N:dlzc D:aol T:com (dlzc) wrote:
Dear Sam Wormley:

"Sam Wormley" wrote in message
news:70RQe.292294$_o.100507@attbi_s71...

N:dlzc D:aol T:com (dlzc) wrote:


Stable neutron stars are 0.8 solar masses. How far down will
you define "too small to detect"?

Tell me where you get this figure of 0.8 solar masses for stable
neutron stars. Thanks.


http://zebu.uoregon.edu/~imamura/122/mar13/bhform.html
... greater than 2-3 solar masses are unstable

http://www-astronomy.mps.ohio-state....3/extreme.html
... neutron degeneracy pressure can sustain 1.2 -2 solar masses

http://www.ma.utexas.edu/mp_arc/c/05/05-190.pdf
... graph on page 28 (still about 0.5 to 2.2 solar masses)

I may have remembered a particular neutron star's mass, rather
than the "only stable neutron star mass" "or the upper limit on
neutron star mass is". Sorry for any confusion this might have
created.

David A. Smith



Acording to my references, observed masses of neutron stars:
M_ns = 1.01 to 1.73 solar masses, so if you know of observations
down to 0.80 solar masses, I'm all ears to find the references.

Upper limit: M_ns 2.9 solar masses, including any possible
contribution due to rapid uniform rotation (Kalogera and Baym, 1996).

For stars that explode as Type II supernovae, the neutron star masses
average M_ns = 1.28 or 1.73 solar masses; the average for those arising
from Type Ib supernovae is M_ns = 1.32 solar masses. This compares
favorably with the determination of a neutron star mass of
M_ns = 1.35 ± 0.27 solar masses for 17 system (Thorsett et al., 1993).
Radio observtions for four neutron binary star systems give M_ns = 1.01
to 1.64 solar masses (Finn, 1994), while neutron star masses inferred
from X-ray bnaries lie in the range M_ns = 1 to 2 solar masses (Bahcall,
1978; Joss and Rappaport, 1984; Lang, 1992).

Thanks
-Sam