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Астронет: Астрономическая картинка дня RXJ1856.5-3754: возможно, звезда из кварков http://variable-stars.ru/db/msg/1175862/eng |
Credit & Copyright: M. van Kerkwijk
(Institute of Astronomy, Utrecht),
S. Kulkarni (Caltech),
VLT Kueyen, ESO
Explanation:
Why is RJX J185635-375 so cool and so dim?
Previously, this compact star held claim to being the
closest neutron star -- only 150
light-years away.
Now new observations and analysis indicate not only a
cool temperature for
RXJ J185635-375, pictured above,
but also a larger distance: roughly 450 light-years away.
Given an expected age of about one million years, this
neutron star should be significantly hotter and
brighter than we see it today.
One hypothesized solution holds hope a
RJX J185635-375 is actually a not a
neutron star but a
quark star -- something new.
Now quark stars are truly strange --
they may have made a transition to type of matter known as
strange
quarks.
Quark stars, were they to exist, would be intermediate between
neutron stars and
black holes in size and density.
Quark stars should be more compact and cool faster than neutron stars.
In fact, some might even be
ultracompact -- so dense that
lightitself can orbit.
Future observations will likely settle the
controversial claims of
RJX J185635-375's
distance and radiative geometry,
and hence determine if a previously undiscovered
type of beast roams the sky.
Authors & editors:
Robert Nemiroff
(MTU) &
Jerry Bonnell
(USRA)
NASA Web Site Statements, Warnings,
and Disclaimers
NASA Official: Jay Norris.
Specific
rights apply.
A service of:
LHEA at
NASA /
GSFC
& Michigan Tech. U.