 5 minutes each, which means over 7 hours of integration time.
| Telescope | Newton 254/1000 mm |
| Aperture | 254 mm |
| Focal length | 950 mm |
| Mount | Gemini G53f |
| Autoguiding | ZWO 174MM, TS 60/240 mm |
| Camera | ZWO 2600MM @-10°C |
| Corrector | MaxField coma corrector |
| Filters | Antlia Ha, OIII, SII 3 nm |
| Exposure | 90x300s, Gain 100, bin 1x1, |
| Date | 2022-03-06 |
Long time since I hadn’t perused that blog. Your photos are magnificient! Just got two question for a soon-to-be astrophotographer:
I noticed lately you’ve been using the MaxField as coma corrector, whilst you mentioned the Explore Scientific as the best one in your test. Why?
Any reason you use a secondary tube to autoguide, rather than an off axis guider? (well it seems to work! It’s just that most people seem to point towards OAG as the best solution.)
Yes, this is the right question. At the time I wrote the coma corrector test, the MaxField wasn’t on the market. I purchased MaxField later on. The reason I am using it is that it reduces the focal length slightly. On the other hand, ExploreScientific prolongs the focal length slightly. In the end, you get a wider field of view, which matters. From coma correction, I am happy with MaxField.
Regarding the guide scope or OAG, the problem is that OAG is using the same focal length as your primary telescope. In my case 1000 mm. Sometimes it’s difficult to find a suitable star, but it depends on where you point your scope. With the guide scope, you don’t have this problem.