Does the sun wobble

Does the sun wobble?

Since many people come here with this question here the answer of Cornell.edu (owner and operator of astro-physics arXiv etc):

(The suns) motion is (..) a slight wobble(..)

So if you're afraid it could do any harm to you: definitively not.

But scientifically there is a more than huge difference between a stationary sun and a wobbling sun. This new knowledge changed our view to the universe completely. A whole new era started in astronomy leading to an explosion of our knowledge about the universe.

With the new knowledge of wobbling stars mankind learned that there are billions of other planetary systems out there in the universe. And perhaps a second earth too (New analysis assumes that there are at least 17 billion Earth-sized worlds in the Milky Way. See also here. Read especially the conclusions section.). These new found planets are called 'Exoplanets' and are among the hottest topics in today's science^[3]. It is the essence of scientific achievements to replace ancient crude approximations. Science knows no 'good enough approximation for most purposes'. Especially since this ignorance prevented the biggest scientific progress of this and the last century, that our galaxy is teeming with planetary systems. And this in contrast to the fact that just 25 years ago all scientists world wide agreed that our planetary system is the sole planetary system in the whole universe! Electricity has been known since the Greeks, but it was the scrutiny of men like Volta, Ampere, Ohm, Faraday and Maxwell who made electricity the easy to handle force we are using everyday in our houses, cities, trains, machinery.... If these men would have been satisfied with 'good enough approximations for most purposes' we would still live in candle lighted houses and steam-engines would lift our elevators to the 36. floor, our cities would still be gas-lighted and television and computers would be dreams of the far future..

Tau Ceti now delivered in the end of 2012 the all important proof: this star, which is only 12 light years away from us has been the target of one of the earliest searches for extraterrestrial life in the 60ths and 70ths. But astronomers couldn't find any hints of orbiting planets in the 60s through 90s. A recently completed re-examination, which especially considered the wobbling of the central star discovered five potential planets ranging from two to nearly seven times the mass of Earth, with orbits ranging from 14 to 640 Earth days long.

But the most exciting fact about this news is, that this discovery was made by purely re-analysing the old data, no new data was won. And mathematics hasn't changed a bit since the sixtieth of last century. It was the new knowledge about wobbling stars that led to the discovery of these exoplanets. Two of these planets could potentially be the closest habitable exoplanets yet discovered. So we will likely see soon many new discoveries on many more earlier examined stars.

The new knowledge that the barycentre of our solar system is not identical with the sun's centre has and had quite naturally many more scientific and practical implications and consequences (if you haven't heard about any of these important changes in the press or television you're not alone. Many physicists are not aware of them since these changes happen very secretly and very silently^[1] and unnoticed by the vast majority of the physics and even astronomy community. So the confusion is after more than twenty years still alive and still big: http://www.cv.nrao.edu/~rfisher/Ephemerides/times.html#TDB^[2]. This makes necessary even in 2010 such explanations as this one or this one from end of 2011.)

for the absolute first time ever in history mankind is able to locate it's correct position in the universe (this implicates numerous systematic errors in many different kinds of measurements made until recently. Although sun's orbit around the barycentre is small this matters since today's measurement accuracy - e.g. astrometry reaches the micro arc second level and frequency uncertainty of atomic clock's 10^-15 to 10^-17 - is high enough to reflect these errors. Besides this it should be clear that there are numerous other sources of error.)
HJD(Heliocentric Julian Date which was adjusted to the centre of the Sun) is now replaced by Barycentric Julian Date(BJD, TDB, TCB, see also here): HJD is now formally deprecated. Only some of the implications see here. If you're interested in the Fortran77 source code (conversion to C see one of my other sites) of the IAU TDB-TT conversion code, download it here. Online applets and IDL-source(UTC2BJD, BJD2UTC, HJD2BJD) can be found here. Further good explanations here ( except this objection ) . Only the adoption of this barycentric dynamical time allowed satellites to be reliably steered through the solar system.

adoption of the International Celestial Reference Frame (ICRF) as the standard reference frame (see here) to define the positions of the planets and the Earth and all other astronomical objects (the centre of this reference frame is the barycentre of our solar system) and the International Reference System (ICRS). The ICRS is 'quasi-inertial', what means that its fundamental axes do not rotate but "acceleration of the origin is allowed in opposition to the definition of the inertial reference system"(All forces from within our solar system cancel out in the solar system barycenter. The only force that is active is the attraction from the center of our galaxy), see e.g. here.

two resolutions were adopted at the International Astronomical Union XXIVth General Assembly (aug 2000) to allow high-accuracy studies of radial velocities and accurate comparisons between observers using different methods. The resolutions define a spectroscopic barycentric radialvelocity measure and an astrometric radial velocity. See also here.

transformation of GPS (Global Positioning System) to the Solar System Barycentric Frame (see especially the 'references' section, see also here)

centimeter/millimeter accuracy lunar laser observations by changing the reference frame to the solar system barycentre frame (use these papers as a starting point for your own investigations.)

etc etc....