| Date 2018/12/15 Observation place New Mexico |
Technical
| Telescope | Planewave 431mm – 17″, 1940mm FL, f/4,5 with focal reducer |
| Mount | Planewave Ascension 200HR (FLI) |
| Imaging camera | Microline PL6303E (FLI) - regulated at -25o Celsius |
| Image type | Ha (RVsB) (Vs for synghetic green) |
| Exhibition | Ha (10 x 10 'bin 1 × 1), R and B (4 x 3' bin 2 × 2 each) |
| Pretreatment | Maxim DL |
| Treatment | Photoshop and PixInsight |
| Specific treatment | Create a synthetic green image |
Object description
| Object type | Emission nebula called "The Crab Nebula" |
| Constellation | Taurus |
| Visual magnitude | 8,4 |
| Distance | 6200 light years |
| Diameter | 13 light years |
| Dimension seen from Earth | 6 x 4 arc minutes |
| In visible light, the Crab Nebula is a large, oval mass of filaments, about 6 arc minutes long and 4 arc minutes wide, surrounding a diffuse central blue region. Recent analysis has shown that the star that exploded as a supernova and which is the origin of the Crab Nebula probably appeared in April or early May 1054, reaching a maximum apparent magnitude between -5 and -3 in July 1054. It was then brighter than all other objects in the night sky except the Moon. The filaments are the remnants of the supernova's atmosphere and are made up primarily of ionized helium and hydrogen as well as carbon, oxygen, nitrogen, iron, neon, and sulfur. At the very center of the nebula is a pulsar: a neutron star as massive as the Sun. The Crab pulsar spins around 30 times per second. M1 is a nebula very popular with amateur astronomers: with its magnitude of 8,4 and its size of 6 X 4 arc minutes, it is a target of choice for both visual observation and astrophotography. Visual observation should be made in a sky with low light pollution. The nebula is then visible as a faint spot with 7 × 50 or 10 × 50 binoculars. In telescopes 10 cm (4 inches) and larger in aperture, some details in its shape become apparent. Only under excellent viewing conditions and with telescopes of 40 cm (16 inches) or more aperture, can we possibly see the filaments and fine structures. In my picture, we can see the very beautiful red colored filaments that surround the central blue region of the nebula. To bring out these filaments as much as possible, I used an alpha Hydrogen (Ha) filter as a luminance image. For the color image, I chose the RGB filters (red and blue with a synthetic green produced with the red and blue images) in order to bring out the very beautiful natural colors of the nebula. |
| Richard Beauregard Sky Astro - CCD My impression "We cannot be alone in this gigantic universe" |