The Spaghetti Nebula

The Spaghetti Nebula.

Simeis 147 (click the astronomical map above for an enlarged view), also known as the Spaghetti Nebula, SNR G180.0-01.7 or Sharpless 2-240, is a supernova remnant in the Milky Way, straddling the border between the constellations Auriga and  Taurus. Discovered in 1952 at the Crimean Astrophysical Observatory using a 25-inch Schmidt-Cassegrain telescope, it is difficult to observe due to its extremely low brightness. The nebulous area is fairly large with an almost spherical shell and filamentary structure. The remnant has an apparent diameter of approximately 3 degrees, an estimated distance of approximately 3000 (±350) light-years, and an age of approximately 40,000 years, the equivalent of eight Moons lined up side to side. There are two estimates of the distance to this nebula. The first put it some 880 parsecs (2,870 light years) away from the Earth, which would mean that Simeis 147 occupies a spherical volume with a diameter between 140 and 200 light years. If we consider that the distance to the nearest star, Proxima Centauri, is only 4.2 light years, we can imagine the huge dimensions of this astronomical object. This object is expanding at a velocity of around 100 km/sec and appears to have sufficient energy to emit radiation which includes gamma rays, as measured by the Fermi satellite. The size in the sky of the remains of this supernova is spectacular, in its interior, although not in the centre of the remains of the explosion, is the pulsar PSR J0538 + 2817, the nucleus of a massive and extremely concentrated star that rotates at high speed.

Recent studies suggest that the star that exploded was a massive star that had a similar star as a companion. When the latter exploded, the mass distribution varied and both were ejected at high speed. That is why the position of the pulsar does not coincide with the geometric centre of the supernova remnant, which is displaced just opposite to HD 37424, a giant star that would have shared the central position some 30,000 years ago.

A supernova is a cosmic phenomenon that happens in the last stellar evolutionary stages of a giant star’s life. It is characterized by one massive explosion that triggers the sudden appearance of a new bright star before gradually diminish over many weeks or months. The word “nova” is a Latin word meaning “new.” In astronomy, it refers to be a temporary new bright star. The “super” in supernovae signifies far less luminous. Meanwhile, the term supernova was established by Walter Baade and Fritz Zwicky in 1931. During the last thousand years, there was only three Milky Way supernova that was observed. Many were seen in other galaxies utilizing telescopes. The Kepler’s Supernova in 1604 was the most recent that was directly seen in the Milky Way. In the statically observation of supernovae, it indicates that supernova happens on average about three times every century in the Milky Way.

Credit: Instituto de Astroffsica de Canarieas, Steemit, Wikipedia.