Astronomers identify binary system believed to have invaded our solar system 70,000 years ago

[Judi Lynn]

Astronomers identify binary system believed to have invaded our solar system 70,000 years ago
By Anthony Wood
February 19, 2015



Artist's impression of Schulz's Star
(Image: Michael Osadciw/University of Rochester)

An international team of astronomers from the US, Europe, Chile, and South Africa have identified a star system that most likely passed through the outer edge of our solar system at a distance of 0.8 light years some 70,000 years ago. The rogue system, nicknamed Scholz's star, is comprised of a red dwarf with a mass of roughly eight percent of our parent star, while its partner, a brown dwarf, was found to be only six percent as massive as the Sun.

The discovery makes the star system the closest to have ever approached our own Sun, but the team believes it unlikely that it penetrated deep enough into the Oort cloud (a region of space outside the heliosphere thought to contain more than a trillion small icy bodies) to trigger a comet shower. However, it is possible that the system was visible at times from Earth.

Whilst the red dwarf would have been around 50 times too faint to observe with the naked eye at its closest approach to Earth, the unusual magnetic qualities of the binary system may have caused the star to flare to thousands of times its ordinary brightness. This flare may have been observed by our ancient ancestors, lasting for minutes or possibly even hours at a time.

To work out the rogue star system's trajectory, and calculate whether it had encroached on our solar system, the astronomers needed to work out the tangential velocity and the radial velocity of the red dwarf. The tangential velocity was ascertained by applying the Doppler shift method whilst observing light thrown out by the star, whilst radial velocity was discerned with the use of spectograph equipment fitted to the South African Large Telescope and the Magellen telescope at the Los Campanas Observatory, Chile.

More:
http://www.gizmag.com/binary-scholzs-star-solar-system/36173/

[tblue37]

1. Fascinating. KnR. nt

[Fred Sanders]

2. Some might like this video of the actual motion of the Sun and planets through space.....

[Judi Lynn]

3. OMG! <gulp!> That's wonderful. Thank you. n/t

[D Gary Grady]

4. Beautiful animation if not perfectly accurate

Astronomer and science popularizer Phil Plait has criticized the video as "wrong"

http://www.slate.com/blogs/bad_astronomy/2013/03/04/vortex_motion_viral_video_showing_sun_s_motion_through_galaxy_is_wrong.html

Astrophysicist Rhys Taylor is kinder, suggesting it's qualitatively OK if not completely accurate

http://astrorhysy.blogspot.cz/2013/12/and-yet-it-moves-but-not-like-that.html

and reasonably useful in picturing the overall motion.

He adds, "What honestly surprises me is that this is so incredibly popular on the internet. If you weren't aware that the Sun orbits the center of the galaxy - which, since the planets orbit it, necessitates that they trace out helical paths - then the education system has seriously failed." I think that's a bit overstated. It's quite possible to know that the planets orbit the Sun and that the Sun orbits our galaxy without ever having occasion to think about the overall picture (which among other things requires knowing the various velocities involved). Granted, there are plenty of people who aren't even clear on the difference between the solar system and the galaxy, or for that matter basic geography on our own planet.

Anyway, flawed details aside, the animation is well done and does a good job of getting across the basic idea, which most people have never really stopped to think about. That's probably what made it so popular on YouTube.