Astronomers Discover ‘Interstellar Tunnel’ From Local Bubble With Solar System Towards Centaurus Constellation

A team of astronomers recently mapped the Local Hot Bubble, revealing not only unusual asymmetries in its shape and temperature gradient, but also a mysterious tunnel that leads toward the constellation Centaurus. The new data on the LHB’s configuration and temperature support the earlier hypothesis that it was formed by supernova explosions that expanded and heated the region. The tunnel, in turn, may indicate a possible connection to another nearby, low-density bubble.

Interestingly, the idea of ​​connecting all such bubbles left after supernova explosions as interstellar tunnels was put forward by NASA scientists exactly 50 years ago. The discovery made with the new instrument may be the first step in collecting evidence in favor of this hypothesis. The eROSITA telescope became the first X-ray instrument to observe the Universe from far beyond Earth. There is a large hydrogen halo around our planet, known as the geocorona. The geocorona extends more than 600 thousand km from the Earth’s surface. The solar wind interacts with hydrogen atoms in the geocorona, exciting scattered X-rays in it similar to those emitted by gas atoms in the Local Bubble. The eROSITA telescope is located at the L2 Lagrange point at a distance of 1.5 million km from Earth and does not suffer from interference in the geocorona.

Thanks to the eROSITA survey, the Local Bubble has received the most accurate description, including the determination of the temperature gradient. An impressive discovery was the detection of a “distinct relief” – a previously unknown tunnel with rarefied gas in the direction of the constellation Centaurus. In that direction there are several objects – two molecular clouds, the Gum Nebula, another nearby bubble, something else, but to which specific object the tunnel goes remains unclear.

It could also be a clue that the galaxy is made up of an interconnected network of hot bubbles and interstellar tunnels. This idea was proposed in 1974 but has not yet been confirmed. Perhaps scientists will soon be able to learn more about the recent history of our galaxy.