[net.space] Extrasolar planets

dietz%usc-cse@USC-ECL@sri-unix.UUCP (08/22/83)

I've also heard that the Barnard's star data has been written off as
spurious.  A new interferometer is being built somewhere back east for
high precision astrometry.  The device should collect in a few hours
data that would have taken a year by previous techniques.  Accuracy is
a few milliarcseconds, good enough to detect Jupiter sized planets
around nearby stars.  The shuttle could orbit an interferometer
accurate to microarcseconds, which would allow the detection of earth
sized planets out to many light years, and Jovian planets out to great
distances.

 

dietz%usc-cse@USC-ECL@sri-unix.UUCP (08/24/83)

I've also heard that astronomers have detected something orbiting T
Tauri.  T Tauri was the first "T Tauri star" discovered.  It is
supposed to be a newly formed star with a very strong stellar wind.
The object detected has a mass 5-10 times that of Jupiter.  Since the
system isn't done forming,  astronomers aren't sure if the object will
become a star or just a very large planet.

 

dietz%usc-cse@USC-ECL@sri-unix.UUCP (08/28/83)

Science News reports that astronomers using a 1.5 meter astrometric
telescope in Flagstaff, Arizona have found "wobbles" around two stars,
indicating planet sized orbiting bodies.  One of the stars (I forget
its name) is a dim (yet glowing) body about 40 times the mass of
jupiter.  The mass can be determined since it is orbiting another star.
The article pointed out that some astronomers have (falsely) claimed
that Jupiter would have to be 80x larger to ignite fusion.

The same astronomers looked at Barnard's star, and found no evidence of
large planets there.  This directly contradicts earlier claims of
stellar motion caused by a superjovian planet.

 

REM@MIT-MC@sri-unix.UUCP (08/29/83)

From:  Robert Elton Maas <REM @ MIT-MC>

This is an astrophysics question: Small stars can't ignite hydrogen
fusion at all. Large stars ignite it and burn until it's virtually
exhausted, starting in the center and working outward until the helium
core is the whole star and the hydrogen outer part is infinitesimal.
Question, are there just-barely-stars which ignite hydrogen fusion in
their centers but can't maintain it and go out before the
burning-shell has reached the surface, leaving a helium core and a
hydrogen outer part permanently?