The human eye covers a limited range of wavelengths and telescopes can only record emissions in a certain region of the electromagnetic spectrum. However, the most modern image processing technologies allow them to be combined to appreciate the overwhelming complexity and beauty of the universe.
NASA experts have combined images of various space objects captured in visible light , infrared or X-rays , achieving a dazzling result. Since different wavelengths of light have different energies, this allows astronomers to better understand the energetic dynamics of these striking cosmic formations.
The contribution of the Chandra space telescope has been key in the five examples selected this week for publication. The team that processes the data from the Chandra X-ray Observatory is behind this extraordinary ‘constellation’ of photographs.
The cosmic object of the constellation of Aquarius designated with the letter ‘R’ (R Aquarii) consists of two stars located 650 light years from Earth : a red giant, known as the variable star Mira and a white dwarf without its own name . They are not perceived as two points of light, since both stars are closely interrelated. If you combine the Chandra X-ray images (in purple in the image), with the Hubble Space Telescope ‘s near-infrared and visible-light observations (red and blue), you can see the link between them.
As explained by NASA, the group forms a violent ‘dance of death’. One of the stars reaches the end of its ‘service life’, having lost at least half its mass, but when it shines it reaches a brightness 1,000 times greater than that of the Sun. In this sense, the dwarf can be considered a ‘dead’ star, since it exhausts its nuclear fuel, although as it expels matter, the red star absorbs it, accumulating on its surface. This occasionally results in huge thermonuclear explosions that launch such matter into outer space.
This interaction explains why we see not just two bright spots, but a lot of dust and gas in a nebula around the binary system, stirred by its gravitational interactions and explosive shock waves.
One of the best studied objects in the Milky Way is Cassiopeia A , located 11,000 light-years away . It is what astronomers consider to be a supernova remnant : they never saw the huge explosion that generated it, but they know that its place was taken by a very large star and they even know the heavy elements that constituted it. In fact, information collected by the Chandra telescope has allowed them to calculate that the remnant cloud contains the equivalent of 10,000 Earth masses of sulfur , 20,000 Earth masses of silicon, 70,000 Earth masses of iron, and 1 million Earth masses of oxygen.
NASA’s combined image includes one in X-rays and one in different ranges of the electromagnetic spectrum (dark purple, blue, and white from the Karl Jansky Very Large Array Observatory), in addition to optical data from the Hubble Telescope (orange) .
Today it is the brightest astronomical radio source in the night sky, recording frequencies above 1 GHz. Also impressive is the size of the expanding cloud of stellar material, which measures 10 light-years across.
