M42 - Orion Nebula
M42 - Orion Nebula. Click here for full resolution image.
The Orion Nebula, or M42, is probably the most photographed deep sky object by amateur astronomers. It is one of the brightest nebulas on the night sky, can be seen by the naked eye, and can be easily found located just under the characteristic of Orion’s belt in the constellation of Orion.
The Orion Nebula is an area of very active star formation and is often considered a stellar nursery. It is relatively close-by, at a distance of about 1,344 lightyears from Earth. Due to its close proximity, it also has been studied a lot by professional astronomers. The nebula has learned us a lot about how stars are formed from contracting clouds of gas and dust. Astronomers have directly observed protoplanetary disks, brown dwarfs, intense and turbulent motions of the gas, and the photo-ionizing effects of massive nearby stars in the nebula.
The Orion Nebula is part of a much larger area called the Orion Molecular Cloud Complex, that extends several degrees over the night sky. Other objects in this complex include Barnard's Loop, the Horsehead Nebula, M43, M78, and the Flame Nebula.
Planning
Object
Visual Magnitude: 4.0
Apparent size: 85 x 60 arcmin
R.A.: 05h 36m 16.72s
Dec.: -05º 26’ 28.7”
Conditions
Astr. night: 19:29
Astr. dawn: 06:04
Moon: 39 %
Moon set: 12:08
This image of the Orion Nebula is the first astro-photograph ever taken at AstroWorldCreations. After initial nights just testing out equipment, trying to polar align the mount, work out the focusing, and assess the right camera settings, on February 08, 2018 the first real images of a deep sky object were taken. The Orion Nebula was chosen as it is one of the easier targets to photograph, while at the same time being a beautiful nebula to see.
The Orion Nebula is a typical winter object. Mostly during the months of December through February, the nebula reaches high enough altitudes to photograph during any length of time.
Capturing
At the time of this image, no dedicated astrophotography camera was available yet. Instead, a regular DSLR camera was used, a Canon 1Ds Mark III. The full-frame sensor of this camera, combined with the TOA-130 telescope gives a field of view of 2 degrees, more than enough to capture the 85 arcmin of the Orion Nebula. There was no automation applied in the capturing process whatsoever. After a three-star polar alignment using the manual mount control and the finder scope, the telescope was pointed at the target using the GOTO functionality from the mount. Focusing took place manually by zooming into an individual star in live-view and judging pinpoint sharpness on the LCD-screen on the back of the camera.
Exposure was somewhat of a guesstimate and set at 30s, using ISO800. The brightness of the nebula was high enough that such short exposures actually led to a decent overall image. A total of 21 frames were shot like this, resulting in a total of 10 minute total exposure.
Technical details
Telescope
Mount
Camera
Sensor Temp.
Takahashi TOA-130 + 35 flattener
10Micron GM1000HPS
Canon 1Ds MarkIII
-8ºC (ambient)
Exposures
OSC
Total Exposure
21 x 30s @ ISO800
0.18h
Processing
Since this was the first astro-photograph ever taken at AstroWorldCreations, very little was documented on the actual processing steps involved. A total of 19 Dark frames were shot under the same conditions as the actual images. In addition 10 flat frames were shot, and a few days later 14 Bias frames were shot under more or less similar conditions. The calibration frames were used in the (manual) processing of the images.
Since this was the first image processing ever done at AstroWorldCreations using PixInsight, it was decided to follow literally the steps for OSC images as described in the book ‘Inside PixInsight’, written by Warren Keller. Other than that, little is recorded as to the exact processing workflow. Many concepts and terminology were unknown at that time, so processing took several days, and went very slowly, step by step. But in the end a proper astro-photograph came out which was extremely rewarding and became the inspiration for many more photographs to come.
The first astro-image ever was printed and framed and is still hanging on the wall of the office:
