Auriga Nebula

Auriga Nebula Complex

A Coronal Mass Ejection (CME) is an eruption of gas and plasma from the Sun. Most head into space, away from Earth. When not away, it can cause geomagnetic storms, displays of aurorae, and/or disruption/damage to communications and electrical power grids.

Using the European Space Agency’s XMM-Newton space observatory and the LOFAR telescope, a research team has spotted a non-solar CME.

As a CME races through the layers of a star out into space, it produces a shock wave and a burst of radio waves. These short, intense radio signals were picked up and identified as coming from a star some 40 LYs away. This type of radio signal would not exist unless flaming material escaped the star’s bubble of powerful magnetism.

This star is a red dwarf, the most common type of star that generates energy through nuclear reactions in its core. These star types’ temperatures can reach 3,600°C. Most of the exoplanets (a planet existing beyond our solar system) so far discovered orbit this kind of star.

The Aurigae Nebula (IC 405) with the star of the same name inside:

A star illuminates the nebula, making it visible

The constellation Auriga, adorned with a bright yellowish Capella, has numerous star clusters and nebulae. The above image shows “The flaming star” AE Aurigae, and the nebula of the same name, which has the catalog number IC 405.

There are about 100 stars of such brightness in this constellation. The runaway star AE-Auriga is located in the densest region of the many gas & dust nebula. In the glow of the nebula, two processes are involved at once:

1. reflective (interstellar dust simply reflects and scatters the light of the star), and
2. emission (the real glow of clouds of hydrogen, covering 99% of the nebula).

Influenced by powerful Radiation/Emission of Acoustic (AE) waves from the star Aurigae, ultraviolet photons, emitted by the star, excite the hydrogen atoms of the interstellar nebula, which can extend across many light years.

These nebulae represent “visible nothingness,” but when concentrated in a small region of space, they give birth to possibly thousands of stars. Stars born in hydrogen clouds usually tend to leave the place of their birth.

The irregular AE-Aurigae star is not from the nebula, but just flying through it, like the stars of the Pleiades cluster.

Astronomers have been measuring its spectrum, temperature, distance, direction and speed of movement… It turns out that AE Aurigae is piercing this nebula like an interstellar cruiser, at a speed of over 200 km/sec, a lot faster than average stellar velocities in this part of the Milky Way.

Its trails led scientists to the very heart of the Orion Nebula, where the famous “Trapezium of Orion” now flaunts a multiple star system of very young luminaries. It was here, that AE Aurigae began its journey about 2-3Mio years ago.

Normally, a star is not a stellar cruiser, just flighing on its own. Only other stars can move stars! After lots of research, the scientists found its accomplice, the star Mu Columbae:

Sky-map: AE Aurigae, Mu Colubae, Orion Nebula (M42)

If we take the distance from the Orion Nebula to the central part of the constellation Auriga, where “The Flaming Star” AE Aurigae is now burning, and plot it in the opposite direction, we end up in the Columba constellation, where an equally young and hot star, with the same characteristics as the luminaries born in the Orion Nebula, flies through space at an equally very high speed. It is called Mu Columbae. It is literally the “twin” of the AE Aurigae star.

Only 2 Mio years ago, both luminaries formed a binary star system that slowly drifted through the veil of the nebula that gave birth to them. Then, they met another stellar pair, whose gravity confused their intensions. The balance in the system was lost and the binary stars scattered at high speeds in opposite directions, and will never meet again.

The linear distance to each of them from our solar system, is 1450 light years to AE Aurigae and 1300 light years to Mu Columbae. Thus, astronomers calculated that their linear separation is about the same, 1500 light years. This means that in 2.5 million years each star covered a path of about 750 light years from the Orion Nebula.

Scientists found the other stellar pair that was responsible for the destruction of our stellar twins. This is Iota Orionis, the brightest star in the Sword of Orion, still close to her birthplace. This star should also bear some traces of this “stellar incident”, 750 LY before.

Sky-map: Iota Orionis star

Iota Orionis turned out to be a spectrally binary star, meaning that even the most powerful telescopes cannot show the duality of the star. It is detected by spectral analysis, in such a way that it reveals the periodic bifurcation of the main absorption lines in the spectrum of the star.

When a telescope sees 1 light source, there are actually 2. One light-source moves towards the observer, the other moves away from her/him. Only the lines in the spectrum reflect this dynamic.

This is how the famous Doppler Effect manifests itself in stellar spectra, like the whistle of a locomotive that has a higher pitch if the locomotive is traveling in our direction. Not the sound, but the tone, the color character, of the stars changes slightly. The lines shift either towards the red end of the spectrum, or towards the blue end, because both sound and light are essentially waves. The red shift in the spectrum of distant galaxies is of the same nature.

Analyzing the spectrum of Iota Orionis, astronomers came to the conclusion that the orbit of its companion has an unusually high elongation. This does not happen in binary systems without an external reason. Someone else is needed to stretch the orbit of the stellar partner with their gravitational influence.

By comparing the scattering parameters of the stars AE Aurigae and Mu Columbae with the extreme orbit of the companion of Iota Orionis, astronomers managed to piece together the puzzle: these 4 stars are the main participants in a long-standing drama.

It is more complicated than it might seem at first glance. There are several scenarios. One of them is that initially AE Aurigae and Mu Columbae were not together, and one of them was a companion of Iota Orionis. The careless meeting at their stellar crossroads led to the stars exchanging partners, but only one pair survived. The newly created one.

This is a real cosmic “Soap opera” situation. This means that the life of stars is sometimes as fascinating as the life of people. Perhaps we, as Earthly humans, are only playing out scenarios of meetings and partings that are common to the stars in the entire Universe!

Stars like AE Aurigae don’t live very long, but before AE Aurigae will erupt as a Supernova, it will throw off its shell, and leave behind another nebula plus a small cinder of its stellar core, which will turn into a neutron star.

Auriga Nebula Complex: IC 410 and IC 405

There is another nebula next to IC 405, the IC 410, and comparable in size. It is called the Tadpoles Nebula, different from the “Tadpole Galaxy”.

The reason for that fancy name are the winding dust globules in the central part of the blueish nebula, as if some strange creatures with a large head and a wagging long tail were swimming in the abyss of the starry seas.

Although seemingly close together, the “Tadpoles Nebula” is 10 times further away than "The flaming Star Nebula”.

It is located near the edge of the Milky Way Galaxy, where stellar life still appears to be in full swing: new twin-stars are born, each with their own unique stellar fate.

Twin 5p stars