Solar environment

The term solar environment is often used in astronomy , but is not defined uniformly. The area that is understood as the vicinity of the sun can be understood as follows, depending on the astronomical research area:

From the point of view of planetology and aeronomy

See also : Planetology  and Aeronomy

• The outermost limit of the planetary system - around 60–100 astronomical units
• or the aphelias of the most distant long-period comets
• the so-called heliosphere

From the perspective of astrometry and stellar physics

See also : Astrometry  and Astrophysics

• the distance range of the closest fixed stars
  • up to 10 light years a total of 8 stars, u. a. Proxima and α Centauri , the arrow star , ... Sirius and Ross 154
  • up to 20 light years approx. 70 stars, including 61 Cygni (first distance measurement, Bessel 1838) and Prokyon (α in the small dog, winter hexagon) - both 11 light years away - and Kapteyn's star (red dwarf)
• all stars with a similar direction of movement (see sun apex )
• the spiral arm of the Milky Way , on the edge of which lies the solar system.

In galaxy research

Astronomers, on the other hand, speak of cosmic neighborhood - either the local group (the Milky Way, the Andromeda nebula and the respective companions) with distances of up to about 3 million light years, or the Virgo galaxy cluster up to about 70 million light years.