Transcript Iron-60 and Sun Formation

The Sun’s Crowded Delivery Room
• Telescopic observations
suggest that stars, even
isolated ones like the Sun,
form in clusters
• Meteorite studies can test
this idea and give
additional information
about events leading to
formation of the Solar
System
Moon
Cluster of new stars in the
constellation of Vela (Courtesy of
European Southern Observatory)
Iron-60 and Sun formation
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The Sun’s Crowded Delivery Room
• Precise analyses by Martin
Bizzarro and his colleagues
show that Earth, Mars, and
chondritic meteorites contain
evidence for the presence of
60Fe (given by the 0.0 value
of ε60Ni, the decay product of
60Fe)
• In contrast, differentiated
meteorites, which formed 1
My after initial solar system
formation, have no evidence
for 60Fe (low ε60Ni)
Iron-60 and Sun formation
COSMOCHEMISTRY iLLUSTRATED
The Sun’s Crowded Delivery Room
• In spite of having had no
60Fe, differentiated
meteorites did contain 26Al,
as did most early solar
system materials
• Martin Bizzarro and his
colleagues suggest:
–
Wolf-Rayet star --
26Al
was incorporated into the
interstellar cloud that gave birth
to the Sun when massive stars
spewed strong stellar winds
– 60Fe was added a million years
later when a massive star
exploded
Iron-60 and Sun formation
Stellar winds blowing from a massive
Wolf-Rayet star (brightest star near
center) in NGC 2359 Nebula. Courtesy
of P. Berlind & P. Challis, HarvardSmithsonian Center for Astrophysics.
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